JPH1187448A - Optical evaluator, optical evaluating method, method and apparatus for fabricating semiconductor device, method for managing semiconductor fabrication system and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for fabricating a semiconductor having desired characteristics accurately and uniformly through in-line control. SOLUTION: An n-type source region 108, an n-type drain region 109, and an n-type semiconductor region 101 are provided on a wafer 103. An interlayer insulation film 104 deposited on the wafer 103 is subjected to dry etching using plasma thus make openings 110a-110c reaching respective regions 108, 109 and 101 and then light etching for removing a damage layer is conducted. In this regard, the n-type semiconductor region 101 is irradiated intermittently with an exciting light 402 and the variation rate of the reflection intensity of a probe light 403 due to irradiation with the exciting light 402 is monitored in order to detect progress of removal of the damage layer or the extent of generation of new damage layer thus forming a small semiconductor device having uniform contact resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical evaluation apparatus, an optical evaluation method, a semiconductor device manufacturing method using optical evaluation, and a semiconductor device, which are suitable for in-line evaluation of characteristics in a semiconductor device manufacturing process. The present invention relates to a manufacturing apparatus, a method for managing a semiconductor device manufacturing apparatus, and a semiconductor device for use in optical evaluation.

[0002]

2. Description of the Related Art In recent years, high integration of semiconductor integrated circuits has been greatly advanced.
Although miniaturization and high performance of transistor elements have been attempted, particularly with the miniaturization of transistor elements, it has become necessary to realize highly reliable MOS devices. MOS
In order to improve the reliability of the device, it is necessary that each part constituting the MOS device has high reliability.

An important part that affects the reliability of such a MOS device is, for example, the reliability of a contact portion affected by a method of forming a contact window.
Damaged layers of the semiconductor substrate caused by dry etching used to form contact windows are removed by wet etching after dry etching. However, in order to properly judge the amount of removal, a monitor that is not conventionally used as a product is By measuring the electrical characteristics using a wafer or the like, the depth or the like of the damaged layer generated under the dry etching conditions can be grasped, and the wet etching for removing the damaged layer from the measurement result of the electrical characteristics can be performed. Conditions such as time and temperature are set. As described above, in the conventional method of manufacturing a semiconductor device, the processing conditions during the manufacturing process of the semiconductor device are controlled to be appropriate based on the electric characteristics obtained using the monitor wafer.

[0004] Among processes for forming each element of a semiconductor device, for example, an impurity introduction technique is an important step for determining the operating characteristics of the semiconductor device. The mainstream of impurity introduction is an ion implantation method, that is, a method in which ions are accelerated by an electric field and impurity ions enter a semiconductor substrate, an electrode, or the like. At that time, usually several tens keV
Impurity ions are accelerated by the energy of the ions to implant ions into a semiconductor substrate or the like. However, as a result of the implantation of the impurity ions, a damaged layer in which the crystallinity is lost is generated in the surface layer of the semiconductor substrate or the like. Further, the impurity is not activated as a carrier and the impurity concentration distribution is not desired. Is not distributed. Therefore, heat treatment (annealing) is performed after ion implantation in order to activate impurities, recover damage, and optimize the profile. Conventionally, the annealing process time, temperature, and the like have been determined by design (device simulation) and optimization of conditions, and annealing conditions have been basically set based on experience. In particular, an annealing process for recovering a surface defect layer of a semiconductor substrate has been based on experience.

[0005] Next, as for the gate insulating film used for the MOS device, the thickness of the gate insulating film is rapidly reduced, and it is expected that a very thin insulating film having a thickness of 4 nm or less will be used in the 21st century. MO having such an extremely thin insulating film
In the S device, the characteristics of the insulating film are said to determine the characteristics of the entire MOS device and the electric characteristics of the entire semiconductor integrated circuit, and the characteristics of the insulating film are particularly important.

The characteristics of such a gate insulating film have been
An S-capacitor or a MOS transistor was formed and managed by evaluating the electrical characteristics. The evaluation of the electric characteristics is performed during the manufacture of the MOS device or in the MOS device.
After the manufacture of the device, the wafer on which the MOS device is mounted is taken out of the chamber.

[0007]

However, with the above-mentioned miniaturization of MOS devices, etc., in the above-described etching step, impurity introduction step, and gate insulating film forming step, the above-described conventional evaluation methods use the following methods. There was such a problem.

First, there are the following problems in the etching step. While the planar size (lateral size) of the contact window is decreasing, the depth of the contact window is not reduced, and as a result, the aspect ratio (= depth / lateral size) is increasing. Then, in order to form a contact window having such a high aspect ratio, for example, in a dry etching process, high-vacuum, high-density plasma is used. In high vacuum and high density plasma processes,
The formation of a deep contact window is realized by using ions having high energy and uniform direction. However, due to the impact of ions having high energy, unlike the conventional level of defects caused by dry etching with relatively low vacuum and low density plasma, the depth and damage of the damage layer generated in the semiconductor crystal at the bottom of the contact are different. The degree is getting bigger. Also,
When the damage layer is evaluated using light in the microwave region (such as infrared light), since the light itself penetrates to a depth of 1 μm or more from the Si substrate, several tens of nanometers of actual plasma are used.
The level of damage to the Si substrate could not be accurately evaluated. In other words, accurate results cannot be given to the evaluation of a damaged layer or an extremely miniaturized region formed near the surface layer thinly with the miniaturization of the LSI in the future.

Therefore, it is difficult to reliably remove the damaged layer or to remove the damaged layer with good control only by using the conventional evaluation method.

Next, there are the following problems in the impurity introduction step and the annealing step. With the miniaturization of each element in a semiconductor device and the increasing importance of impurity introduction and profile control in microscopic regions, the setting of annealing conditions based on experience as described above often results in an optimum profile. There was a problem that the processing was terminated with no result or a defect remaining in the semiconductor substrate. Also,
In a situation where it is desired to shorten a desired semiconductor device development period, if the annealing conditions are optimized by a conventional process → analysis → process → analysis procedure, the development efficiency is significantly reduced. Therefore, recently, a process control technique based on an in-situ observation technique of an annealing process has been desired. Further, when heat treatment is performed using a single-wafer heat treatment apparatus, unlike conventional batch methods, slight variations in the amount of heat treatment between wafers have occurred due to variations in characteristics of the heat treatment apparatus and changes over time. . Furthermore, it was difficult to accurately grasp the actual dose at the time of impurity introduction and the effective impurity concentration introduced into the substrate after the heat treatment.

In the step of forming the gate insulating film, there are the following problems. In the case where the characteristics of the gate insulating film are managed by the above-described conventional evaluation of the electric characteristics, even if some trouble occurs in the insulating film forming process during the manufacture of the MOS device, the process is completed. Only when the wafer is taken out of the chamber and the electrical characteristics are evaluated, a defect is found only. Therefore, during that time, a defective gate insulating film is continuously formed, leading to a decrease in productivity (efficiency).

A first object of the present invention is to provide an in-line optical evaluation apparatus capable of surely grasping the factors affecting the characteristics of a semiconductor device during the above-mentioned manufacturing process in line and realizing good and uniform characteristics. It is to provide the method.

A second object of the present invention is to focus on the fact that there is a correlation between the optical characteristics of the semiconductor region and the state of the semiconductor region, and to evaluate various characteristics of the semiconductor device by utilizing the evaluation of the optical characteristics. It is an object of the present invention to provide a method of manufacturing a semiconductor device and a manufacturing apparatus for controlling the processing in-line.

A third object of the present invention is to provide a method of managing a semiconductor device manufacturing apparatus for performing maintenance of a chamber of the semiconductor device manufacturing apparatus by using a change in evaluation accuracy of optical characteristics.

A fourth object of the present invention is to provide a semiconductor device having a structure suitable for evaluating optical characteristics.

[0016]

In order to achieve the first object, according to the present invention, there are provided means relating to a first optical evaluation device described in claims 1 to 11, and claims 12 to
A means relating to the second optical evaluation device described in Item 22 and a means relating to the optical evaluation method described in Claims 34 to 43 are provided.

In order to achieve the second object, according to the present invention, means relating to an apparatus for manufacturing a semiconductor device according to claims 23 to 33, and means according to claims 44 to 61 and claim 6 are provided.
2 to 73, 74 to 84, 85 to 98, and 99 to 111, respectively.
Means relating to the third, fourth, and fifth semiconductor device manufacturing methods are taken.

In order to achieve the third object, the present invention provides means for managing a semiconductor device manufacturing apparatus according to the present invention.

In order to achieve the fourth object, in the present invention, means relating to a semiconductor device according to claims 124 to 128 are provided.

According to a first aspect of the present invention, there is provided an optical evaluation apparatus used when processing a substrate having a semiconductor region in a chamber. A first light source for generating excitation light, a second light source for generating measurement light, and intermittently irradiating the semiconductor region of the semiconductor substrate in the chamber with the excitation light generated by the first light source. A first light guide member for causing the semiconductor region to be irradiated with measurement light generated by the second light source, and a reflection of the measurement light applied to the semiconductor region. Reflectance detection means for detecting the reflectance, a third light guide member for causing the measurement light reflected from the semiconductor region to enter the reflectance detection means, and receiving an output of the reflectance detection means, The semiconductor region is irradiated with excitation light The difference between the reflectance of the measurement light when the excitation light is not irradiated and the difference between the reflectance of the measurement light when the excitation light is not irradiated is calculated as the change rate of the reflectance of the measurement light. And a change calculating means.

By using this optical evaluation device,
The following effects are obtained. When the semiconductor region is irradiated with excitation light guided by the first light guide member, carriers in the semiconductor region are excited, and an electric field is generated by the carriers. Due to this electric field, the reflectivity of the measurement light guided to the semiconductor region by the second light guide member changes depending on whether or not the excitation light is irradiated. It changes depending on the wavelength of light. On the other hand, if a defect serving as a recombination center of carriers is present in the semiconductor region, the life of the excited carriers is shortened, and the electric field intensity formed by the carriers is reduced. In other words, the change ratio of the reflectance with and without the excitation light irradiation changes depending on the number of defects and the like in the semiconductor region. Is calculated, the change rate of the reflectivity reflects the crystal state of the semiconductor region and the like. Therefore, the conditions of the processing performed in the chamber can be controlled based on the evaluation of the semiconductor region in-line.

According to a second aspect of the present invention, in the first aspect, the second light guide member is configured to cause the measurement light to enter the surface of the substrate from a direction substantially perpendicular to the surface. Is preferred.

Thus, the configuration is such that the measurement light is applied to the surface of the semiconductor substrate from a direction substantially perpendicular to the surface, so that a change in reflectance can be quickly and accurately evaluated for a small semiconductor region. That is, an optical evaluation device capable of performing an optical evaluation in a manufacturing process of a semiconductor device to be miniaturized is obtained.

According to a third aspect of the present invention, in the second aspect, the first light guide member is configured to cause the excitation light to enter the surface of the substrate from a direction substantially perpendicular thereto. Is preferred.

According to a fourth aspect of the present invention, in the third aspect, the optical axis adjustment is such that the excitation light and the measurement light are guided on the same optical axis and sent to the semiconductor region. Means for irradiating the second light guide member with the measuring light and the excitation light guided on the same optical axis by the optical axis adjusting means from a direction substantially perpendicular to the surface of the substrate, and It can be configured by a mirror that transmits the measurement light and the excitation light reflected from the semiconductor region upward.

According to the third or fourth aspect, the measurement light and the excitation light are irradiated from the direction substantially perpendicular to the surface of the semiconductor region. Therefore, even when the semiconductor region is extremely narrow, the change rate of the reflectance of the measurement light is used. Optical evaluation can be performed. Therefore, an optical evaluation device particularly suitable for detecting the state of the processing in the semiconductor region in real time can be obtained.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the measurement light reflected from the semiconductor region is received, the measurement light is separated, and then the reflectance is measured. The apparatus may further include a spectroscopy unit for sending the light to the detection unit.

Thus, information can be obtained over a wide range of wavelengths of the measurement light, and the rate of change of the reflectance of the measurement light in an appropriate wavelength range can be used according to the type of processing in the chamber. Will be possible.

According to a sixth aspect of the present invention, in any one of the first to third aspects, the first light source and the second light source are arranged so that the wavelength of the excitation light and the wavelength of the measurement light are different from each other. A beam splitter configured by a single common light source that generates a wide-spectrum light having a wavelength including a wavelength, and separating the broad-spectrum light generated by the common light source into excitation light and measurement light,
Further provided is a spectroscopic unit that receives the measurement light reflected from the semiconductor region, splits the measurement light, and then sends the split light to the reflectance detection unit. The first and second light guide members are configured to transmit the light from the splitter. It can be placed at the receiving position.

As a result, since the light source is unified, the structure of the optical evaluation device is extremely simplified.

According to a seventh aspect of the present invention, in the first aspect, the change calculating means is configured to measure a specific energy value of the measurement light which gives an extreme value in a spectrum of a change ratio of the reflectance of the measurement light. Only the change ratio of the light reflectance can be calculated.

Thus, it is possible to detect only a change in the reflectance of the measuring light having the most desirable specific wavelength. Therefore, high-sensitivity optical evaluation without noise is possible.

According to an eighth aspect of the present invention, in any one of the first to fourth aspects, receiving the measurement light reflected from the semiconductor region and transmitting only a specific wavelength range of the measurement light. And a filter for sending to the reflectance detecting means.

Thus, a change in the reflectance of light in a desired wavelength range can be detected without providing any spectral means.
The structure of the optical evaluation device is simplified, and high-sensitivity optical evaluation with little noise can be performed.

According to a ninth aspect, in the seventh or eighth aspect, the specific energy value of the measurement light is any value included in a range of 3.2 to 3.6 eV. Is preferred.

According to a tenth aspect, in the first aspect, it is preferable that the reflectance detecting means detects the reflectance of light in a wavelength range of 600 nm or less.

According to a tenth aspect of the present invention, in the tenth aspect, the reflectivity detecting means is 300 to 60.
More preferably, the reflectance of light in the wavelength range of 0 nm is detected.

According to a twelfth aspect, in any one of the first to eleventh aspects, the first light guide member irradiates the excitation light intermittently at a frequency of 1 kHz or less. It is preferable that it is comprised as follows.

As described in claim 13, in any one of claims 1 to 12, the optical evaluation device can be configured using an ellipsometry spectrometer.

This makes it possible to use an ellipsometry spectrometer member often provided in a chamber of a semiconductor device manufacturing apparatus, so that an optical evaluation apparatus can be obtained at low cost.

According to a second aspect of the present invention, there is provided an optical evaluation apparatus for evaluating electrical characteristics of an insulating film formed on a semiconductor region of a substrate. A first light source for generating excitation light, a second light source for generating measurement light, and a semiconductor directly under the excitation light generated by the first light source after passing through the insulating film. A first light guide member for intermittently irradiating the area;
A second light guide member for passing the measurement light generated by the second light source through the insulating film to irradiate the semiconductor region to which the excitation light is intermittently radiated; A reflectance detector for detecting the reflectance of the irradiated measurement light, and a third light guide member for causing the measurement light reflected from the semiconductor region to enter the reflectance detector.
Receiving the output of the reflectance detection means, when the semiconductor region is irradiated with the excitation light and the difference between the reflectance of the measurement light when the excitation light is not irradiated when the excitation light is not irradiated A change calculating means for calculating a change rate of the reflectance of the measurement light by dividing by the reflectance of the measurement light; and evaluating an electrical characteristic of the insulating film based on a magnitude of the change rate of the reflectance of the measurement light. Evaluation means.

As a result, information on electrical defects in the insulating film, particularly in the gate insulating film, can be obtained. That is,
When the semiconductor region is irradiated with the excitation light, the carriers are excited, and the electric field intensity changes with the change in the number of carriers, so that the reflectance of the measurement light in a certain wavelength region from the semiconductor region changes. At this time, if an insulating film is formed on the semiconductor region, a defect site serving as a carrier trap exists in the surface layer of the semiconductor region, so that the rate of change in the reflectance of the measurement light decreases. However, when the number of defects (trap electrons) in the insulating film is large, the amount of increase in the electric field strength in the adjacent semiconductor region increases, and the rate of change in the reflectance of the measurement light increases. Therefore, by the evaluation means,
By determining that the reflectance of the measurement light is out of the predetermined range, the electrical characteristics of the insulating film can be quickly and reliably managed.

According to a fifteenth aspect of the present invention, in the fourteenth aspect, the evaluation means includes the step of measuring the measurement light at a specific energy value of the measurement light that gives an extreme value in a spectrum of a change rate of the reflectance of the measurement light. Is determined to be non-defective only when the change ratio of the reflectance of the sample is a value corresponding to an appropriate capacitance value of the insulating film.

As described in claim 16, in claim 15, the specific energy value of the measurement light is
It can be any value within the range of 3.2 to 3.6 eV.

According to the fifteenth or sixteenth aspect, the optical evaluation is performed at the position where the sensitivity for detecting the difference in the electrical characteristics of the insulating film is the best in the spectrum of the change ratio of the reflectance showing the characteristic shape. Will be done.

According to a seventeenth aspect, in any one of the fourteenth to sixteenth aspects, receiving the measurement light reflected from the semiconductor region, dispersing the measurement light, and then measuring the reflectance. The apparatus may further include a spectroscopy unit for sending the light to the detection unit.

As a result, since the spectrum of the change rate of the reflectance of the measurement light is detected, it is possible to perform a highly accurate optical evaluation based on information on the entire spectrum shape.

[0048] As described in claim 18, according to any one of claims 14 to 16, receiving the measurement light reflected from the semiconductor region and corresponding to a specific energy value of the measurement light. And a filter for transmitting only the measurement light in the wavelength range to be transmitted to the reflectance detection means.

Thus, a change in reflectance in a desired wavelength range can be detected without providing a spectroscopic means, so that the structure of the optical evaluation device is simplified and quick optical evaluation becomes possible.

According to a nineteenth aspect, in the fourteenth aspect, it is preferable that the reflectivity detecting means detects the reflectivity of the measurement light in a wavelength range of 600 nm or less.

According to a twentieth aspect of the present invention, in the nineteenth aspect, the reflectivity detecting means may be 300 to 60.
More preferably, the reflectance of the measurement light in the wavelength range of 0 nm is detected.

According to claim 19 or 20, in particular, the fact that the measuring light in the visible light region and the wavelength region below it does not reach the depth of several hundred nm or more in the semiconductor region. The optical evaluation can be performed based on the change ratio of the reflectance from only the region affected by the trapped electrons.

As described in claim 21, in any one of claims 14 to 21, the optical evaluation device can be configured using an ellipsometry spectroscope.

This makes it possible to configure an optical evaluation device at low cost by using an ellipsometry spectrometer used for measuring the thickness of a gate oxide film or the like.

As described in claim 22, in any one of claims 14 to 21, it is preferable that the optical evaluation device is attached to a chamber used for forming an oxide film of a semiconductor device.

As a result, the quality of the insulating film can be evaluated without taking the semiconductor substrate out of the manufacturing apparatus, so that the evaluation apparatus is suitable for in-line characteristic evaluation.

According to a twenty-third aspect, in the fourteenth aspect, the second light source can be a Xe lamp.

According to a twenty-fourth aspect, in the fourteenth aspect, the first light source can be an Ar ion laser or a He—Ne laser.

According to a twenty-fifth aspect, in any one of the fourteenth to twenty-fourth aspects, the first light guide member irradiates the excitation light intermittently at a frequency of 1 kHz or less. It is preferable that it is comprised as follows.

According to a twenty-third aspect of the present invention, there is provided an apparatus for manufacturing a semiconductor device, comprising: a chamber for accommodating a substrate having a semiconductor region; and a chamber for processing the substrate in the chamber. Processing means; first light supply means for intermittently irradiating excitation light to a semiconductor region of the substrate provided in the chamber; and second light supply means for irradiating measurement light to the semiconductor region. A light supply unit, a reflectance detection unit that detects a reflectance of the measurement light applied to the semiconductor region, and an output when the semiconductor region is irradiated with excitation light by receiving an output of the reflectance detection unit. A change calculation that calculates a value obtained by dividing a difference between the reflectance of the measurement light when the light is not irradiated and the reflectance of the measurement light when the excitation light is not irradiated as a change ratio of the reflectance of the measurement light. Means and above During the course of processing by the Engineering processing unit, and a processing control means for receiving the output of the change computing means, for controlling the processing conditions on the basis of the change rate of the reflectance.

The following effects can be obtained by using this semiconductor device manufacturing apparatus. When the semiconductor region is irradiated with excitation light by the first light supply means, carriers are excited, and an electric field is generated by the carriers. Due to this electric field, the reflectivity of the measurement light supplied by the second light supply means changes between when the excitation light is irradiated and when it is not irradiated, and the rate of change depends on the magnitude of the electric field intensity and the measurement light. It changes depending on the wavelength. On the other hand, if a defect serving as a recombination center of carriers is present in the semiconductor region, the life of the excited carriers is shortened, and the electric field intensity formed by the carriers is reduced. In other words, the change ratio of the reflectance with and without the excitation light irradiation changes depending on the number of defects and the like in the semiconductor region. Is calculated, the change rate of the reflectivity reflects the crystal state of the semiconductor region and the like.
Then, the condition of the processing performed in the chamber is controlled by the processing control means based on the in-line evaluation of the semiconductor region, so that a semiconductor device having desired characteristics is formed with good reproducibility. .

According to a twenty-seventh aspect, in the twenty-sixth aspect, the processing means can generate plasma in the chamber to etch the semiconductor region.

This makes it possible to control the depth and the degree of damage of the damaged layer caused by the etching, so that the later damaged layer can be removed smoothly.

According to a twenty-eighth aspect of the present invention, in the twenty-sixth aspect, the processing means includes a light for generating a plasma in the chamber to remove a damaged layer generated by etching the semiconductor region. Dry etching may be performed.

Thus, it is possible to perform the light dry etching for removing the damaged layer after grasping the depth and the degree of damage of the damaged layer caused by the etching.

As set forth in claim 29, in claim 26, the processing means may introduce impurities into the semiconductor region.

This makes it possible to control the number of defects and the degree of defects caused by the introduction of impurities.

According to a thirty-seventh aspect, in the twenty-sixth aspect, the processing means may perform annealing after implanting impurity ions into the semiconductor region.

Thus, it is possible to perform annealing for efficiently and surely eliminating the disorder of the structure caused by the ion implantation of impurities.

According to a thirty-first aspect, in the twenty-sixth aspect, the processing means may form a thin insulating film on the semiconductor region.

Thus, an insulating film having desired characteristics, for example, a gate oxide film can be formed.

According to a thirty-second aspect, in the twenty-sixth aspect, when a thin insulating film is formed on the semiconductor region, the processing means is replaced with the insulating film on the semiconductor region. Dry etching for removing the film can be performed.

Thus, by utilizing the fact that the rate of change of the reflectance of the measurement light from the semiconductor region is affected by the thickness of the insulating film, the progress of removal of the insulating film is controlled by in-line optical evaluation. Becomes possible.

According to a thirty-third aspect, in any one of the twenty-sixth to thirty-second aspects, the first and second light supply means are provided between the surface of the substrate and the measurement light. Is preferably larger than the angle between the surface of the substrate and the excitation light.

As a result, it is possible to irradiate the measurement light to a narrow area, and it is possible to reduce the area of the semiconductor region required for measuring the reflectance of the measurement light.

According to a thirty-fourth aspect, in any one of the twenty-sixth to thirty-second aspects, the second light supply means irradiates measurement light from a direction substantially perpendicular to the surface of the substrate. You can do it.

Since the measuring beam is made to enter the semiconductor wafer from a direction substantially perpendicular thereto,
Optical measurement can be easily performed even when the semiconductor region is a very small region, and unnecessary space for optical monitoring can be saved, and detection sensitivity is improved, which is necessary for evaluation of optical characteristics. Time can be significantly reduced.

According to a thirty-fifth aspect, in the thirty-fourth aspect, it is preferable that the first light supply means irradiates excitation light from a direction substantially perpendicular to the surface of the substrate.

According to a thirty-sixth aspect, in any one of the twenty-seventh to thirty-fifth aspects, the first light supply means intermittently irradiates the excitation light with a frequency of 1 kHz or less. Is preferred.

According to a thirty-seventh aspect of the present invention, in any one of the twenty-sixth to thirty-sixth aspects, the second light supply means and the reflectance detection means are configured using an ellipsometry spectroscope. be able to.

As a result, it is possible to use the members of the ellipsometry spectrometer, which are often attached to the chamber of the semiconductor device manufacturing apparatus, so that the optical evaluation can be performed in-line while suppressing an increase in cost. Based on this, processing control can be performed.

According to the optical evaluation method of the present invention, an optical evaluation for evaluating a processing state when processing a substrate having a semiconductor region in a chamber is performed. Irradiating measurement light to a semiconductor region of the substrate in the chamber,
The step of intermittently irradiating the semiconductor region with excitation light, and the step of irradiating the semiconductor region with a difference in reflectance of measurement light between when the semiconductor region is irradiated with excitation light and when it is not irradiated with excitation light. Calculating a value obtained by dividing by a reflectance of the measuring light when it is not irradiated as a change ratio of the reflectance.

According to this method, when the semiconductor region is irradiated with the excitation light, the carriers in the semiconductor region are excited, and an electric field is generated by the carriers. Due to this electric field, the reflectance of the measurement light guided to the semiconductor region changes depending on whether or not there is excitation light irradiation, and the rate of change depends on the magnitude of the electric field intensity and the wavelength of the measurement light. Change. On the other hand, if the semiconductor region has a defect that becomes a recombination center of carriers,
Since the life of the excited carriers is shortened, the electric field intensity formed by the carriers is reduced. That is, since the change ratio of the reflectance with and without the irradiation of the excitation light changes depending on the number of defects and the like in the semiconductor region, the change ratio of the reflectance of the measurement light in the semiconductor region is calculated. Then, the rate of change of the reflectivity reflects the crystal state and the like of the semiconductor region. Therefore, it becomes possible to control the conditions of the processing performed in the chamber based on the in-line light modulation reflectance measurement.

According to a thirty-ninth aspect, in the thirty-eighth aspect, the step of irradiating the measurement light includes:
It is preferable that the measurement light is applied to the surface of the substrate from a direction substantially perpendicular to the surface.

According to this method, the light modulation reflectance can be measured even for a semiconductor region having a small area.

According to a forty-third aspect, in the thirty-eighth aspect, the step of irradiating the excitation light comprises:
Preferably, the excitation light is applied to the surface of the substrate from a direction substantially perpendicular to the surface.

According to claim 41, in any one of claims 38 to 40, the processing may be plasma etching of the semiconductor region.

As a result, it is possible to control the depth and the degree of damage of the damaged layer caused by the etching, so that the later damaged layer can be removed smoothly.

According to a twenty-second aspect, in any one of the thirty-eighth to thirty-fourth aspects, the processing is performed by a light dry process for removing a damaged layer caused by plasma etching of the semiconductor region. Etching can be used.

Thus, it is possible to perform the light dry etching for removing the damaged layer after grasping the depth and the degree of the damage of the damaged layer caused by the etching.

[0091] As described in claim 43, in any one of claims 38 to 40, the processing may be a process of introducing an impurity into the semiconductor region.

Thus, it is possible to control the number of defects and the degree of defects caused by the introduction of impurities.

[0093] As described in Item 44, in any one of Items 38 to 40, the processing may be annealing after implanting impurity ions into the semiconductor region.

As a result, it is possible to perform annealing for efficiently and surely eliminating structural disorder caused by impurity ion implantation.

[0095] As described in Item 45, in any one of Items 38 to 40, the processing may be to form an insulating film on the semiconductor region.

Thus, an insulating film having desired characteristics, for example, a gate oxide film can be formed.

[0097] As set forth in claim 46, in any one of claims 38 to 40, the processing is dry etching for removing an insulating film on the semiconductor region. it can.

Thus, utilizing the fact that the rate of change of the reflectance of the measurement light from the semiconductor region is affected by the thickness of the insulating film, the progress of removal of the insulating film is controlled by in-line light modulation reflectance measurement. It is possible to do.

As described in claim 47, in any one of claims 38 to 46, it is preferable that the semiconductor region is made of n-type silicon.

[0100] As described in Item 48, in any one of Items 38 to 47, in the step of irradiating the excitation light, the step of irradiating the excitation light intermittently at a frequency of 1 kHz or less. Is preferred.

The first method of manufacturing a semiconductor device according to the present invention
50. A first step of forming a substrate having a semiconductor region, a second step of evaluating optical characteristics of the semiconductor region, and a third step of etching the semiconductor region. And a fourth step of controlling the conditions of the etching process based on the optical characteristics of the semiconductor region evaluated in the second step.

According to this method, information relating to structural disorder near the surface of the semiconductor region can be obtained by utilizing the fact that the depth of light entering the semiconductor substrate is shallow, and this information can be used to etch the semiconductor device. During the process, the depth and the degree of damage of the damaged layer generated in the semiconductor region by the etching can be detected. Therefore, the characteristics of the semiconductor device can be controlled to a desired value accurately and with a small variation as compared with the conventional manufacturing method in which the electrical characteristics are detected after the etching step is completed, and the electrical characteristics are fed back to the etching conditions.

According to a fiftyth aspect of the present invention, in the fifty-ninth aspect, the second step includes irradiating the semiconductor region with measurement light, and irradiating the semiconductor region with excitation light intermittently. Step, the difference between the reflectance of the measurement light when the semiconductor region is irradiated with the excitation light and the time when the excitation light is not irradiated is the reflectance of the measurement light when the excitation light is not irradiated. Calculating the divided value as a change ratio of the reflectance of the measurement light.

The following effects can be obtained by this method.
When the semiconductor region is irradiated with the excitation light, carriers are excited, and an electric field is generated by the carriers. Because of this electric field, the reflectance of the measurement light changes depending on whether or not the excitation light is irradiated, and the rate of change changes depending on the magnitude of the electric field intensity and the wavelength of the measurement light. On the other hand, if a defect serving as a recombination center of carriers is present in the semiconductor region, the life of the excited carriers is shortened, and the electric field intensity formed by the carriers is reduced. In other words, the rate of change of the reflectance with and without the excitation light changes depending on the number of defects and the like in the semiconductor region. And so on. Therefore, if there is a damaged layer caused by etching, the depth of the damaged layer and the degree of damage can be known from the change ratio of the reflectance of the measurement light, so that appropriate etching conditions can be controlled.

According to a fifty-first aspect, in the fifty-fifth aspect, the step of calculating the change rate of the reflectance may include calculating the change rate of the reflectance of the measurement light in a wavelength range of 600 nm or less. preferable.

According to a fifty-second aspect, in the fifty-first aspect, in the step of calculating the change rate of the reflectance, the change rate of the reflectance of the measurement light in the wavelength range of 300 to 600 nm is calculated. Is preferred.

According to the method of claim 51 or 52, by utilizing the point that the measuring light in the visible light region penetrates to a depth of several 100 nm of the semiconductor, based on the information on the problematic region in the semiconductor device, The damaged layer in the semiconductor region can be removed.

According to a fifty-third aspect, in the fifty-fifth aspect, in the step of calculating the change rate of the reflectance, the step of calculating the change rate of the reflectance of the measurement light which gives an extreme value of the spectrum of the change rate of the reflectance of the measurement light It is preferable to calculate the rate of change of the reflectance of the measurement light at the specific energy value.

[0109] As described in Item 54, in Item 53, the specific energy value of the measurement light is:
It is preferable that the value be any value included in the range of 3.2 to 3.6 eV.

As set forth in claim 55, in any one of claims 50 to 54, in the step of irradiating the excitation light, the step of irradiating the excitation light intermittently at a frequency of 1 kHz or less. Is preferred.

[0111] As described in Item 56, in any one of Items 49 to 55, in the third step, dry etching using plasma can be performed.

Thus, the degree of damage to the semiconductor region caused by ion bombardment in plasma processing can be detected from the optical evaluation of the semiconductor region. A semiconductor device having good characteristics is formed.

According to a fifty-seventh aspect, in the fifty-sixth aspect, before the second step, a step of depositing an interlayer insulating film on the semiconductor region of the substrate; Selectively removing by plasma etching to form an opening reaching the semiconductor region. In the second step, the optical characteristic of the semiconductor region exposed at the bottom surface of the opening is changed. In the third step, the semiconductor region exposed at the bottom of the opening is subjected to light dry etching for removing a damaged layer caused by the plasma etching. In the fourth step, the semiconductor region is exposed. The conditions for the etching process can be controlled based on the evaluation results of the optical characteristics in the region.

Thus, when forming an opening serving as a contact hole, it is possible to suppress the occurrence of new damage due to excessive light dry etching while reliably removing the damage layer generated in the semiconductor region.

According to a fifty-eighth aspect of the present invention, in the fifty-seventh aspect, when a region where an element is formed in the semiconductor region is a source / drain region of an FET, the opening is formed in the source / drain region. It can be a contact hole reaching the drain.

According to this method, disturbance of the structure of the source / drain region can be minimized, so that an FET having good characteristics can be formed.

According to claim 59, in claim 58, the relationship between the optical characteristics of the semiconductor region and the depth of the damaged layer is determined in advance by an experiment, and
In the step, the depth of the damaged layer is obtained from the optical characteristics of the semiconductor region evaluated in the second step, and light dry etching can be performed so as to remove the semiconductor region corresponding to this depth.

According to this method, the damaged layer in the semiconductor region can be easily and quickly removed by one optical evaluation.

[0119] As described in Item 60, in the Item 57, in the fourth step, the optical characteristics of the semiconductor region, which change with the progress of the light dry etching, are re-evaluated. By comparing the re-evaluation result with the evaluation result in the second step, it is possible to control the condition of the etching process.

According to this method, when forming an opening which is a contact hole of a semiconductor device, it is possible to suppress the occurrence of new damage due to excessive light dry etching while reliably removing a damage layer generated in a semiconductor region. it can.

According to claim 61, in claim 60, when the region in which an element is formed in the semiconductor region is a source / drain region of an FET, the opening is formed in the source / drain region. It can be a contact hole reaching the drain region.

According to claim 62, in any one of claims 50 to 55, prior to the second step, a high concentration impurity is introduced into the semiconductor region of the substrate. Depositing an interlayer insulating film on the post-semiconductor region; and selectively removing the interlayer insulating film by plasma etching to form an opening reaching the semiconductor region. In the step, light dry etching is performed on the semiconductor region exposed at the bottom surface of the opening to remove a damaged layer caused by the plasma etching, and the measurement light when the electrical characteristics of the semiconductor region becomes appropriate. An appropriate range of the change ratio of the reflectance is obtained in advance, and in the fourth step, the license is set so that the change ratio of the reflectance falls within the appropriate range. It is possible to perform the dry etching.

This also makes it possible to reliably remove the damaged layer caused by dry etching.

[0124] As described in Item 63, in any one of Items 49 to 62, in the first step, the first semiconductor which is a part of a semiconductor element as the semiconductor region is provided. Forming a region and a second semiconductor region for performing an optical evaluation, in the second step,
The optical characteristics of the second semiconductor region are evaluated, and the third semiconductor region is evaluated.
In the step, the first and second semiconductor regions are etched at the same time, and in the fourth step, the conditions of the etching process are controlled based on the evaluation result of the optical characteristics in the second semiconductor region. be able to.

According to this method, the characteristics of the first semiconductor region where the semiconductor element is actually formed are not affected.
Since the size, impurity concentration, and the like of the second semiconductor region for performing the optical evaluation can be set to a state suitable for the optical evaluation, more accurate optical evaluation can be performed.

According to a sixty-fourth aspect, in the thirty-sixth aspect, in the first step, an impurity concentration in the second semiconductor region is higher than an impurity concentration in the first semiconductor region. can do.

According to this method, the sensitivity for performing the optical evaluation can be increased, so that the optical evaluation can be performed with high accuracy and speed.

According to a sixty-fifth aspect, in the thirty-sixth aspect, prior to the second step, after introducing a high-concentration impurity into the second semiconductor region of the substrate, the first And a step of depositing a gate insulating film and a gate electrode conductor film on the second semiconductor region. In the third step, the gate electrode conductor film and the gate insulating film are patterned by plasma etching. An appropriate range of the change rate of the reflectance of the measurement light when the electrical characteristics of the semiconductor region is appropriate is obtained in advance, and in the fourth step, the change rate of the reflectance falls within the appropriate range. The light dry etching can be performed as described above.

According to this method, it is possible to maintain the characteristics of the FET high while eliminating damage to the source / drain regions when forming the gate electrode of the FET.

As described in claim 66, in claim 65, a silicon oxide film can be formed as the gate insulating film.

According to claim 67, in any one of claims 49 to 66, in the first step, a portion of the semiconductor region for performing an optical evaluation is an n-type portion. It is preferred to be made of silicon.

As set forth in claim 68, in any one of claims 50 to 55, in the second step, the change rate of the reflectance of the measurement light using an ellipsometry spectrometer. Can be evaluated.

According to this method, an ellipsometry spectrometer, which is often attached to a semiconductor device manufacturing apparatus for measuring the thickness of an oxide film, is used to perform etching processing based on in-line optical evaluation. Control becomes possible.

The second method of manufacturing a semiconductor device according to the present invention
A method of manufacturing a semiconductor device having a semiconductor region in which a structural disorder has occurred, as described in claim 69,
Evaluating the optical characteristics of the semiconductor region; and performing a heat treatment for recovering the disorder of the structure of the semiconductor region while controlling conditions based on the optical characteristics of the semiconductor region evaluated in the step. And

According to this method, information relating to structural disorder near the surface of the semiconductor region can be obtained by utilizing the fact that light enters the semiconductor substrate at a shallow depth, and the heat treatment step can be controlled using this information. Becomes Therefore,
Accurately grasps structural disturbances such as crystallographic defects in the semiconductor region and deviations of the electronic structure from the normal state during the heat treatment process without causing a decrease in sensitivity or an increase in noise due to information from inside the semiconductor region. However, the normal characteristics of the semiconductor region can be restored under appropriate processing conditions without adversely affecting the characteristics of the semiconductor device.

As set forth in claim 70, in claim 69, the step of evaluating the optical characteristics includes:
Irradiating the semiconductor region with measurement light, irradiating the semiconductor region with excitation light intermittently, and when the semiconductor region is irradiated with excitation light and not irradiated with excitation light. Calculating a value obtained by dividing the difference in reflectance of the measurement light by the reflectance of the measurement light when the excitation light is not irradiated as a change ratio of the reflectance of the measurement light.

The following effects can be obtained by this method.
When the semiconductor region is irradiated with the excitation light, carriers are excited, and an electric field is generated by the carriers. Because of this electric field, the reflectance of the measurement light changes depending on whether or not the excitation light is irradiated, and the rate of change changes depending on the magnitude of the electric field intensity and the wavelength of the measurement light. On the other hand, if a defect serving as a recombination center of carriers is present in the semiconductor region, the life of the excited carriers is shortened, and the electric field intensity formed by the carriers is reduced. In other words, the rate of change of the reflectance with and without the excitation light changes depending on the number of defects and the like in the semiconductor region. And so on. Therefore, since the range and the degree of the disorder of the structure in the semiconductor region can be known from the change rate of the reflectance of the measurement light, it is possible to appropriately control the heat treatment conditions.

According to a seventy-first aspect of the present invention, in the step of calculating the change rate of the reflectance, the change rate of the reflectance of the measurement light in the wavelength range of 600 nm or less is calculated. preferable.

[0139] According to a seventy-second aspect, in the step of calculating the reflectance change ratio, the reflectance change ratio of the measurement light in the wavelength range of 300 to 600 nm is calculated. Is more preferred.

According to the method of claim 71 or 72, by utilizing the fact that the measuring light in the visible light region penetrates to a depth of several hundred nm of the semiconductor, based on the information on the problematic region in the semiconductor device, The recovery state of the semiconductor region can be controlled.

According to a thirty-seventh aspect of the present invention, in the seventy-seventh aspect, in the step of calculating the change rate of the reflectance, the step of calculating the change rate of the reflectance of the measurement light gives an extreme value of the spectrum of the change rate of the reflectance of the measurement light. It is preferable to calculate the rate of change of the reflectance of the measurement light at the specific energy value.

According to this method, the recovery state of the semiconductor region can be controlled simply, quickly, and accurately using the characteristic shape of the spectrum indicating the degree of change in the rate of change of the reflectance depending on the wavelength of the measuring light. Can be.

As set forth in claim 74, in claim 71, the specific energy value of the measuring light is:
It is preferable that the value be any value included in the range of 3.2 to 3.6 eV.

[0144] As described in Item 75, in any one of Items 70 to 74, in the step of irradiating the excitation light, the step of irradiating the excitation light intermittently at a frequency of 1 kHz or less. Is preferred.

As set forth in claim 76, in any one of claims 70 to 75, the change rate of the reflectance of the measurement light when the electrical characteristics of the semiconductor region are appropriate. In the step of determining the range in advance and performing the heat treatment on the semiconductor region, the heat treatment can be performed such that the change ratio of the reflectance of the measurement light falls within the appropriate range.

According to this method, variation in the characteristics of the semiconductor region after heat treatment between lots can be reduced as much as possible.

As described in claim 77, 70
75, the relationship between the change ratio of the reflectance of the measurement light in the semiconductor region and the impurity concentration in the semiconductor region is determined in advance, and the step of performing the heat treatment includes: The heat treatment of the semiconductor device is preferably performed until the change rate of the reflectance of the measurement light becomes a change rate corresponding to a desired impurity concentration.

According to this method, variations in the impurity concentration and impurity diffusion state of the semiconductor region between lots can be reduced as much as possible. Therefore, it is possible to form a semiconductor device having a good impurity concentration distribution state and a small variation in characteristics between wafers.

[0149] As described in Item 78, in any one of Items 69 to 77, the first semiconductor region, which is a part of a semiconductor element, is optically evaluated in advance as the semiconductor region. In the step of forming a second semiconductor region to be performed and evaluating the optical characteristics,
In the step of evaluating the optical characteristics of the second semiconductor region and performing the heat treatment, the heat treatment of the first and second semiconductor regions may be performed while simultaneously evaluating the optical characteristics of the second semiconductor region. Based on this, the conditions of the heat treatment can be controlled.

According to this method, without affecting the characteristics of the first semiconductor region where the semiconductor element is actually formed,
Since the size, impurity concentration, and the like of the second semiconductor region for performing the optical evaluation can be set to a state suitable for the optical evaluation, more accurate optical evaluation can be performed.

As set forth in claim 79, in claim 78, in the first step, the impurity concentration in the second semiconductor region is higher than the impurity concentration in the first semiconductor region. can do.

According to this method, the sensitivity for performing the optical evaluation can be increased, so that the optical evaluation can be performed with high accuracy and quickly.

As described in Item 80, in any one of Items 69 to 79, it is preferable that a portion for performing an optical evaluation in the semiconductor region is made of n-type silicon. .

[0154] As described in Item 81, in any one of Items 69 to 80, a region for forming a semiconductor element in the semiconductor region may be a source / drain region.

According to this method, it is possible to form a FET having good characteristics by performing a heat treatment for eliminating disorder in the structure of the source / drain regions of the FET.

[0156] As described in Item 82, in any one of Items 70 to 77, in the second step, the change ratio of the reflectance of the measurement light using an ellipsometry spectrometer is used. Can be evaluated.

According to this method, an ellipsometry spectroscope, which is often provided in a semiconductor device manufacturing apparatus for measuring the thickness of an oxide film, is used to perform etching processing based on in-line optical evaluation. Control becomes possible.

The third method of manufacturing a semiconductor device according to the present invention
84. A method of manufacturing a semiconductor device having a semiconductor region as set forth in claim 83, wherein a step of evaluating optical characteristics of the semiconductor region, and a step of evaluating optical characteristics of the semiconductor region evaluated in the step. And introducing an impurity into the semiconductor region while controlling the conditions based on the conditions.

According to this method, information relating to the disorder of the structure near the surface of the semiconductor region can be obtained by utilizing the fact that the depth at which light enters the semiconductor substrate is shallow, and control of the impurity introduction step using this information can be performed. It becomes possible. In other words, it is possible to accurately detect structural disturbances such as crystallographic defects and electronic structure deviations from a normal state caused by impurity introduction without causing a decrease in sensitivity and an increase in noise due to information from inside the semiconductor region. Can be grasped or predicted.

[0160] As described in Item 84, in the Item 83, the step of evaluating the optical characteristics includes:
Irradiating the semiconductor region with measurement light, irradiating the semiconductor region with excitation light intermittently, and when the semiconductor region is irradiated with excitation light and not irradiated with excitation light. Calculating a value obtained by dividing the difference in reflectance of the measurement light by the reflectance of the measurement light when the excitation light is not irradiated as a change ratio of the reflectance of the measurement light.

The following effects are obtained by this method.
When the semiconductor region is irradiated with the excitation light, carriers are excited, and an electric field is generated by the carriers. Because of this electric field, the reflectance of the measurement light changes depending on whether or not the excitation light is irradiated, and the rate of change changes depending on the magnitude of the electric field intensity and the wavelength of the measurement light. On the other hand, if a defect serving as a recombination center of carriers is present in the semiconductor region, the life of the excited carriers is shortened, and the electric field intensity formed by the carriers is reduced. In other words, the rate of change of the reflectance with and without the excitation light changes depending on the number of defects and the like in the semiconductor region. And so on. Therefore, since the range and the degree of the structural disorder in the semiconductor region can be known from the change ratio of the reflectance of the measurement light, it is possible to appropriately control the impurity introduction condition.

As set forth in Claim 85, in the calculating step of calculating the change rate of the reflectance, the change rate of the reflectance of the measurement light in the wavelength range of 600 nm or less may be calculated. preferable.

According to the 86th aspect of the present invention, in the 85th aspect, the step of calculating the change rate of the reflectivity includes calculating the change rate of the reflectivity of the measurement light in the wavelength range of 300 to 600 nm. Is more preferred.

According to the method of claim 85 or 86, based on the fact that the measuring light in the visible light region has the property of penetrating to a depth of several 100 nm of the semiconductor, based on the information on the region that is problematic in the semiconductor device, The introduction of impurities into the semiconductor region can be controlled.

[0165] As described in Item 87, in Step 84, in the step of calculating the change rate of the reflectivity, the step of calculating the change rate of the reflectivity of the measurement light that gives an almost extreme value of the spectrum of the change rate of the reflectivity of the measurement light. The change rate of the reflectance of the measurement light at the specific energy value can be calculated.

According to this method, the recovery state of the semiconductor region can be simply, quickly and accurately controlled while utilizing the characteristic shape of the spectrum indicating the degree of change in the rate of change of the reflectance depending on the wavelength of the measuring light. Can be.

As described in claim 88, in claim 87, the specific energy value of the measuring light is:
It is preferable that the value be any value included in the range of 3.2 to 3.6 eV.

[0168] As described in Item 89, in any one of Items 84 to 88, in the step of irradiating the excitation light, the step of irradiating the excitation light intermittently at a frequency of 1 kHz or less. Is preferred.

As set forth in claim 90, in any one of claims 84 to 89, the relationship between the amount of impurity introduced and the change rate of the reflectance of the measurement light is determined in advance by an experiment. In addition, in the step of introducing an impurity into the semiconductor region, the impurity can be introduced such that the change rate of the reflectance of the measurement light becomes a value corresponding to a desired amount of the introduced impurity.

According to this method, variations in the impurity concentration and impurity diffusion state of the semiconductor region between lots can be reduced as much as possible. Therefore, it is possible to form a semiconductor device having a good impurity concentration distribution state and a small variation in characteristics between wafers.

As set forth in claim 91, in any one of claims 83 to 90, the first semiconductor region, which is to be a part of a semiconductor element, is optically evaluated in advance as the semiconductor region. In the step of forming a second semiconductor region to be performed and evaluating the optical characteristics,
In the step of evaluating the optical characteristics of the second semiconductor region and introducing the impurity, the step of introducing the impurity into the first and second semiconductor regions simultaneously may be performed while simultaneously introducing the impurity into the first and second semiconductor regions. The conditions for the introduction of the impurities can be controlled based on the evaluation results of the above.

According to this method, the characteristics of the first semiconductor region where the semiconductor element is actually formed are not affected.
Since the size, impurity concentration, and the like of the second semiconductor region for performing the optical evaluation can be set to a state suitable for the optical evaluation, more accurate optical evaluation can be performed.

As described in Item 92, in any one of Items 83 to 91, in the third step, the introduction of the impurity can be performed by plasma doping.

According to this method, in the case of plasma doping, a change in optical characteristics such as a rate of change in reflectance gradually increasing or decreasing according to an increase in the amount of impurity introduced can be used. The controllability of the introduction process is improved.

As set forth in claim 93, in any one of claims 83 to 92, the impurity is preferably an n-type impurity.

As set forth in claim 94, in any one of claims 83 to 93, a region of the semiconductor region where a semiconductor element is formed can be a source / drain region.

According to this method, the impurity concentration in the source / drain regions of the FET can be controlled with high precision, and thus it is possible to form an FET having good characteristics.

[0178] As described in Item 95, in any one of Items 84 to 90, in the second step, the change ratio of the reflectance of the measurement light using an ellipsometry spectrometer is used. Can be evaluated.

According to this method, an ellipsometry spectrometer, which is often attached to a semiconductor device manufacturing apparatus for measuring the thickness of an oxide film, etc., is used to introduce impurities based on in-line optical evaluation. Control becomes possible.

The fourth method of manufacturing a semiconductor device according to the present invention
97. A first step for forming a substrate having a semiconductor region, a second step for evaluating optical characteristics of the semiconductor region, and a thin insulating film on the semiconductor region as set forth in claim 96. And a fourth step of controlling the conditions for forming the insulating film based on the optical characteristics of the semiconductor region evaluated in the second step.

According to this method, information relating to the characteristics of the insulating film on the semiconductor region can be obtained by utilizing the fact that the depth at which light enters the semiconductor substrate is shallow, and the control of the insulating film forming process using this information can be performed. It becomes possible. Therefore, it is necessary to form the insulating film under appropriate conditions while accurately grasping the quality of the insulating film in the insulating film forming process without causing a decrease in sensitivity or an increase in noise due to information from inside the semiconductor region. Can be.

As described in claim 97, in claim 96, in the second step, the semiconductor region is irradiated with measurement light, and the semiconductor region is irradiated intermittently with excitation light. Step, the difference between the reflectance of the measurement light when the semiconductor region is irradiated with excitation light and the time when the excitation light is not irradiated with the reflectance of the measurement light when the excitation light is not irradiated. Calculating the divided value as a change ratio of the reflectance of the measurement light.

According to this method, information on an electrical defect in the insulating film can be obtained. That is, when the semiconductor region is irradiated with the excitation light, the carriers are excited, and the electric field intensity changes with the change in the number of carriers, so that the reflectance of the measurement light in a certain wavelength region from the semiconductor region changes.
At this time, if an insulating film is formed on the semiconductor region, a defect site serving as a carrier trap exists in the surface layer of the semiconductor region, so that the rate of change in the reflectance of the measurement light decreases. However, when the number of defects (trap electrons) in the insulating film is large, the amount of increase in the electric field strength in the adjacent semiconductor region increases, and the rate of change in the reflectance of the measurement light increases. Therefore, the quality of the insulating film can be quickly and reliably determined based on the magnitude of the change rate of the reflectance of the measurement light.

As set forth in claim 98, in the step of calculating the change rate of the reflectance, the change rate of the reflectance of the measurement light in the wavelength range of 600 nm or less may be calculated. preferable.

As set forth in claim 99, in the step 98, the step of calculating the change rate of the reflectivity includes calculating the change rate of the reflectivity of the measuring light in the wavelength range of 300 nm to 600 nm. Is more preferred.

According to the method of claim 98 or 99, since the measuring light in the wavelength region shorter than the visible light is used, particularly, the region where light enters the semiconductor region can be made shallow, and the sensitivity is degraded due to the internal information. Can be avoided.

[0187] As described in Item 100, in the method of Item 97, the step of calculating the change rate of the reflectance may include the step of calculating the change rate of the reflectance of the measurement light, which gives an extreme value of the spectrum of the change rate of the reflectance of the measurement light. The change rate of the reflectance of the measurement light at the specific energy value can be calculated.

According to this method, it is possible to easily, quickly and accurately control the state of formation of the insulating film while utilizing the characteristic shape of the spectrum indicating the degree of change in the reflectance change rate depending on the wavelength of the measuring light. Can be.

[0189] As described in Item 101, in Item 100, the specific energy value of the measurement light is preferably any value included in a range of 3.2 to 3.6 eV.

According to the present invention, in the step of irradiating the excitation light, the excitation light is intermittently radiated at a frequency of 1 kHz or less. Is preferred.

[0191] As described in claim 103, in any one of claims 97 to 102, the change rate of the reflectance of the measurement light corresponding to the appropriate range of the electrical characteristics of the insulating film is previously determined by an experiment. In the fourth step, the insulating film can be formed such that the rate of change of the reflectance of the measurement light evaluated in the second step falls within the appropriate range.

According to this method, variations in the electrical characteristics of the insulating film between lots can be reduced as much as possible.

[0193] As described in Item 104, in any one of Items 97 to 103, in the second step, the reflection of the measurement light in the semiconductor region before the formation of the insulating film is performed. In the fourth step, the rate of change of the reflectance of the measurement light in the semiconductor region, which changes in accordance with the progress of the formation of the insulating film, is reevaluated. The conditions for forming the insulating film can be controlled by comparing the results of the evaluation in the second step.

According to this method, an insulating film having desired electric characteristics can be easily formed.

[0196] As described in Item 105, in any one of Items 96 to 104, in the first step, the first semiconductor which is a part of a semiconductor element as the semiconductor region is provided. Forming a region and a second semiconductor region for performing an optical evaluation; in the second step, evaluating the optical characteristics of the second semiconductor region; in the third step, the first semiconductor region; And simultaneously forming an insulating film on the second semiconductor region, and in the fourth step,
The formation condition of the insulating film can be controlled based on the evaluation result of the optical characteristics in the second semiconductor region.

According to this method, the characteristics of the first semiconductor region where the semiconductor element is actually formed are not affected.
Since the size, impurity concentration, and the like of the second semiconductor region for performing the optical evaluation can be set to a state suitable for the optical evaluation, more accurate optical evaluation can be performed.

According to a tenth aspect, in the first aspect, in the first step, the impurity concentration in the second semiconductor region is higher than the impurity concentration in the first semiconductor region. can do.

According to this method, the sensitivity for performing the optical evaluation can be increased, so that the optical evaluation can be performed with high accuracy and quickly.

As described in Item 107, in any one of Items 96 to 106, in the first step, a portion for performing an optical evaluation in the semiconductor region is an n-type portion. It is preferred to be made of silicon.

[0200] As described in Item 108, in any one of Items 97 to 104, after the fourth step, the change ratio of the reflectance of the measurement light, which is obtained in advance by an experiment, can be determined. The method may further include determining whether the formed insulating film is good or bad based on the relationship with the electrical characteristics of the insulating film.

According to this method, it is possible to take measures such as re-forming the insulating film on the substrate on which the defective insulating film is formed, or stopping the subsequent steps.

[0202] As described in Item 109, in any one of Items 96 to 108, it is preferable that in the third step, a silicon oxide film is formed as the insulating film.

[0203] As described in Item 110, in any one of Items 96 to 109, in the third step, a gate insulating film can be formed as the insulating film.

According to this method, control for improving the electric characteristics of the gate insulating film, which largely affects the performance of the FET, can be performed.

[0205] As described in Item 111, in any one of Items 97 to 104, in the second step, the change ratio of the reflectance of the measurement light using an ellipsometry spectrometer is used. Can be evaluated.

According to this method, an insulating film is formed based on an in-line optical evaluation using an ellipsometry spectrometer which is often attached to a semiconductor device manufacturing apparatus for measuring the thickness of an oxide film. Can be controlled.

The fifth method of manufacturing a semiconductor device according to the present invention
112. A first step of forming a substrate having a semiconductor region and a thin insulating film thereon, a second step of evaluating an optical characteristic of the semiconductor region, A third step of removing the insulating film by dry etching; and a fourth step of controlling a removing condition of the insulating film based on the optical characteristics of the semiconductor region evaluated in the second step. I have.

According to this method, information regarding the presence or absence of an insulating film on a semiconductor region can be obtained by utilizing the fact that the depth of light entering the semiconductor substrate is shallow, and control of the insulating film removing step using this information can be performed. It becomes possible. Therefore, the etching for removing the insulating film can be completed at an appropriate timing without causing a large damage to the semiconductor region without causing a decrease in sensitivity or an increase in noise due to information from inside the semiconductor region.

[0209] As set forth in claim 113, in the claim 112, the second step is a step of irradiating the semiconductor region with a measurement light passed through the insulating film, and the step of irradiating the semiconductor region with the measurement light. Intermittently irradiating excitation light that has passed through the insulating film; and determining the difference in reflectivity of measurement light between when the semiconductor region is irradiated with excitation light and when the excitation light is not irradiated. Calculating a value divided by the reflectance of the measurement light when the light is not irradiated as a change rate of the reflectance of the measurement light.

According to this method, the carrier is excited when the semiconductor region is irradiated with the excitation light, and the electric field intensity changes in accordance with the change in the number of carriers. Therefore, the reflectance of the measurement light in a certain wavelength region from the semiconductor region is reduced. Change. At this time, if an insulating film is formed on the semiconductor region, a defect site serving as a carrier trap exists in the surface layer of the semiconductor region, so that the rate of change in the reflectance of the measurement light decreases. Therefore, the progress of the etching can be quickly and reliably determined by the magnitude of the change rate of the reflectance of the measurement light.

[0211] As set forth in claim 114, in the step of calculating the change rate of the reflectance, the change rate of the reflectance of the measurement light in the wavelength range of 600 nm or less may be calculated. preferable.

[0212] As set forth in claim 115, in the step of calculating the change rate of the reflectance, the change rate of the reflectance of the measurement light in the wavelength range of 300 to 600 nm is calculated. Is more preferred.

According to this method, the measurement light in the wavelength region shorter than the visible light is used. Therefore, in particular, the region where light enters the semiconductor region can be made shallower, and the deterioration of sensitivity due to internal information can be avoided. It becomes possible.

[0214] As described in Item 116, in the step 113, the step of calculating the change rate of the reflectivity may include the step of calculating the change rate of the reflectivity of the measurement light. The change rate of the reflectance of the measurement light at the specific energy value can be calculated.

According to this method, the state of formation of the insulating film can be easily, quickly, and accurately controlled while utilizing the characteristic shape of the spectrum indicating the degree of change in the rate of change of the reflectance depending on the wavelength of the measuring light. Can be.

As set forth in claim 117, in claim 116, it is preferable that the specific energy value of the measuring light be any value within a range of 3.2 to 3.6 eV.

As set forth in claim 118, in any one of claims 113 to 117, in the step of irradiating the excitation light, the excitation light is supplied at 1 kHz.
It is preferable to irradiate intermittently at the following frequencies.

[0218] As described in Item 119, in any one of Items 113 to 118, the change rate of the reflectance of the measurement light when the removal of the insulating film is properly completed in advance can be adjusted. A range is determined, and in the fourth step, the dry etching of the insulating film can be performed so that the change rate of the reflectance of the measurement light evaluated in the second step falls within the appropriate range.

According to this method, the variation in the formation state of the damaged layer in the semiconductor region between lots can be reduced as much as possible.

[0220] As described in Item 120, in any one of Items 113 to 118, in the second step, the reflection of the measurement light on the semiconductor region when the insulating film is formed is provided. In the fourth step, the rate of change of the reflectance of the measurement light in the semiconductor region, which changes with the progress of the removal of the insulating film, is re-evaluated. By comparing the result with the evaluation result in the second step, the condition for removing the insulating film can be controlled.

According to this method, it is easy to suppress the damage layer in the semiconductor region as small as possible.

[0222] As described in Item 121, in any one of Items 112 to 120, in the first step, the first semiconductor, which is a part of a semiconductor element, is used as the semiconductor region. Forming a region and a second semiconductor region for performing an optical evaluation; in the second step, evaluating the optical characteristics of the second semiconductor region; in the third step, the first semiconductor region; And the second semiconductor region are simultaneously etched, and in the fourth step,
The conditions for the etching process can be controlled based on the evaluation results of the optical characteristics in the second semiconductor region.

According to this method, without affecting the characteristics of the first semiconductor region where the semiconductor element is actually formed,
Since the size, impurity concentration, and the like of the second semiconductor region for performing the optical evaluation can be set to a state suitable for the optical evaluation, more accurate optical evaluation can be performed.

[0224] As described in Item 122, in Item 121, in the first step, the impurity concentration in the second semiconductor region is higher than the impurity concentration in the first semiconductor region. can do.

[0225] As described in Item 123, in any one of Items 112 to 122, in the first step, a portion for performing optical evaluation in the semiconductor region is an n-type portion. It is preferred to be made of silicon.

As described in Item 124, in any one of Items 112 to 123, it is preferable that in the first step, a silicon oxide film is formed as the insulating film.

[0227] As described in Item 125, in any one of Items 112 to 124, in the first step, a gate insulating film can be formed as the insulating film.

According to this method, control for minimizing the damage layer in the semiconductor region serving as the source / drain region, which greatly affects the performance of the FET, becomes possible.

[0229] As described in Item 126, in Item 125, in the first step, a conductor film for a gate electrode is formed on the gate insulating film, and in the third step, the conductive film for a gate electrode is formed. The conductor film for the gate electrode can be patterned, and subsequently, the gate insulating film can be patterned.

According to the method of claim 125 or 126,
It is possible to control the removal of the insulating film so as to minimize the damage layer in the semiconductor region serving as the source / drain region that greatly affects the performance of the FET.

As set forth in claim 127, in any one of claims 113 to 120, in the second step, the change ratio of the reflectance of the measurement light using an ellipsometry spectrometer is used. Can be evaluated.

According to this method, an insulating film is removed based on an in-line optical evaluation using an ellipsometry spectrometer which is often attached to a semiconductor device manufacturing apparatus for measuring the thickness of an oxide film. Can be controlled.

According to the present invention, there is provided a method for managing a semiconductor device manufacturing apparatus, comprising: a chamber for accommodating a substrate having a semiconductor region; and processing the substrate in the chamber. Processing means for applying, a first light supply means for intermittently irradiating excitation light to a semiconductor region of the substrate provided in the chamber, and a first light supply means for irradiating measurement light to the semiconductor region. A method for managing an apparatus for manufacturing a semiconductor device, comprising: a second light supply unit; and a reflectance detection unit configured to detect a reflectance of measurement light applied to the semiconductor region. A first step of irradiating, a second step of intermittently irradiating the semiconductor region with the excitation light, and a measurement of when the semiconductor region is irradiated with the excitation light and when the excitation light is not irradiated. A third step of calculating a value obtained by dividing the difference in reflectance of the measurement light by the reflectance of the measurement light when the excitation light is not irradiated, as a change rate of the reflectance of the measurement light, and the third step. A fourth step of controlling the processing means to operate for a predetermined time until the change ratio of the obtained reflectance reaches a predetermined value, and monitoring the predetermined time in the fourth step. A fifth step of outputting a signal for performing maintenance of the semiconductor device manufacturing apparatus when the predetermined time exceeds the limit value.

According to this method, as the semiconductor device manufacturing apparatus is used, it is monitored that the processing time until the change rate of the reflectance reaches a predetermined value due to deterioration of the constituent members in the chamber increases. Can be. Therefore, when the constituent members in the chamber are deteriorated, maintenance can be performed at appropriate timing and without waste. By performing the maintenance, an appropriate processing time can be secured, and the occurrence of a defect in the semiconductor region due to an excessive processing time can be avoided. As described in claim 129, in claim 128, the processing means can generate plasma in the chamber to etch the semiconductor region.

According to this method, while performing plasma etching in the chamber, for example, when the detection sensitivity of the change rate of the reflectance of the measurement light is deteriorated due to a deposit on the wall surface of the chamber generated during the plasma processing. Then, maintenance of the chamber and the like can be performed to maintain proper control.

[0236] As described in Item 130, in Item 128, the processing means is a dry processing device for generating plasma in the chamber to remove a damaged layer generated by etching the semiconductor region. Etching may be performed.

According to this method, while performing dry etching for removing a damaged layer caused by etching, for example, the detection sensitivity of the change ratio of the reflectance of the measurement light by the deposit on the wall surface of the chamber generated during plasma processing. When deterioration occurs, maintenance of the chamber and the like can be performed, and appropriate control can be maintained.

As set forth in claim 131, in claim 128, the processing means can introduce impurities into the semiconductor region.

According to this method, for example, when the detection sensitivity of the change rate of the reflectance of the measurement light is deteriorated due to a deposit on the wall surface of the chamber or the like generated during the impurity introduction process while the impurity introduction process is being performed. , And maintenance of the chamber and the like can be performed to maintain proper control.

As set forth in claim 132, in claim 128, the processing means can perform annealing after ion implantation into the semiconductor region.

According to this method, while performing annealing for recovering the disorder of the structure caused by the ion implantation, when the members of the chamber are deteriorated due to the annealing performed at a high temperature, the maintenance of the chamber and the like is performed. To maintain proper control.

As set forth in claim 133, in claim 128, the processing means can form a thin insulating film on the semiconductor region.

According to this method, while the insulating film is formed by thermal oxidation, CVD, or the like, the detection sensitivity of the change rate of the reflectance of the measurement light is deteriorated due to deterioration of the members in the chamber caused by, for example, thermal oxidation. In such a case, maintenance of the chamber and the like can be performed to maintain proper control.

[0244] In Claim 128, when a thin insulating film is formed on the semiconductor region, the processing means is replaced by a thin insulating film on the semiconductor region. May be performed by dry etching.

According to this method, while performing dry etching for removing a damaged layer caused by etching, for example, the detection sensitivity of the change ratio of the reflectance of the measurement light due to a deposit on the wall surface of the chamber generated during plasma processing. When deterioration occurs, maintenance of the chamber and the like can be performed, and appropriate control can be maintained.

[0246] As described in Item 135, in any one of Items 128 to 134, the reflectance detecting means may detect the reflectance of the measurement light in a wavelength range of 600 nm or less. preferable.

[0247] As described in Item 136, in Item 135, the reflectance detecting means may be 300 to 300.
More preferably, the reflectance of the measurement light in the wavelength range of 600 nm is detected.

[0248] As described in Item 137, in any one of Items 128 to 136, the step of calculating the change rate of the reflectivity includes the step of calculating the spectrum of the change rate of the reflectivity of the measurement light. The change rate of the reflectance of the measurement light at the specific energy value of the measurement light that gives an almost extreme value can be calculated.

[0249] As described in Item 138, in any one of Items 128 to 137, the reflectance detecting means detects the reflectance of reflected light of a specific wavelength using an optical filter. It is preferable to configure so that

As described in Item 139, in any one of Items 128 to 138, it is preferable that the semiconductor region is made of n-type silicon.

As set forth in claim 140, in any one of claims 128 to 139, in the step of irradiating the excitation light, the excitation light is supplied at 1 kHz.
It is preferable to irradiate intermittently at the following frequencies.

A semiconductor device according to the present invention is provided on a substrate and the substrate,
The semiconductor device includes a first semiconductor region serving as a part of a semiconductor element formed on a substrate, and a second semiconductor region for monitoring optical characteristics of the first semiconductor region during processing.

Thus, when various processes are performed on a semiconductor wafer, the state of the first semiconductor region, which changes in accordance with the progress of the processing in the first semiconductor region, is changed by utilizing the optical characteristics of the second semiconductor region. Can be monitored
A semiconductor device having a configuration capable of appropriately determining processing conditions, processing time, and the like in processing in a wide field can be obtained.

The second semiconductor region according to claim 141 may be provided in a region different from the region where the semiconductor chip including the semiconductor element is formed, as described in claim 142. As described in 143, it may be provided in a region where a semiconductor chip including the semiconductor element is formed.

[0255] As described in Item 144, in any one of Items 141 to 143, the second semiconductor region is formed of a semiconductor material for monitoring by light modulation reflectance spectroscopy. Area.

As described in Item 145, in any one of Items 141 to 144, it is preferable that the second semiconductor region is made of n-type silicon.

[0257]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a first embodiment of the present invention will be described.

FIG. 4 shows the reflection intensity R according to the first embodiment.
FIG. 3 is a cross-sectional view schematically showing a configuration of an etching apparatus provided with the observation means of FIG. As shown in FIG.
Inside, an anode electrode 213 as a lower electrode and a cathode electrode 214 as an upper electrode are disposed, and a wafer 103 made of p-type silicon as a workpiece is set on the anode electrode 213. I have. Then, when high-frequency power is supplied between the electrodes 213 and 214 from the high-frequency power supply 211 via the coupling capacitor 212, the plasma 401 is generated in the reaction processing chamber 200. In addition, on the wall surface of the reaction processing chamber 200,
An end point detection window 215, a probe light incidence window 218,
A reflected light observation window 219 is provided.

On the other hand, an end point detection system 216 is provided outside the reaction processing chamber 200, and a member for observing the reflection intensity R is provided. First, Xe which generates probe light for irradiating the n-type semiconductor region 101
A lamp 302 is provided. The probe light 403 generated by the Xe lamp 302 is reflected by a mirror 217 and then n-type of the wafer 103 installed in the reaction processing chamber 200 via a probe light incident window 218. Semiconductor region 1
01 is sent. Then, the reflected probe light 404 reflected by the n-type semiconductor region 101 is reflected by the reflected light observation window 219.
From the reaction processing chamber 200, and the intensity (in particular, the wavelength 376 n
m, the energy is around 3.3 eV). The data on the reflection intensity measured by the reflection intensity observation system 220 is sent to the etching control system 222 via the signal path 221. Further, the n-type semiconductor region 1
Ar ion laser 3 that generates excitation light to irradiate 01
01 is provided, and this Ar ion laser 301 is provided.
The excitation light 402 generated in the above is chopped by the chopper 223 at a frequency of 200 Hz, and is intermittently transmitted. The excitation light 402 is sent into the reaction processing chamber 200 via the end point detection window 215, and is applied to the n-type semiconductor region 101 intermittently. Then, as described above, the excitation light 4
02 when the probe light 403 is irradiated and when the probe light 403 is not irradiated (that is, when the reflected probe light 40
4) is divided by the reflection intensity R when the excitation light 402 is not irradiated (ΔR / R) and detected by the reflection intensity observation system 220 as a change ratio of the reflection intensity. With the above configuration, the change in the change rate of the reflection intensity is monitored. In general, in the optical system according to the present embodiment and each of the following embodiments, a polarizer is often arranged on the incident side of the probe light and an analyzer is arranged on the reflection side in many cases.

Here, it is considered that such a change ratio of the reflection intensity (ΔR / R) is caused by the following action. In general, when a semiconductor is irradiated with light, the semiconductor is excited by the light to increase the number of carriers, and then emits and disappears when the carriers return to the original energy level. The electric field intensity changes with the change in the number of carriers. Therefore, the reflection intensity differs between when the excitation light is irradiated and when the excitation light is not irradiated. However,
When there are many defects in a semiconductor, an interface state having a low energy level exists due to the defect. Since defects having such an interface level function as a carrier trapping layer, even when irradiated with light, carriers are trapped by the defects and are not excited to a sufficiently high energy level, or a high energy level is not excited. If carriers excited to the level are captured by defects, the intensity of light generated when the carriers are excited and return to a low energy level decreases, and the electric field intensity also changes. Therefore,
As the depth of the damage layer and the degree of damage increase, the change ratio (ΔR / R) of the reflection intensity decreases. Therefore,
By monitoring the rate of change of the reflection intensity, information on the damaged layer can be obtained.

The frequency of the chopping is considered to be related to the time when the electric field strength changes due to the recombination of the carriers. From experiments, it has been found that the frequency is preferably 1 kHz or less, more preferably 500 Hz or less. I have. Further, it is preferable that the energy of the photon of the excitation light be larger than the band gap of the semiconductor region. When a silicon substrate is used, it is preferable to use excitation light having a wavelength of photon energy of 1.1 eV or more. The above is the same in each embodiment described later.

In the present embodiment, since the irradiation intensity of the measurement light (in each wavelength range) is assumed to be constant, the detection of the reflection intensity is replaced by the detection of the reflectance. That is, the measurement of the change ratio of the reflection intensity is performed by using the n-type semiconductor region 10.
1 is intermittently irradiated with an excitation light 402 as an Ar ion laser light, and is continuously irradiated with a probe light 403 as a Xe lamp light from another direction.
3 is performed by detecting a change in the reflection intensity. That is, n
The difference ΔR between the reflection intensity when the excitation light 402 is applied to the n-type semiconductor region 101 and the reflection intensity when the excitation light 402 is not applied to the n-type semiconductor region 101 is not irradiated with the excitation light 402 The value (ΔR / R) divided by the reflection intensity R at that time is defined as the difference in reflection intensity, that is, the reflectance.

Here, the wavelength of the probe light is changed while the irradiation and non-irradiation of the excitation light are repeated, the rate of change of the reflectance is measured for each wavelength (light energy value), and the spectrum shape is examined. This is called light modulation reflectance spectroscopy. For example, FIG. 22 is a spectrum diagram showing the relationship between the energy value proportional to the reciprocal of the wavelength λ of the probe light incident on the single crystal silicon layer which is the semiconductor region and the rate of change in reflectance (ΔR / R). . However, the value of the change ratio (ΔR / R) of the reflectance in FIG. 6 is a relative value with the initial state being 0. In the present embodiment, the wavelength 376 nm of the probe light corresponding to the energy value 3.30 eV (the energy value showing an extreme value) of the highest sensitivity at which the change rate of the reflectance (ΔR / R) fluctuates is used. I have.

FIG. 3 is a top view schematically showing the structure of a wafer according to this embodiment. As shown in FIG. 3, on a wafer 103 made of p-type silicon, a chip region Rtp which is finally cut out from the wafer and becomes a semiconductor chip is formed.
And a monitor area Rmn for optical evaluation.

Next, the relationship between the progress of the etching process and the measurement of the rate of change in reflection intensity (ΔR / R) in this embodiment will be described with reference to the cross-sectional structure of the wafer. FIG.
4A to 4C are cross-sectional views of a wafer illustrating a manufacturing process of the semiconductor device according to the embodiment. Before the step shown in FIG. 2A, an n-type semiconductor region 101 (having a specific resistance of about 0.02 Ωcm) having a size of, for example, 13 × 13 μm ² is formed in the monitor region Rmn on the wafer 103. . On the other hand, various semiconductor elements are formed in the chip region Rtp. FIG. 2A shows, as an example, a gate electrode 106 made of polysilicon and a thickness of, for example, 6 n.
A MOS transistor having an m gate oxide film 107 and an n-type source region 108 and an n-type drain region 109 is shown. Then, an interlayer insulating film 104 is deposited on the entire surface of the wafer. In the present embodiment, the n-type semiconductor region 101 is doped with the same conductivity type and the same concentration of impurities as those of the n-type source region 108 and the n-type drain region 109.
The semiconductor region in mn may be doped with an impurity having a different conductivity type and a different concentration from those of the source / drain regions in the semiconductor device to be monitored. In particular, by increasing the impurity concentration in the monitor region Rmn, it is possible to further increase the detection sensitivity in the state where the etching damage is removed.

Next, in a step shown in FIG. 2B, a photoresist mask 105 for forming a contact hole is formed on the interlayer insulating film 104, and the interlayer insulating film 104 is selectively formed using the photoresist mask 105. Dry etching is performed for removal. This dry etching is processing using plasma as described later, and the etching conditions are, for example, as follows. Ar
Gas, mixed gas of CHF3 gas and CF4 gas,
The gas flow rate is 80 sccm for Ar gas, 45 sccm for CHF3 gas, and 20 sccm for CF4 gas. The whole gas pressure is 80 mTorr, and high-frequency discharge is performed at a power of 400 W. By this dry etching process, MO
Openings 110a and 110b, which are contact holes that reach the n-type source region 108 and n-type drain region 109 of the S transistor, respectively, are formed at the same time as a monitoring opening 110c that reaches the n-type semiconductor region 101. . Then, each opening 11 is formed by a plasma emission method.
At the time when the completion of the formation of the n-type source region 108 and the n-type drain region 10 on the wafer is detected.
9, the n-type semiconductor region 101 has a damaged layer Rdm1,
Rdm2 and Rdm3 are formed respectively.

Next, in the step shown in FIG. 2C, light etching (dry etching) for removing damaged layers Rdm1 to Rdm3 caused by dry etching.
I do. At this time, in the present embodiment, a condition in which the power is reduced to 200 W is applied without changing the gas flow rate and pressure.

FIG. 1 is a flowchart showing a general procedure of an optical monitor during plasma processing.

First, main etching is performed in step ST100. When the main etching is completed, in step ST101, the initial reflection intensity change rate (ΔR / R) of the n-type semiconductor region 101 is measured. In this embodiment,
N-type semiconductor region 101 after completion of main etching
Of the initial reflection intensity (ΔR /
R).

Next, in step ST102, plasma processing is performed, and in step ST103, the change ratio (ΔR / R) of the reflection intensity during the plasma processing is monitored. In the present embodiment, light etching is performed as plasma processing, and the rate of change (ΔR / R) in reflection intensity during light etching is monitored.

Further, in step ST104, the rate of change of the reflection intensity (ΔR / R) during the plasma processing (light etching in this embodiment) is compared with the rate of change of the initial reflection intensity (ΔR / R), and an experiment is performed in advance. Steps ST102 to ST104 are performed until it is determined that the reference value for judging the completion of the plasma processing is obtained. If it is determined that the plasma processing is ended, the plasma processing is ended in step ST105. I do. In the present embodiment, if it is determined that the removal of the damaged layer has been completed, the light etching ends in step ST105.

Here, the relationship between the change ratio of the reflection intensity and the state of the damaged layer in this embodiment will be described.
FIG. 5 is a diagram showing a temporal change in the ratio of the change rate of the reflection intensity (ΔR / R) to the initial value at a wavelength of 376 nm (energy 3.3 eV). As shown in FIG. 5, immediately after the start of light etching (between 0 and 20 seconds)
Indicates that the change ratio (ΔR / R) of the reflection intensity is larger than when the dry etching in the main step is completed and approaches the initial value, indicating that the damaged layer has been removed. However, as the light etching time increases (after 20 seconds), the change rate of the reflection intensity (ΔR
/ R) to the initial value is smaller than the value at the start of light etching (about 0.6 in the example shown in FIG. 5), and excessive light etching may increase the damage to the Si crystal (substrate). I understand.

On the other hand, as shown in FIG. 6, the correlation between the light etching time and the resistance value of the contact portion (contact resistance) can be obtained by conducting an experiment in advance. As shown in FIG. 6, the contact resistance is large at the initial stage of the light etching. This is because the organic polymer generated by the main etching is deposited near the bottom of the contact hole. Shows that it is gradually removed. As can be seen by comparing FIGS. 6 and 5, there is a correlation between the contact resistance and the rate of change of the reflection intensity (ΔR / R). From this correlation, the standard value of the contact resistance (the cross-sectional dimension of the contact window is 0.6 μm
It can be seen that, in order to obtain 50 ± 5Ω at the time of (1), the rate of change of the reflection intensity (ΔR / R) must be 60% or more of the initial value. Therefore, by terminating the light etching step when the change ratio (ΔR / R) of the reflection intensity reaches 60%, the damage layer generated by the main etching is almost completely removed, and new damage caused by the light etching thereafter is removed. Generation can be suppressed, and a semiconductor device having good junction can be realized.

FIG. 7 shows the contact resistance of a MOS transistor formed by light etching according to the present embodiment, which is performed with optical monitoring for obtaining information on a damaged layer, and a conventional method without such optical monitoring. Is data for comparing with the contact resistance of the MOS transistor formed by the light etching of FIG. As shown in the figure, by using the method for manufacturing a semiconductor manufacturing apparatus of the present embodiment, it is possible to suppress variations in contact resistance as compared with the conventional method, and to manufacture a semiconductor device with high quality and reliability. it can.

Next, advantages obtained by monitoring the damaged layer by light modulation reflectance spectroscopy as in the present embodiment will be described. Generally, the penetration depth of ions when performing the plasma processing is about several tens of nm. Here, since the penetration depth of microwaves such as infrared rays into the semiconductor substrate is 1 μm or more, the information obtained from the reflectance includes not only information from the damaged layer but also a large amount of information from a region other than the damaged layer. It is difficult to accurately extract information on only the damaged layer. Therefore, these methods are not suitable as a method for detecting a minute area such as etching damage. On the other hand, when performing an optical monitor using light in a region below visible light, the depth of penetration into the semiconductor substrate is at most several tens.
Since it is about 0 nm, the detection sensitivity for a damaged layer having a depth of several tens of nm is extremely high. In addition, by irradiating the surface of the etched semiconductor wafer with light, it is possible to directly obtain information on the damaged layer. Thus, by performing such an optical monitor using light in a region below visible light, , Can provide very useful information for in-line evaluation and process control. From this viewpoint, in the light modulation reflectance measurement method in the present embodiment and each of the embodiments described below, by selecting the light source of the measurement light, or by attaching a filter,
It is preferable to detect the measurement light in the wavelength range of 600 nm or less, and it is more preferable to detect the measurement light in the wavelength range of 300 to 600 nm.

In the present embodiment, the monitoring region Rmn is provided in the wafer 103 separately from the chip region Rtp. However, the present invention is not limited to this embodiment, and the monitoring region Rmn is not limited to the chip region Rtp. Even if an optical evaluation pattern is provided, the same effect as in the present embodiment can be obtained.

Further, by managing the amount of change in the change ratio (ΔR / R) of the reflection intensity due to the light etching process within a certain period of time, it is possible to quickly grasp the abnormality of the device and prevent the trouble of the device.

In the above embodiment, the etching process is dry etching using plasma. However, the present invention is not limited to this embodiment. For example, dry etching without using plasma by sputtering or the like, or wet etching is used. And so on.

The present invention is applicable not only to etching for removing a semiconductor region having a large damaged layer at the beginning but also to etching for a semiconductor region having almost no damaged layer. it can.

Further, in the above embodiment, the chip region R
Although the source / drain regions 108 and 109 which are the first semiconductor regions within tp and the n-type semiconductor region 101 within the monitoring region Rmn which is the second semiconductor region have the same impurity concentration and the same depth, The invention is not limited to such an embodiment, and the first semiconductor region and the second semiconductor region may have different impurity concentrations and different impurity conductivity types. This is because if an experiment is performed in advance, the optical characteristics (contact resistance in the above embodiment) in the second semiconductor region for obtaining an appropriate contact resistance in the first semiconductor region can be found. For example, it is possible to make the impurity concentration in the monitor region Rmn particularly high so as to increase the detection sensitivity of the change ratio of the reflection intensity.

In the present embodiment, as shown in FIG. 4, the angle of the probe light 403 with respect to the substrate surface is smaller than the angle of the excitation light 402, Increasing the angle is preferable for reducing the area of the second semiconductor region to be monitored.

(Second Embodiment) FIG. 8 shows an optical monitor system according to the present embodiment. As shown in the figure, an Xe lamp 502 for generating a probe light as a measurement light for irradiating the n-type semiconductor region 101 is provided, and a probe light 507 generated by the Xe lamp 502 is reflected by a mirror 506. Thereafter, the wafer is sent to the n-type semiconductor region 101 on the wafer 103 set on the wafer stage 504. Then, the n-type semiconductor region 101
The reflected probe light 508 is transmitted to the microscope system 505 after passing through the mirror 506, and its intensity (particularly, the wavelength 37) is observed by the observation and analysis system 509.
(Around 6 nm) is detected. In the present embodiment, the irradiation of the probe light 507 to the observation area and the extraction of the reflected probe light 508 are performed by the microscope system 505 and the mirror 5.
By using in combination with 06, it can be performed from a direction perpendicular to the surface of the sample. This is a main point different from the first embodiment. The diameter of the probe light 507 is
The aperture can be reduced to 10 μmφ by the lens 510.
The data on the reflection intensity measured by the observation / analysis system 509 is sent to an etching control system (not shown) via a signal line.

An Ar ion laser 503 of 5 W intensity for generating excitation light for irradiating the n-type semiconductor region 101 is provided. The excitation light 511 generated by the Ar ion laser
N-type semiconductor region 101
Irradiated intermittently. Then, as described above, the reflection intensity of the probe light 507 when the excitation light 511 is irradiated and when it is not irradiated (that is, the reflection probe light 5
A value (ΔR / R) obtained by dividing the difference ΔR of the intensity (08 intensity) by the reflection intensity R when the excitation light 511 is not irradiated is detected by the observation / analysis system 509 as a change ratio of the reflection intensity. With the above configuration, the change in the change rate of the reflection intensity of the probe light is monitored. Note that the semiconductor region 101
A reflection excitation light observation system 513 for detecting the intensity of the reflection excitation light 512 from
The information on the intensity of No. 12 is sent to the observation and analysis system 509 via a signal line. In addition, chopper 5
10 and a detector for detecting the intensity of the reflected light are configured to operate in synchronization.

[0284] Also in this embodiment, the first
As shown in FIG. 3, as shown in FIG. 3, on a wafer 103 made of p-type silicon, a chip region Rtp finally cut out from the wafer to become a semiconductor chip, and a monitor region for optical evaluation Rmn.

Next, the plasma etching method according to the present embodiment will be described with reference to FIGS. 9 (a) to 9 (c).

Before the step shown in FIG.
3, the monitor area Rmn has a size of, for example, 13
× 13 μm ² n-type semiconductor region (resistivity of about 0.02
Ωcm) 101 is formed. On the other hand, the chip region R
At tp, various semiconductor elements are formed.
3A shows, as an example, a gate electrode 106 made of polysilicon and a gate oxide film 1 having a thickness of, for example, 6 nm.
07, the n-type source region 108 and the n-type drain region 1
9 is shown. An interlayer insulating film 104 is deposited on almost the entire surface of the wafer. In this embodiment, the n-type semiconductor region 10
1 denotes an n-type source region 108 and an n-type drain region 10
9 is doped with the same conductivity type and the same concentration of impurities. As described later, the semiconductor region in the monitoring region Rmn has a conductivity type different from that of the source / drain region in the monitored semiconductor element. Impurities having different concentrations may be doped.

Next, in a step shown in FIG. 9B, a photoresist mask 105 for forming a contact hole is formed on the interlayer insulating film 104, and the interlayer insulating film 104 is selectively formed using the photoresist mask 105. Dry etching is performed for removal. This dry etching is etching using plasma, and the etching condition is, for example, A A in a chamber (not shown).
r gas, a mixed gas of CHF3 gas and CF4 gas
The flow rate of the r gas is 80 sccm and the flow rate of the CHF3 gas is 4
High-frequency discharge is performed at a power of 400 W at a flow rate of 5 sccm, a flow rate of CF4 gas of 20 sccm, and an overall gas pressure of 80 mTorr. By this dry etching process,
Openings 110a and 110b, which are contact holes reaching the n-type source region 108 and the n-type drain region 109 of the MOS transistor, respectively, are formed at the same time as n
Opening 110 for monitoring reaching semiconductor region 101
c is formed. When the completion of the formation of each of the openings 110a to 110c by the plasma emission method is detected, the damage layers Rdm1 and Rdm1 are provided in the n-type source region 108, the n-type drain region 109 and the n-type semiconductor region 101 on the wafer 103. Rdm2 and Rdm3 are formed respectively.

Next, in the step shown in FIG. 9C, light etching (dry etching) for removing the damaged layers Rdm1 to Rdm3 caused by dry etching.
I do. At this time, in the present embodiment, a condition in which the power is reduced to 200 W is applied without changing the gas flow rate and pressure.

FIG. 10 shows data obtained by measuring the change ratio of the reflection intensity of the probe light when the intensity of the irradiation excitation light is changed for the sample subjected to the plasma treatment and the sample not subjected to the plasma treatment. As can be seen from the data shown in the figure, the value of the change (ΔR / R) in the reflection intensity of the probe light of the sample subjected to the plasma treatment is smaller than that of the sample not subjected to the plasma treatment.

Therefore, in this embodiment, similarly to the first embodiment, light etching is performed by a desired amount using light modulation reflectance spectroscopy, and the source / drain made of a low-resistance semiconductor region is formed. For example, formation of a region can be performed.

In particular, as in the present embodiment, the probe light 5
07 is incident on the surface of the wafer in a perpendicular direction and the reflection intensity is detected, compared to the case where the probe light is incident on the surface of the substrate in a direction inclined to the surface of the wafer, Since the evaluation of the damaged layer can be easily performed, there is an advantage that a useless space such as the monitor region Rmn can be reduced.

When the probe light 507 is incident from the vertical direction, the reflection intensity increases, that is, the detection sensitivity increases. That is, in order to actually perform high-accuracy measurement, it is necessary to integrate data obtained by repeatedly performing chopping at one measurement point in order to increase the S / N ratio. However, when the probe light 507 is incident from the vertical direction, a high S / N ratio can be obtained by one measurement per chopping, so that the number of times of chopping is reduced and the evaluation time is shortened. Specifically, for example, when the light is incident on the surface of the wafer in a vertical direction, 45
° Evaluation time is 1 compared to the case of incidence from an inclined direction.
The evaluation time can be greatly reduced in 15 to 3 minutes per sheet. When evaluating a damaged layer in etching in-line, it can be said that the merit of shortening the evaluation time is extremely large.

In the present embodiment, the monitoring region Rmn is provided in the wafer 103 separately from the chip region Rtp. However, the present invention is not limited to this embodiment, and the present invention is not limited to this. Even if an optical evaluation pattern is provided, the same effect as in the present embodiment can be obtained. further,
When irradiating the surface of the substrate with probe light from a vertical direction, it is possible to directly observe the contact window without separately providing an optical evaluation pattern.

Further, by managing the amount of change in the change ratio (ΔR / R) of the reflection intensity due to the light etching process within a certain period of time, abnormality of the device can be quickly grasped, and trouble of the device can be prevented.

In the first and second embodiments, the etching process is dry etching using plasma.
The present invention is not limited to this embodiment, and can be applied to, for example, dry etching without using plasma by sputtering or the like, or wet etching.

Further, in the first and second embodiments, not only the etching for removing the damaged region from the semiconductor region where the large damaged layer is initially formed, but also the semiconductor region having almost no damaged layer is etched. It can also be applied to etching when going. Furthermore, detection of the film thickness when forming or removing the silicon oxide film, detection of the degree of recovery of the crystallinity during the annealing process of the semiconductor substrate, etc.
The optical evaluation method of the present invention can also be used to obtain information on the structure of a semiconductor region widely.

In the first and second embodiments, the source / drain regions 108 and 109 which are the first semiconductor regions in the chip region Rtp and the n-type regions in the monitor region Rmn which is the second semiconductor region are provided. Although the impurity concentration and the depth of the semiconductor region 101 are the same, the present invention is not limited to this embodiment, and the first semiconductor region and the second
The semiconductor regions may have different impurity concentrations or different impurity conductivity types. This is because if an experiment is performed in advance, the optical characteristics (contact resistance in the above embodiment) in the second semiconductor region for obtaining an appropriate contact resistance in the first semiconductor region can be found. For example, it is possible to make the impurity concentration in the monitor region Rmn particularly high so as to increase the detection sensitivity of the change ratio of the reflection intensity.

(Third Embodiment) In this embodiment, an embodiment of an optical monitor system will be described. The method for processing the semiconductor device can be performed in the same manner as in the first and second embodiments and the noted deformable modes.

FIG. 11 is a perspective view showing an optical evaluation device according to the present embodiment. 8, the same components as those shown in FIG. 8 are denoted by the same reference numerals. That is, similarly to the second embodiment, the wafer stage 5
04, a Xe lamp 502, a mirror 506, an Ar ion laser 503, a chopper 510, and an observation / analysis system 509. And
The feature of this embodiment is that the excitation light 511 and the probe light 507
523 for coaxially guiding the wafer 1 and the wafer 1
The spectroscope 5 for dispersing the reflected light 518 in which the excitation light and the probe light reflected from the n-type semiconductor region 03 are mixed.
21 and a detector 522 for detecting the intensity of light at each wavelength separated by the spectroscope 521. Xe lamp 502, mirrors 506 and 52
3. An optical system 530 includes an Ar ion laser 503, a chopper 510, and a spectroscope 521.

In the optical evaluation device of this embodiment,
A probe light 507 generated by the Xe lamp 502 and A
The excitation light 511 generated by the r ion laser 503 is guided coaxially by the mirror 523 and
After being reflected together by the laser beam 6, it is sent to the n-type semiconductor region 101 on the wafer 103 set on the wafer stage 504. The reflected light 518 in which the reflected probe light and the reflected excitation light reflected by the n-type semiconductor region are mixed passes through the mirror 506 and is sent to the spectroscope 521, where the light is detected.
After the intensity is detected by 22, the change in the intensity is analyzed by the observation and analysis system 509.

Therefore, by using the optical evaluation apparatus of the present embodiment, it is possible to evaluate the sample subjected to the plasma processing by the same method as the method described in the second embodiment. In addition, the present embodiment is configured such that the probe light and the excitation light are guided to a common optical axis and then incident on the n-type semiconductor region on the wafer 103 which is the observation point. Alignment can be performed very easily, and the configuration of the apparatus can be simplified.

Further, according to the structure of the present embodiment, the evaluation of the Si damage layer in a finer semiconductor region can be easily performed as compared with the method shown in the second embodiment. In addition, since the excitation light is also incident from the vertical direction, the beam diameter can be reduced to about 30 μm, and the sample evaluation should be performed at a smaller observation point than when the excitation light is incident from a direction inclined at 45 °. Can be. In addition, the evaluation time can be reduced to about 20% of the second embodiment.

Therefore, even if a monitor area is not separately provided in the wafer, if there is a wide semiconductor area in the LSI of the wafer, it is possible to measure the damage of plasma processing or the like by using the wide semiconductor area.

(Fourth Embodiment) FIG. 12 is a perspective view showing an optical evaluation device according to a fourth embodiment. In the figure, the same components as those shown in FIG. 11 are denoted by the same reference numerals. That is, similarly to the third embodiment, the wafer stage 504 and the Xe lamp 502
, Mirrors 506 and 523, and Ar ion laser 5
03, a chopper 510, and an observation / analysis system 509 are provided. The present embodiment is characterized in that a filter 525 for passing light in a specific wavelength range among reflected light 518 in which probe light and excitation light reflected from the n-type semiconductor region of the wafer 103 are mixed.
(The peak wavelength is 350 nm) and this filter 525
And a detector 524 for detecting the intensity of light that has passed through. Xe lamp 502, mirror 5
06 and 523, an Ar ion laser 503, a chopper 510, and a filter 525 to form an optical system 53.
0 is configured.

In the optical evaluation apparatus of this embodiment, unlike the method of each of the above embodiments, it is possible to observe the change ratio of the reflection intensity in a specific wavelength range of the probe light without spectroscopy. With this method, the time required for evaluation can be reduced to the order of several seconds.

FIG. 13 shows the change ratio (ΔR / R) of the reflection intensity of the probe light after performing light etching for 20 seconds using the optical evaluation apparatus of the present embodiment.
FIG. 9 is a diagram showing a measurement result obtained by changing a bias power. In this case, instead of spectrally analyzing the reflected probe light and analyzing the spectrum, the detector 524 filters the filter 5.
Since the light transmitted through 25 was observed, the result shown in FIG.
It is considered that the intensity of the light of nm was integrated and detected. FIG. 13 shows that as the plasma intensity increases, the rate of change (ΔR / R) in the reflection intensity of the probe light decreases, so that the damage in the processing region increases. That is, also in the method of the present embodiment, it was possible to clearly detect the difference in the change rate of the reflectance of the measurement light due to the difference in the processing degree of the plasma processing. In the present embodiment, as described above, since the spectrum analysis is not necessary, the evaluation time can be reduced to the order of several seconds.

(Fifth Embodiment) FIG. 14 is a perspective view showing an optical evaluation device according to a fifth embodiment. In the figure, the same components as those in FIG. 11 are denoted by the same reference numerals. That is, similarly to the third embodiment, the wafer stage 504, the Xe lamp 502, and the chopper 51
0, a spectroscope 521, and a detector 522. The feature of this embodiment is that the optical system 530
The light generated by the Xe lamp 502 is
Beam splitter 52 for separating light into light 7 and excitation light 511
6 and a mirror 527 for reflecting the excitation light 511
And a mirror 528 that reflects the probe light 507 and transmits the reflected light 518 from the wafer 103, and transmits the probe light 507 and reflects the excitation light 511 to guide both to the wafer and transmit the reflected light. The point is that a combination mirror 529 is provided. The Xe lamp 502, the chopper 521, the beam splitter 526,
The mirrors 527 and 528, the combination mirror 529, and the spectroscope 521 constitute an optical system 530.

That is, in the present embodiment, unlike the above embodiments, the light from the Xe lamp 502, which is one light source, is separated into the probe light 507 and the excitation light 511. The same light modulation reflectance spectroscopy is performed. Therefore, according to the present embodiment, the optical system 530 can be made compact as shown in FIG. 14 because only one light source is required, and the cost is reduced and the maintenance efficiency is improved because there is no need to use a laser. Can be achieved.

FIG. 15 shows the change ratio (ΔR / R) of the reflection intensity of the probe light after performing the light etching for 20 seconds using the optical evaluation apparatus of the present embodiment.
FIG. 9 is a diagram showing a measurement result obtained by changing a bias power. FIG. 15 shows that as the plasma intensity increases, the rate of change (ΔR / R) in the reflection intensity of the probe light decreases, so that the damage in the processing region increases. That is, also in the method of the present embodiment, it is possible to clearly detect the difference in the change in the reflectance of the measurement light due to the difference in the processing degree of the plasma processing.

FIG. 16 shows a temporal change in the ratio of the change rate (ΔR / R) of the reflection intensity of the probe light to the initial value at a wavelength of 376 nm (energy 3.3 eV) using the optical evaluation apparatus of this embodiment. It is a figure which shows the result of having measured. As shown in the figure, the change in the change rate (ΔR / R) of the reflection intensity of the probe light accompanying the progress of the light etching is basically almost the same as the change shown in FIG. However, in the present embodiment, the change ratio of the reflection intensity (ΔR /
The value of R) itself is larger than the value shown in FIG. This means that the sensitivity was increased by inputting the excitation light also from above.

(Plasma Processing Apparatus Common to Second to Fifth Embodiments) FIG. 17 is a sectional view schematically showing the structure of a plasma processing apparatus commonly used in the second to fifth embodiments. It is. As shown in the figure, the plasma processing apparatus includes a chamber 200, an RF power supply 211 for supplying high-frequency power for plasma generation, a coupling capacitor 212, and a lower electrode 213 installed at the bottom in the chamber 200. An upper electrode 214 installed on the ceiling of the chamber 200, viewing windows 218 and 219 provided on the side wall of the chamber 200, and an observation window 220 provided near the center of the ceiling of the chamber 200. ing.
However, the wafer stage is not shown in FIG. Then, a plasma region 401 is generated between the upper electrode 214 and the lower electrode 213 by the high-frequency power supplied from the RF power source 211, and the n-type semiconductor region 101 in the wafer 103 placed on the lower electrode 213 is processed. It is configured to be.

In the third to fifth embodiments, as shown in FIG. 17, the optical system 530 can be collectively arranged above the observation window 220 of the chamber 200. However, in the second embodiment, only the optical system for the probe light is arranged above the observation window 220, and the optical system for the excitation light is the viewing windows 218 and 219.
Will be arranged on the side.

With the structure of such a plasma processing apparatus, at least probe light can be incident from a direction perpendicular to the wafer surface. By observing a change in the reflectivity of the probe light, process observation can be performed in real time. It can be achieved. In addition, feedback to processing conditions and the like can be performed using the signal 531 from the optical system.

(Sixth Embodiment) FIG. 18 is a sectional view schematically showing a configuration of a heat treatment apparatus (annealing apparatus) for a semiconductor device according to a sixth embodiment. As shown in FIG. 18, a quartz tube 603 is mounted in a reaction vessel 607, and a wafer 103 is placed on an inner surface of the quartz tube 603 via a wafer susceptor 602. A heater 604 using infrared light is mounted on the outer surface of the quartz tube 603, and the heater 604 is used for the wafer 10 in the quartz tube 603.
3 is heated. The reaction vessel 607 has a reaction gas inlet 609 and a reaction gas outlet 610.
Is provided, and the flow rate of the reaction gas is controlled by a flow controller 60.
8, so that it can be adjusted appropriately. Also,
Two observation quartz windows 60 are provided on the side of the reaction vessel 607.
5,606 are provided facing each other. An n-type semiconductor region 101 (specific resistance value of about 0.02 Ωcm) is provided in a part of the wafer 103, and light incident on the n-type semiconductor region 101 on the wafer 103 from one observation quartz window 605 is provided. It is configured so that it can be taken out from the other observation quartz window 606. Although not shown, a pattern (having a size of 13 × 13 μm ² ) for optical evaluation is provided in the n-type semiconductor region 101 of the wafer 103.

Further, outside the reaction vessel 607, a Xe lamp 611 for generating a probe light 618, which is measurement light, which enters the reaction vessel 607, and an Ar ion laser 612 for generating an excitation light 620 in the reaction vessel 607. (Output 1
W), a chopper 614 for chopping the excitation light 620 at a frequency of 200 Hz, and a reflected probe light 619 reflected from the n-type semiconductor region 101 on the wafer 103.
And a detector 613 for receiving the intensity and detecting the intensity. That is, while the probe light 618 generated by the Xe lamp 611 is irradiated on the n-type semiconductor region 101 on the wafer 103 as the evaluation pattern, the excitation light 620 generated by the Ar ion laser 612 is also chopped by the chopper 614 at a frequency of 200 Hz. Wafer 10
3 is configured to irradiate the n-type semiconductor region 101 on the substrate 3 and monitor a change in reflectance from a change in intensity of the reflected probe light 619 from the n-type semiconductor region 101 due to irradiation / non-irradiation of the excitation light 620. I have. Then, the heater 604 and the chopper 61 are controlled by the control system computer 615.
4 and the operation of the flow controller 608, while detecting the detection signal of the detector 613 and monitoring the optical characteristics of the n-type semiconductor region 101. The chopper 614 and a detector 613 for detecting the intensity of the reflected light
And is configured to operate in synchronization with.

Next, the principle of an optical evaluation method using a change in reflectance will be described.

The rate of change of the reflectance of the measurement light is the difference between the reflectance of the measurement light when the semiconductor region to be evaluated is irradiated with the excitation light and the reflectance when the excitation light is not irradiated. This is a value (ΔR / R) obtained by dividing ΔR by the reflectance R when the semiconductor region is not irradiated with the excitation light. It is considered that such a change in the reflectance of the measurement light is caused by the following operation. In general, when a semiconductor is irradiated with light, the semiconductor is excited by the light to increase the number of carriers, and then emits and disappears when the carriers return to the original energy level. The electric field intensity increases or decreases with the change in the number of carriers. Therefore, the reflection intensity of the measurement light differs between when the excitation light is irradiated and when the excitation light is not irradiated. When the structure of the semiconductor region is in a perfect crystalline state, the rate of change of the reflectance changes depending on the wavelength of the measurement light. In other words, the spectrum in which the change rate of the reflectance of the measurement light is plotted for each wavelength of the measurement light has a characteristic according to the energy gap which is the difference between the bottom of the conduction band and the top of the valence band of the semiconductor constituting the semiconductor region. Characteristic change characteristics.

FIG. 22 shows an example. In other words, the reflectance change rate (ΔR / R) shows a minimum value (extreme value) in the wavelength region where the energy is about 3.3 eV, and the reflectance ratio in the wavelength region where the energy is 3.5 eV. The rate of change (ΔR / R) indicates the maximum value (extreme value). Of the extreme values of the reflectance change rate (ΔR / R), the absolute value of the minimum value is larger than the maximum value.

However, if there are many structural disturbances such as crystallographic defects and electronic structure deviation from a normal state in a semiconductor, a trap level having a low energy level exists in that region. Become. Since a region having a low energy level generated by such a disorder of the structure functions as a carrier trapping layer, the amount of increase in the number of carriers decreases, and the difference in electric field intensity decreases. Therefore, the greater the depth and the degree of the disorder in the region in which the structure in the semiconductor region is disordered due to the implantation of the impurity ions, the smaller the rate of change (ΔR / R) in the reflectivity of the measurement light, and The change in the reflectance of the measurement light due to the irradiation of the excitation light hardly occurs. In other words, in such a case,
A spectrum in which the change ratio of the reflectance of the measurement light is plotted for each wavelength of the measurement light shows only a substantially constant small value.

As described above, by monitoring the rate of change of the reflectance of the measurement light, information on the degree of recovery of the semiconductor region in the annealing process after the implantation of the impurity ions can be obtained.

Next, referring to FIGS. 19 and 20,
The following describes the change over time in the spectrum of the rate of change of the reflectance of the probe light in the annealing process after ion implantation.

FIG. 19 shows an energy value proportional to the reciprocal of the wavelength λ of the probe light and a change ratio of the reflectance (ΔR / R).
FIG. 9 is a spectrum diagram showing the relationship between However, FIG.
Since the horizontal axis is substantially the same as the one in which the wavelength of the measurement light is continuously changed, FIG. 19 shows the spectrum of the change ratio (ΔR / R) of the reflectance with respect to the change of the wavelength. . In this embodiment, since the intensity of the probe light 618 to be irradiated is constant, the irradiation of the excitation light 620
By dividing the intensity difference ΔR of the reflected probe light 619 during non-irradiation by the intensity R of non-irradiation of the excitation light 620,
The change ratio (ΔR / R) of the reflectance is calculated. In addition,
The value of the change ratio (ΔR / R) of the reflectance in FIG. 19 is a relative value with the initial state being 0.

Before the start of the heat treatment step, the dose amount of the n-type semiconductor region 101 on the wafer 103 housed in the reaction vessel 607 is about 1 × 10 ¹⁵ cm in the impurity ion implantation process. ^-2 , arsenic (As) is introduced under the condition that the implantation energy is about 35 keV. A spectrum line S ₀ in FIG. 19 is a spectrum of a change ratio (ΔR / R) of the reflectance immediately after the impurity ions are implanted.

The spectral line S _{10 in} FIG. 19 indicates the rate of change in reflectance (ΔR / R) when the wafer 103 was annealed at 900 ° C. for 10 seconds in an N ₂ gas atmosphere using the apparatus shown in FIG. ) And FIG.
The middle spectral line S ₂₅ is the spectrum of the rate of change in reflectance (ΔR / R) when annealed for 25 seconds under the same conditions. As shown in the figure, it can be seen that the shape of the spectrum of the reflectance change rate (ΔR / R) greatly changes as the annealing process proceeds. In other words, this spectrum shape indicates the recovery of the Si crystallinity due to the annealing treatment. As the recovery progresses, the peak value of the spectral line of the reflectance change ratio (ΔR / R) on the maximum side increases upward and decreases on the minimum side. It can be seen that the peak value of has moved downward.

Therefore, in the present embodiment, attention is paid to the minimum peak value having a larger variation width in the spectrum line, and the degree of recovery in the annealing process after the implantation of impurity ions is monitored by the minimum peak value of the spectrum line. I have. However, as shown in FIG. 19, since the spectral line has a minimum peak value at the point where the energy is about 3.3 eV (wavelength 376 nm), the reflectance of the reflected probe light 619 at a wavelength corresponding to the energy 3.3 eV is obtained. The rate of change is assumed to be the minimum peak value of the spectral line.

FIG. 20 shows the annealing of the wafer 103 using the apparatus shown in FIG. 18 and assuming that the change rate of the reflectance at a wavelength corresponding to the energy of 3.3 eV of the reflected probe light 619 is the minimum peak value of the spectrum line. It is a figure which shows the time-dependent change of the minimum peak value of the spectral line in a process. As shown in the figure, the recovery of the crystallinity of the semiconductor region progresses with the lapse of time of the annealing process.
The minimum peak value increases with time. It is confirmed by Raman spectroscopy that the crystallinity of the semiconductor region (Si crystal in this embodiment) is sufficiently recovered even when the annealing process is completed when the minimum peak value becomes -12.0 (35 seconds). did it.

Therefore, in the present embodiment, the annealing time is not a predetermined time with a certain margin, but
Based on experiments conducted on monitor wafers in advance, realizing device manufacturing with stable crystallinity and a stable impurity profile by controlling the annealing process by changing the minimum peak value in the spectrum line in the actual annealing process it can. That is, during the annealing process, by monitoring the rate of change (ΔR / R) of the reflectance at a specific wavelength (energy region), it is possible to realize a stable annealing process and the manufacture of a device having good characteristics.

Further, in this embodiment, the time required until the minimum peak value becomes -12.0 is managed, and when the time exceeds 40 seconds, the heat treatment apparatus is periodically maintained. FIG. 23 shows a change in annealing time until the minimum peak value of the spectral line becomes -12.0 with respect to the number of processed wafers. The reason why the time required for the minimum peak value to reach -12.0 in accordance with the number of processed wafers is prolonged is considered to be due to deterioration of the components of the apparatus. According to the conventional management method, when annealing for more than 40 seconds is performed, a trouble such as a contact resistance failure in the semiconductor region occurs. However, according to the management method of the present invention, such a trouble occurs. Can be suppressed. That is, by combining the optical management method and the process time management method of the present embodiment, it is possible to realize the process management of the heat treatment process, which was difficult with the conventional method, and thus achieve stable operation. Can be.

Note that in the sixth embodiment, the optical monitor system shown in FIG. 8 in the second embodiment and the optical monitor system shown in FIG. Optical monitoring system,
The optical monitor system shown in FIG. 12 in the fourth embodiment, the optical monitor system shown in FIG. 14 in the fifth embodiment, and the like can be used.

(Seventh Embodiment) Next, a description will be given of a second embodiment relating to a method of measuring an impurity concentration.

In this embodiment, the optical monitor system shown in FIG. 8 used in the second embodiment is used.

However, in the present embodiment, the excitation light 511 is chopped by the chopper 510 at a frequency of 100 Hz, and is applied intermittently to the n-type semiconductor region 103a of the wafer 103. Then, the data regarding the reflection intensity measured by the observation system / analysis system 509 is:
It is sent to a heat treatment control system (not shown) via a signal line. Further, the chopper 510 and the detector for detecting the intensity of the reflected probe light are configured to operate in synchronization.

FIG. 21 shows the relationship between the minimum peak value in the spectral line of the rate of change of the reflectance obtained by actually observing and the dose of the impurity when introducing the impurity. The impurity was arsenic (As), and the dose of the experiment was 1.0.
× 10 ¹⁵ cm ^-2 , 5.0 × 10 ¹⁵ cm ^-2 , 5.0 × 10
¹⁴ cm ⁻² and 1.0 × 10 ¹⁴ cm ⁻² , and in each case, the acceleration energy of the ions is 150 keV. The heat treatment is performed at 850 C for one hour in an N ₂ gas atmosphere. FIG. 22 shows that the dose amount is 1.0 × 10 ¹⁵ c
4 shows a spectrum of a change ratio (ΔR / R) of the reflectance when m ⁻² .

As can be seen from FIG. 21, the minimum peak value of the reflectance change ratio (ΔR / R) of the sample into which the impurities are introduced increases toward the negative side as the dose increases. That is, the change rate of the reflectance (Δ
R / R) reflects the impurity concentration, meaning that the final impurity concentration in the substrate after the heat treatment can be known by monitoring the rate of change of the reflectance (ΔR / R). I have. Therefore, by performing ion implantation of impurities and heat treatment for diffusion until the minimum peak value reaches a certain value, it becomes possible to accurately control the impurity concentration in the n-type semiconductor region 101 to a desired impurity concentration.

In the sixth and seventh embodiments, the heat treatment process for recovering the structural disorder caused by the defects and the like caused by the implantation of the impurity ions has been described. The present invention is not limited to the embodiment, and may be applied to a heat treatment step for recovering a disorder of a structure due to a defect or the like caused by etching.

In the seventh embodiment, the optical monitor system shown in FIG. 9 in the third embodiment or the optical monitor system shown in FIG. 12 in the fourth embodiment is used instead of the optical monitor system shown in FIG. Optical monitoring system,
The optical monitor system shown in FIG. 14 in the fifth embodiment or the like can be used.

(Eighth Embodiment) Hereinafter, FIGS. 24 to 29 will be described.
An optical evaluation device and an evaluation method for a semiconductor device (insulating film) according to the eighth embodiment will be described with reference to FIG.

FIG. 24 is a perspective view schematically showing a configuration of an optical system for monitoring an insulating film according to the present embodiment. In FIG. 24, 701 is a semiconductor substrate in a wafer state on which a silicon oxide film is formed, 702 is a wafer stage, 703 is a Xe lamp as a second light source of 150 W output, 704 is a polarizer, and 705 is provided with an analyzer. Detector,
Reference numeral 706 denotes a probe light (measurement light) which is Xe lamp light;
07 is a reflection probe light, 708 is a signal line for transmitting a signal from the detector 705, and 709 is the first 5 W output.
710, a chopper for modulating the excitation light, 711, an excitation light that is the excitation light modulated by the chopper 710, and 712, a signal for transmitting a synchronization signal with the modulation of the excitation light. Lines 713 indicate control systems, respectively. The detector 705 is configured to measure a continuous spectrum of the intensity of the reflected probe light 707 for each wavelength. The excitation light 711 is supplied to the chopper 710 at a frequency of 500H.
It is configured to be chopped by z and to intermittently irradiate a measurement region of the semiconductor substrate 701 from a direction perpendicular to the surface of the semiconductor substrate 701. Further, the chopper 710 and the detector 705 for detecting the intensity of the reflected light are configured to operate in synchronization.

On the other hand, as shown in FIG. 25, a silicon oxide film 701c is formed on the n-type semiconductor region 701b of the semiconductor substrate 701 as a measured region by, for example, a thermal oxidation method at a temperature of 850 ° C. The probe light 706 passes through the silicon oxide film 701c and is incident on the n-type semiconductor region 701b immediately below the silicon oxide film 701c.
b. Then, the reflection probe light 7
07 is emitted outward through the silicon oxide film 701c.

Although not shown in FIG. 24, for example, a chamber for performing thermal oxidation similar to the structure shown in FIG. 18 is provided, and the wafer stage 702 is set in this chamber. Is provided with a window through which the probe light 706, the reflected probe light 707, and the excitation light 711 pass.

Here, the basic principle of the light modulation reflectance spectroscopy and the method of measuring the change rate (ΔR / R) of the reflection intensity of the reflection probe light 707 according to the present embodiment will be described.

In general, when a semiconductor is irradiated with light, the semiconductor is excited by the light to increase the number of carriers. Thereafter, when the carriers return to the original energy level, the semiconductor emits light and disappears. The surface electric field intensity of the semiconductor region changes with the change in the number of carriers. Therefore, the rate at which the measurement light is reflected on the surface of the semiconductor region, that is, the reflectance of the measurement light, differs between when the excitation light is irradiated and when the excitation light is not irradiated. In other words, if the magnitude of the change in the electric field strength to be caused by the irradiation of the excitation light changes depending on some characteristic of the measurement area, the change rate of the reflectance of the measurement light is measured to measure the change rate of the measurement light. The properties should be able to be evaluated. The present invention is based on such a technique of light modulation reflectance spectroscopy.

Therefore, in the present embodiment, first, while passing through the silicon oxide film 701c of the semiconductor substrate 701, which is the region to be measured, and the n-type semiconductor region 701b immediately thereunder intermittently, the excitation light 711 is intermittently irradiated. , The probe light 706 is continuously passed through the silicon oxide film 701c and irradiated on the n-type semiconductor region 701b immediately therebelow to detect a change in the reflection intensity of the reflected probe light 707. The difference ΔR between the reflection intensity of the reflection probe light 707 when the excitation light 711 is irradiated and the reflection intensity when the excitation light 711 is not irradiated
Is the reflection intensity R when the excitation light 711 is not irradiated.
The value (ΔR / R) divided by is detected by the analysis system 713 as a change ratio of the reflection intensity. Here, the rate of change of the reflection intensity (ΔR / R) is used instead of the reflectance, assuming that the intensity of the probe light 706 to be irradiated is constant, and is technically meaningful. There is a change rate of the reflectance. With the above configuration, the change in the change rate of the reflection intensity of the probe light is monitored. Then, on the display of the analysis system 713 shown in FIG. 24, the change rate (Δ
(R / R) spectrum is displayed.

FIG. 26 shows a spectrum of a change ratio (ΔR / R) of the reflection intensity measured by the detector 705. In the figure, a curve Spa represents a rate of change of the reflection intensity from a semiconductor substrate having a normal silicon oxide film (ΔR /
R), and the curves Spb and Spc show the spectrum of the change ratio (ΔR / R) of the reflection intensity from the semiconductor substrate having the defective silicon oxide film. From the difference in the spectrum shape of the change ratio of the reflection intensity (ΔR / R), the change ratio (ΔR / R
R) falls within a certain range (the area indicated by oblique lines in the figure), whereas the rate of change (ΔR / R) of the reflection intensity from the semiconductor substrate having the defective silicon oxide film is so large that it goes out of this range. I understood that. The cause of such a difference is considered to be due to the following operation.

As shown in FIG. 27A, the excitation light 71 is passed through the silicon oxide film and applied to the n-type semiconductor region immediately below the silicon oxide film.
Irradiation with 1 generates carriers in the n-type semiconductor region, and the surface electric field intensity increases by ΔΦ with the change in the number of carriers. As described above, the change ΔΦ in the surface electric field intensity causes the reflection intensity to be different between when the excitation light is irradiated and when the excitation light is not irradiated.
Here, when a silicon oxide film is formed on the n-type semiconductor region, a defect site serving as a trap of carriers occurs in the surface layer of the n-type semiconductor region, so that the change in the reflectance of the measurement light is small. Should be.

However, as shown in FIG. 27B, when trapped electrons are present in the silicon oxide film, these electrons cause a larger change in surface electric field intensity ΔΦ ′ in the n-type semiconductor region. become. For this reason, the change ratio (ΔR / R) of the reflection intensity from the n-type semiconductor region immediately below the silicon oxide film where many trapped electrons are present depends on the reflection from the n-type semiconductor region directly below the silicon oxide film where few trapped electrons are present. It is considered that the rate of change becomes larger than the rate of change of the intensity (ΔR / R). That is, the spectra Spb, Sb having a large change ratio (ΔR / R) of the reflection intensity as shown in FIG.
Many trapped electrons are present in the silicon oxide film of the semiconductor substrate that gives pc. It is known that such trapped electrons are more present as the number of defects in the silicon oxide film increases. It is also known that when a large number of trapped electrons are present, a carrier path due to dielectric breakdown easily occurs, and the life of the insulating film is short.

To support the above inference, the inventor conducted an experiment in which electrical stress was applied to a silicon oxide film having a thickness of about 2 to 4 nm while changing its magnitude variously, and the results are shown in FIG. Data obtained. FIG. 28 is a diagram showing the relationship between the peak intensity in the spectrum of the rate of change of the reflection intensity (ΔR / R) and the trapped electron density in each oxide film obtained from the measurement of the capacitance by the mercury prober. In the figure, the vertical axis represents the trap electron density (× 10 ¹¹
cm ² ), and the horizontal axis represents the rate of change of the reflection intensity (ΔR /
The relative value of the peak signal intensity giving the minimum peak value around 3.35 eV (corresponding to the wavelength around 375 nm) in the spectrum of R) is taken. As shown in FIG. 28, the trapping electron density increases as the absolute value of the peak signal intensity increases. Therefore, when the absolute value of the change ratio (ΔR / R) of the reflection intensity is larger than a certain range, the silicon oxide film Can be evaluated as having poor quality (that is, many trapped electrons are present).

That is, the change rate of the reflection intensity (ΔR /
If R) (absolute value) is equal to or more than a predetermined value, determining that the gate oxide film is defective depends on the causal relationship obtained empirically, whether or not the above inference is theoretically correct. I do. Therefore, the change rate of the reflection intensity (ΔR /
By monitoring R), the amount of electron traps in the insulating film can be specified, so that the electrical characteristics of the insulating film can be managed optically.

Next, an embodiment in which the process management in the manufacture of a semiconductor device is performed by such an optical evaluation will be described.

As shown in FIG. 29, the peak value in the spectrum of the change ratio (ΔR / R) of the reflection intensity was −0.25 to
If it falls within the range of 0.25 × 10 ^-3 , it is considered a good product.
Conversely, if it does not fall within this range, set it as bad,
Process control was performed when a silicon oxide film was prototyped on a semiconductor substrate (wafer) by thermal oxidation. In FIG. 29,
The horizontal axis indicates the number of processed sheets, and the vertical axis indicates the change rate (ΔR / R) (peak value) of the reflection intensity around 3.35 eV. As a result of monitoring once every 125 sheets, 7
The signal suddenly changed greatly at the 50th sheet. This is a sudden trouble, and the characteristics of the gate oxide film at this time are as follows. When the voltage Vg applied to the gate is -6.6 V, the time tbd (lifetime value) until destruction indicating reliability is 10%.
It was about 0 sec. Normal life value tbd is 10 ⁴ sec
Since it is equal to or longer than c, it can be seen that this life value is abnormally low. In this case, the cause of the trouble can be eliminated by quickly responding to the trouble, and the occurrence of a subsequent failure can be prevented. As described above, according to the present invention, the management of the manufacturing process by the evaluation of the optical characteristics enables quicker response than the management by the conventional evaluation of the electrical characteristics. Deterioration of the yield in the process can be reliably prevented.

It should be noted that an experiment was conducted in advance to determine the appropriate range of the capacity (electrical characteristics) corresponding to the appropriate electron trap density,
The change rate of the reflection intensity corresponding to this appropriate range (ΔR /
If the relationship between R) and the appropriate range is determined, the manufacturing conditions can be controlled so that the change ratio (ΔR / R) of the reflection intensity falls within the appropriate range.

In this embodiment, the optical monitor system shown in FIG. 8 in the second embodiment and the optical monitor system shown in FIG. 9 in the third embodiment are replaced with the optical monitor system shown in FIG. Monitor system, fourth
The optical monitor system shown in FIG. 12 in the embodiment, the optical monitor system shown in FIG. 14 in the fifth embodiment, and the like can be used.

In the optical monitoring system according to the present embodiment, the semiconductor region is irradiated with measurement light having a wavelength of 600 nm or less, more preferably 300 to 600 nm, by selecting a light source of the measurement light or attaching a filter. It is preferable to do so. Light having such a wavelength range has a penetration depth of several tens of nm into the semiconductor region.
Since this is not the case, highly sensitive optical evaluation can be performed based on the difference in the intensity of light reflected from a surface region that is easily affected by trapped electrons in an insulating film such as a silicon oxide film.

(Ninth Embodiment) Next, a ninth embodiment will be described. FIGS. 30A to 30C are cross-sectional views of a wafer showing a step of patterning a gate electrode and a gate oxide film. However, in this embodiment, the gate electrode and the gate oxide film are patterned using the etching apparatus shown in FIG. 4 in the first embodiment.

First, before the step shown in FIG. 30A, a first semiconductor region 800 into which a low-concentration impurity for controlling a threshold value is introduced is formed in a substrate region of a chip region Rtp on a wafer 803. Provided in the first semiconductor region 800
Then, a MOS transistor as a semiconductor element is formed.
On the other hand, in the monitor region Rmn on the wafer 803, a second semiconductor region 801 (having a specific resistance of about 0.02 Ωcm) having a size of, for example, 13 × 13 μm ² and doped with an n-type impurity is formed. On the entire surface of the substrate, a gate oxide film 807 having a thickness of, for example, 6 nm and a gate electrode film 806 made of polysilicon are deposited. further,
On the gate electrode film 806, a photoresist mask 809 having a pattern shape for forming a gate electrode is formed. However, this photoresist mask 809
Also has an opening region above the second semiconductor region 801.

Next, in the step shown in FIG.
The gate electrode film 806 is removed by dry etching (plasma etching) using the photoresist mask 809, and a gate electrode 806a is formed. At this time, the gate electrode film in the second semiconductor region 801 has been removed, and the gate oxide film 807 has been exposed.

Then, in this state, the excitation light 402 and the probe light 403 are irradiated on the second semiconductor region 801 through the gate oxide film 807. However, the excitation light 402 is applied intermittently. Then, as described above, the excitation light 40
The difference (ΔR / R) obtained by dividing the difference ΔR between the reflection intensities of the probe light 403 when irradiation with No. 2 is not irradiated and the reflection intensity R without irradiation with the excitation light 402 (ΔR / R) is the change in reflection intensity. The ratio is detected by the reflection intensity observation system 220 shown in FIG. With the above configuration, the change in the change rate of the reflection intensity is monitored.

Next, in the step shown in FIG. 30C, the patterning of the gate oxide film 807 is completed, and the gate electrode 8
The gate oxide film 807a is left directly below the gate oxide film 06a. Here, in the present embodiment, when the etching is completed in this manner, the change rate (ΔR / R) of the reflectance of the probe light in the second semiconductor region 801 is as shown in FIG.
Attention is paid to the fact that the value changes more than the value shown in FIG.

FIG. 31 is a spectrum diagram showing a change ratio (ΔR / R) of the reflectance of the probe light when the gate oxide film is removed. When a gate oxide film is present as shown in FIG. 30B, a spectrum line having a large absolute value of the peak value is obtained due to the presence of trapped electrons in the gate oxide film. A spectral line having a small absolute value (for example, FIG. 31)
(Slow) shown in FIG. As the removal of the gate oxide film further proceeds, the number of trapped electrons becomes extremely small, and since the silicon substrate has almost no damage layer, the absolute value of the peak value starts to increase. Then, when the removal of the gate oxide film shown in FIG. 30C is completed, a spectrum line Shigh having a large peak value is shown. Therefore, by continuing to monitor the rate of change (ΔR / R) of the reflectance of the probe light, it is possible to detect the point at which the substrate is hardly damaged and the gate oxide film is completely removed. That is, the dry etching process can be controlled so that the etching is stopped at the time when the removal of the gate oxide film is completed, and the damage to the silicon substrate can be minimized.

However, the method of controlling the etching step according to the present embodiment is not limited to the removal of the gate oxide film, but is not limited to the removal of other insulation films unless the insulation film is thick enough to not effectively obtain measurement sensitivity. Can also be applied to the etching.

(Tenth Embodiment) Next, a tenth embodiment will be described. Although the illustration of the wafer is omitted in the present embodiment, for example, FIG.
In the state shown in (c), the method can be applied to the step of introducing impurities for forming source / drain regions in the first semiconductor region 800.

FIG. 32 shows the change rate of the probe light reflectance (ΔR / R) in the process of introducing impurities into the semiconductor region by performing plasma doping at a pressure of 10 mTorr using a mixed gas of BF 2 and He. It is a figure which shows the result of having monitored. In the figure, the horizontal axis represents the processing time, and the vertical axis represents the absolute value of the signal intensity (relative value) of the minimum peak value. As shown in the figure, the signal intensity decreases with the introduction of the impurity, and it can be seen that a defect occurs in the semiconductor region due to the introduction of the impurity. Therefore, when the change ratio (ΔR / R) of the reflectance of the probe light becomes smaller than the initial value by a predetermined value or a predetermined ratio, the introduction of the impurity is stopped or an experiment is performed in advance to meet the desired impurity concentration. By obtaining the signal intensity and performing control such as stopping the introduction of the impurity when the signal intensity is reached, it is possible to introduce the impurity of a desired concentration.

Further, a heat treatment is performed after the impurity is introduced by the above-described plasma doping or ion implantation, and a light modulation reflectance measurement is performed after the heat treatment to evaluate the change ratio (ΔR / R) of the reflectance of the measurement light. The later concentration of the impurity is known. Therefore, preliminary experiments can be performed in advance to determine impurity introduction conditions (for example, ion implantation amount, ion implantation energy, high-frequency power during plasma doping, etc.) for achieving an appropriate impurity concentration. In particular, if the in-line light modulation reflectance measurement is performed on the semiconductor region before the impurity introduction and the impurity concentration of the semiconductor region in the process is grasped, more accurate impurity introduction can be performed.

However, also in the present embodiment, a monitor area for optical evaluation can be provided in an area different from the area where the semiconductor element is formed.

(Other Embodiments) The Xe lamp, the Xe lamp,
As a polarizer, a detector, and the like, a member of an ellipsometry spectrometer currently used for measuring the thickness of an oxide film can be used as it is. In that case, an Ar ion laser,
The optical evaluation of the present invention can be performed simply by newly providing a chopper and a control system.

In each of the above embodiments, the case where a MOS transistor is formed has been described as an example. However, a bipolar transistor or a MOS transistor formed on a compound semiconductor substrate may be used.
The present invention can be applied to the case of forming a device such as an ESFET.

[0367]

According to the first to thirteenth aspects of the present invention, as an optical evaluation apparatus used for processing a substrate having a semiconductor region in a chamber, the optical evaluation device measures the light emitted from the semiconductor region by measuring the light modulation reflectance. Since the configuration is such that the change rate of the reflectance is calculated, the information obtained by the change rate of the reflectance reflecting the crystal state of the semiconductor region and the like is used to control the conditions of the processing performed in the chamber. Inline evaluation can be performed.

According to the fourteenth to twenty-fifth aspects, as an optical evaluation device for evaluating the electrical characteristics of the insulating film on the semiconductor region, a change in the reflectance of the measurement light from the semiconductor region by light modulation reflectance measurement is measured. Since the ratio is calculated and the electrical characteristics of the insulating film are evaluated based on the magnitude of the change rate of the reflectance, information on electrical defects in the insulating film such as the gate oxide film can be obtained. It is possible to quickly and surely manage the electrical characteristics of the insulating film.

According to the twenty-sixth to thirty-seventh aspects, in a semiconductor device manufacturing apparatus for processing a semiconductor region in a chamber, the function of the above-described optical evaluation device is additionally provided, and the change rate of the reflectance is changed. The processing conditions are controlled on the basis of the conditions described above, so that the conditions of the processing performed in the chamber can be controlled based on the in-line evaluation, thereby forming a semiconductor device having desired characteristics with good reproducibility. can do.

According to Claims 38 to 48, as an optical evaluation method for evaluating the state of the processing when the processing is performed in the chamber, the method of measuring the reflection of the measurement light from the semiconductor region by measuring the light modulation reflectance. The in-line optical evaluation method for controlling the processing conditions by using the rate of change of the reflectance of the measurement light, which reflects the crystal state of the semiconductor region, etc. Can be provided.

According to Claims 49 to 68, as a method of manufacturing a semiconductor device, the optical characteristics of a semiconductor region are evaluated, and the etching conditions are controlled based on the evaluated optical characteristics of the semiconductor region. By utilizing the fact that light enters the semiconductor substrate at a shallow depth, it is possible to detect the depth and the degree of damage of the damage layer generated in the semiconductor region by etching, and thus to accurately determine the characteristics of the semiconductor device. It can be controlled to a desired value with a small variation.

According to Claims 69 to 82, as a method of manufacturing a semiconductor device, the optical characteristics of a semiconductor region having a disordered structure are evaluated, and conditions are controlled based on the evaluated optical characteristics of the semiconductor region. While performing heat treatment to recover the disorder of the structure of the semiconductor region, information on the disorder of the structure near the surface of the semiconductor region can be obtained by utilizing the shallow depth of light entering the semiconductor substrate. Thus, normal characteristics of the semiconductor region can be restored under appropriate processing conditions.

According to Claims 83 to 95, as a method of manufacturing a semiconductor device, an optical characteristic of a semiconductor region is evaluated, and a condition is controlled based on the evaluated optical characteristic of the semiconductor region. Since the impurities are introduced, it is possible to realize an appropriate impurity concentration for obtaining desired characteristics by utilizing the fact that the depth at which light enters the semiconductor substrate is shallow.

According to Claims 96 to 111, as a method of manufacturing a semiconductor device, the optical characteristics of a semiconductor region are evaluated.
Since the formation conditions of the insulating film on the semiconductor region are controlled based on the evaluated optical characteristics of the semiconductor region, the insulating film is formed by utilizing the fact that light enters the semiconductor substrate at a shallow depth. The insulating film can be formed under appropriate conditions while accurately grasping the quality of the characteristics of the insulating film in the formation process.

According to Claims 112 to 127, as a method of manufacturing a semiconductor device, the optical characteristics of a semiconductor region having an insulating film formed on a surface are evaluated, and the semiconductor device is evaluated based on the evaluated optical characteristics of the semiconductor region. Since the etching condition of the insulating film is controlled by utilizing the small depth at which light enters the semiconductor substrate, the etching condition can be determined so as not to damage the semiconductor region significantly.

According to Claims 128 to 140, as a method for managing a semiconductor device manufacturing apparatus for performing the above-described light modulation reflectance measurement in a chamber, a method of processing light on a measurement light while performing processing on the substrate in the chamber. A predetermined time until the reflectance change rate reaches a predetermined value is monitored, and when the predetermined time exceeds the limit value, maintenance of the apparatus is performed, so that deterioration of components in the chamber is detected and appropriate Maintenance can be performed at the timing,
It is possible to avoid occurrence of a defect in the semiconductor region due to an excessively long processing time. According to Claims 141 to 145, as the structure of the semiconductor device, a first semiconductor region which is a part of a semiconductor element, and a second semiconductor region for optically monitoring processing in the first semiconductor region. Are provided on the same semiconductor wafer, a semiconductor device having a configuration capable of appropriately determining processing conditions such as strength and time of processing in the first semiconductor region using optical characteristics in the second semiconductor region. Can be provided.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a method for manufacturing a semiconductor device according to an embodiment.

FIG. 2 is a cross-sectional view of a wafer illustrating a manufacturing process of the semiconductor device according to the embodiment.

FIG. 3 is a top view of the wafer according to the embodiment.

FIG. 4 is a cross-sectional view of a plasma processing apparatus which is a semiconductor device manufacturing apparatus according to the embodiment.

FIG. 5 is a characteristic diagram showing a relationship between an etching time and a change ratio of a reflection intensity of probe light in the embodiment.

FIG. 6 is a characteristic diagram showing a relationship between an etching time and a contact resistance in the embodiment.

FIG. 7 is a diagram showing a difference in a variation in contact resistance value of a semiconductor device formed by using the light etching method of the embodiment and a conventional light etching method.

FIG. 8 is a perspective view schematically showing an optical monitoring system for a semiconductor device according to a second embodiment.

FIG. 9 is a cross-sectional view of a wafer showing a manufacturing step of the semiconductor device according to the second embodiment.

FIG. 10 is data showing a difference between the intensity of excitation light and the reflectance change characteristic of probe light between a sample subjected to plasma processing and a sample not subjected to plasma processing according to the second embodiment.

FIG. 11 is a perspective view schematically showing an optical monitoring system of a semiconductor device according to a third embodiment.

FIG. 12 is a perspective view schematically showing an optical monitoring system of a semiconductor device according to a fourth embodiment.

FIG. 13 is a diagram in which the change ratio of the reflection intensity of the probe light when light etching is performed for 20 seconds using the optical monitoring system of the fourth embodiment is plotted by changing the RF power.

FIG. 14 is a perspective view schematically showing an optical monitoring system of a semiconductor device according to a fifth embodiment.

FIG. 15 is a diagram in which the change ratio of the reflection intensity of the probe light when light etching is performed for 20 seconds using the optical monitoring system of the fifth embodiment is plotted by changing the RF power.

FIG. 16 is a characteristic diagram showing a relationship between an etching time and a change ratio of a reflection intensity of probe light in the fifth embodiment.

FIG. 17 is a cross-sectional view schematically showing a state where the optical monitoring systems of the third to fifth embodiments are mounted on a plasma processing apparatus.

FIG. 18 is a sectional view schematically showing a configuration of a semiconductor heat treatment apparatus according to a sixth embodiment.

FIG. 19 is a spectral diagram showing a change in the spectral shape of a change ratio of the reflectance with the annealing time in the sixth embodiment.

FIG. 20 is a diagram showing a change in a minimum peak value with respect to an annealing process time in a sixth embodiment.

FIG. 21 is a diagram showing a relationship between a dose at the time of ion implantation and a minimum peak value in the seventh embodiment.

FIG. 22 is a spectral diagram showing the rate of change in reflectance after arsenic ions are introduced at a dose of 1 × 10 ¹⁵ cm ⁻² and subjected to heat treatment.

FIG. 23 is a diagram showing a change in a required time until a minimum peak value during a heat treatment reaches a predetermined value in the sixth embodiment with respect to the number of processed wafers.

FIG. 24 is a block diagram partially showing a configuration of an optical evaluation device according to an eighth embodiment in a perspective view.

FIG. 25 is a cross-sectional view illustrating a structure of a device under test used for performing an optical evaluation in the eighth embodiment.

FIG. 26 is a spectrum diagram of a signal relating to a change ratio of the reflection intensity of the probe light from the semiconductor region in the eighth embodiment.

FIG. 27 is an energy band diagram of the silicon oxide film and the n-type semiconductor region when the excitation light is irradiated, and an energy band diagram of the silicon oxide film and the n-type semiconductor region when the excitation light is not irradiated.

FIG. 28 is a diagram showing the relationship between the peak intensity in the spectrum of the change ratio of the reflection intensity of the probe light and the density of trapped electrons in the oxide film.

FIG. 29 is a diagram showing the relationship between the number of processed wafers and the rate of change of the reflection intensity around 3.35 eV when optical evaluation is used to control the oxidation process of a prototype using the eighth embodiment. is there.

FIG. 30 is a cross-sectional view of a wafer showing a manufacturing step of the semiconductor device according to the ninth embodiment.

FIG. 31 is a spectral diagram showing a change in a change ratio of the reflectance of the measurement light in the ninth embodiment.

FIG. 32 is a diagram showing the relationship between the processing time of plasma doping and the peak intensity of the change rate of the reflectance of the measurement light in the tenth embodiment.

[Explanation of symbols]

 Reference Signs List 101 n-type semiconductor region 103 wafer 104 interlayer insulating film 105 photoresist mask 106 gate electrode 107 gate oxide film 108 n-type source region 109 n-type drain region 110a-c opening 200 reaction processing chamber 211 high frequency power supply 212 coupling capacitor 213 anode electrode 214 Cathode electrode 215 End point detection window 216 End point detection system 217 Mirror 218 Probe light input window 219 Reflected light observation window 220 Reflected intensity observation system 221 Signal path 222 Etching control system 223 Chopper 301 Ar ion laser (first light source) 302 Xe lamp (second light source) 401 plasma 402 excitation light 403 probe light 404 reflected probe light 502 Xe lamp (second light source) 503 Ar ion laser ( 504 Wafer stage 505 Microscope system 506 Mirror 507 Probe light 508 Reflected probe light 509 Observation and analysis system 510 Chopper 511 Excitation light 512 Reflection excitation light 513 Reflection excitation light observation system 525 Filter 530 Optical system 701 Semiconductor substrate 701a Main unit 701b n-type semiconductor region 701c silicon oxide film 702 wafer stage 703 Xe lamp (second light source) 704 polarizer 705 detector 706 probe light 707 reflected probe light 708 signal line 709 Ar ion laser (first light source) 710 Chopper 711 Excitation light 712 Signal line 713 Control / analysis system Rtp Chip area Rmn Monitor area Rdm1-3 Damage layer

 ──────────────────────────────────────────────────続 き Continuation of the front page (31) Priority claim number Japanese Patent Application No. 9-189841 (32) Priority date Hei 9 (1997) July 15, (33) Priority claim country Japan (JP)

Claims (145)

[Claims] 1. An optical evaluation device used when performing processing on a substrate having a semiconductor region in a chamber, wherein the first light source generates excitation light and the second light source generates measurement light. A first light guide member for intermittently irradiating the semiconductor region of the semiconductor substrate in the chamber with the excitation light generated by the first light source; and a measurement generated by the second light source. A second light guide member for irradiating the semiconductor region with light; a reflectance detecting unit for detecting a reflectance of the measurement light radiated to the semiconductor region; and a measurement light reflected from the semiconductor region A third light guide member for causing the semiconductor region to be irradiated with excitation light, and when the excitation light is not irradiated to the semiconductor region, And the difference in the reflectance of the measurement light Serial and change computing means for excitation light is calculated as the change rate of the reflectance of the measuring light divided by the reflectance of the measurement light when not illuminated, optical evaluation apparatus comprising a. 2. The optical evaluation device according to claim 1, wherein the second light guide member is configured to make the measurement light incident on the surface of the substrate from a direction substantially perpendicular to the surface. Optical evaluation device. 3. The optical evaluation device according to claim 2, wherein the first light guide member is configured to make the excitation light incident on the surface of the substrate from a direction substantially perpendicular to the surface. Optical evaluation device. 4. The optical evaluation device according to claim 3, further comprising an optical axis adjusting means configured to guide the excitation light and the measurement light on the same optical axis and send the same to the semiconductor region. The second light guide member irradiates the measurement light and the excitation light guided on the same optical axis by the optical axis adjusting means from a direction substantially perpendicular to the surface of the substrate, and from the semiconductor region. An optical evaluation device comprising a mirror that transmits reflected measurement light and excitation light upward. 5. The optical evaluation device according to claim 1, wherein the reflectance is detected after receiving the measurement light reflected from the semiconductor region and dispersing the measurement light. An optical evaluation device, further comprising a spectroscopy unit for sending the light to a light source. 6. The optical evaluation device according to claim 1, wherein the first light source and the second light source determine a wavelength of the excitation light and a wavelength of the measurement light. A beam splitter that separates the broad-spectrum light generated by the common light source into excitation light and measurement light, and is reflected from the semiconductor region. And a spectroscopic unit that receives the measurement light, splits the measurement light, and sends the split light to the reflectance detection unit. The first and second light guide members are arranged at positions that receive light from the splitter. An optical evaluation device, comprising: 7. The optical evaluation apparatus according to claim 1, wherein the change calculating means reflects the measurement light at a specific energy value of the measurement light that gives an extreme value in a spectrum of a change ratio of the reflectance of the measurement light. An optical evaluation device which calculates only the rate of change of the rate. 8. The optical evaluation device according to claim 1, wherein the measurement light reflected from the semiconductor region is received, and only a specific wavelength range is transmitted therethrough. An optical evaluation device, further comprising a filter for sending to a reflectance detecting means. 9. The optical evaluation device according to claim 7, wherein the specific energy value of the measurement light is 3.2 to 3.6 e.
An optical evaluation device, which is any one of values included in a range of V. 10. The optical evaluation device according to claim 1, wherein the reflectance detection means detects a reflectance of light in a wavelength range of 600 nm or less. 11. The optical evaluation device according to claim 10, wherein said reflectance detection means detects a reflectance of light in a wavelength range of 300 to 600 nm. 12. The optical evaluation device according to claim 1, wherein the first light guide member irradiates the excitation light intermittently at a frequency of 1 kHz or less. An optical evaluation device, comprising: 13. The optical evaluation device according to claim 1, wherein the optical evaluation device is configured using an ellipsometry spectrometer. 14. An optical evaluation device for evaluating electrical characteristics of an insulating film formed on a semiconductor region of a substrate, comprising: a first light source for generating excitation light; and a second light source for generating measurement light. A second light source; a first light guide member for intermittently irradiating the semiconductor region immediately below the excitation light generated by the first light source through the insulating film; and the second light guide member. A second light guide member for passing the measurement light generated by the light source through the insulating film to irradiate the semiconductor region to which the excitation light is intermittently radiated, and a measurement irradiating the semiconductor region. A reflectance detector for detecting the reflectance of light, a third light guide member for causing the measurement light reflected from the semiconductor region to enter the reflectance detector, and an output of the reflectance detector. When the semiconductor region is irradiated with excitation light By dividing the difference between the reflectance of the measurement light when the excitation light is not irradiated and the reflectance of the measurement light when the excitation light is not irradiated, the change rate of the reflectance of the measurement light is calculated. An optical evaluation device, comprising: a change calculating unit; and an evaluation unit configured to evaluate an electrical characteristic of the insulating film based on a magnitude of a change ratio of the reflectance of the measurement light. 15. The optical evaluation device according to claim 14, wherein the evaluation unit is configured to reflect the reflectance of the measurement light at a specific energy value of the measurement light that gives an almost extreme value in a spectrum of a change ratio of the reflectance of the measurement light. An optical evaluation device characterized in that a non-defective product is determined only when the change rate of the value is a value corresponding to an appropriate capacitance value of the insulating film. 16. The optical evaluation device according to claim 14, wherein the specific energy value of the measurement light is 3.2 to 3.6 e.
An optical evaluation device, which is any one of values included in a range of V. 17. The optical evaluation device according to claim 14, wherein the reflectance detection unit receives the measurement light reflected from the semiconductor region, and splits the measurement light. An optical evaluation device, further comprising a spectroscopy unit for sending the light to a light source. 18. The optical evaluation apparatus according to claim 14, wherein a wavelength corresponding to a specific energy value of the measurement light is received by receiving the measurement light reflected from the semiconductor region. An optical evaluation device, further comprising a filter for transmitting only measurement light in a range and sending the measurement light to the reflectance detecting means. 19. The optical evaluation device according to claim 14, wherein said reflectance detection means detects the reflectance of the measurement light in a wavelength range of 600 nm or less. 20. The optical evaluation device according to claim 19, wherein said reflectance detection means detects a reflectance of the measurement light in a wavelength range of 300 to 600 nm. 21. The optical evaluation device according to claim 14, wherein the optical evaluation device is configured using an ellipsometry spectrometer. 22. The optical evaluation device according to claim 14, wherein the optical evaluation device is attached to a chamber used for forming an oxide film of a semiconductor device. apparatus. 23. The optical evaluation device according to claim 14, wherein the second light source is a Xe lamp. 24. The optical evaluation device according to claim 14, wherein the first light source is an Ar ion laser or a He—Ne laser.
An optical evaluation device characterized by being a laser. 25. The optical evaluation device according to claim 14, wherein the first light guide member irradiates the excitation light intermittently at a frequency of 1 kHz or less. An optical evaluation device, comprising: 26. A chamber for accommodating a substrate having a semiconductor region, processing means for performing processing on the substrate in the chamber, and intermittently provided in a semiconductor region of the substrate provided in the chamber. A first light supply unit for irradiating the semiconductor region with the measurement light; a second light supply unit for irradiating the semiconductor region with the measurement light; and detecting a reflectance of the measurement light irradiated to the semiconductor region. The reflectance detection means to receive the output of the reflectance detection means, and the excitation of the difference between the reflectance of the measurement light when the semiconductor region is irradiated with excitation light and when the excitation light is not irradiated A change calculating means for calculating a value obtained by dividing the reflectance of the measurement light when the light is not irradiated as a change rate of the reflectance of the measurement light; and the change calculating means during the processing by the processing means. Output And a processing control means for controlling the processing conditions based on the change ratio of the reflectance. 27. The apparatus for manufacturing a semiconductor device according to claim 26, wherein said processing means generates plasma in said chamber to etch said semiconductor region. 28. The semiconductor device manufacturing apparatus according to claim 26, wherein the processing means generates plasma in the chamber to remove a damaged layer generated by etching the semiconductor region. A semiconductor device manufacturing apparatus. 29. The apparatus for manufacturing a semiconductor device according to claim 26, wherein said processing means introduces impurities into said semiconductor region. 30. The apparatus for manufacturing a semiconductor device according to claim 26, wherein said processing means performs annealing after implanting impurity ions into said semiconductor region. 31. The apparatus for manufacturing a semiconductor device according to claim 26, wherein said processing means forms a thin insulating film on said semiconductor region. 32. The semiconductor device manufacturing apparatus according to claim 26, wherein a thin insulating film is formed on said semiconductor region, and said processing means removes said insulating film on said semiconductor region. For manufacturing a semiconductor device, performing dry etching for the purpose. 33. The apparatus for manufacturing a semiconductor device according to claim 26, wherein the first and second light supply means are provided between a surface of the substrate and the measurement light. An apparatus for manufacturing a semiconductor device, wherein an angle is larger than an angle between a surface of the substrate and the excitation light. 34. An apparatus for manufacturing a semiconductor device according to claim 26, wherein said second light supply means irradiates a measurement light from a direction substantially perpendicular to a surface of said substrate. An apparatus for manufacturing a semiconductor device, comprising: 35. The semiconductor device manufacturing apparatus according to claim 34, wherein said first light supply means irradiates excitation light from a direction substantially perpendicular to a surface of said substrate. apparatus. 36. The semiconductor device manufacturing apparatus according to claim 27, wherein said first light supply means intermittently irradiates said excitation light at a frequency of 1 kHz or less. An apparatus for manufacturing a semiconductor device, comprising: 37. The apparatus for manufacturing a semiconductor device according to claim 26, wherein the second light supply unit and the reflectance detection unit are configured using an ellipsometry spectroscope. An apparatus for manufacturing a semiconductor device, comprising: 38. An optical evaluation method for evaluating a state of processing when a processing is performed on a substrate having a semiconductor region in a chamber, the measurement light being applied to the semiconductor region of the substrate in the chamber. Irradiating the semiconductor region with the excitation light intermittently; and a difference in reflectance of the measurement light between when the semiconductor region is irradiated with the excitation light and when the excitation light is not irradiated. And calculating a value obtained by dividing the value by the reflectance of the measurement light when the excitation light is not irradiated as a change rate of the reflectance. 39. The optical evaluation method according to claim 38, wherein, in the step of irradiating the measurement light, the measurement light is applied to a surface of the substrate from a direction substantially perpendicular to the surface. . 40. The optical evaluation method according to claim 39, wherein the step of irradiating the excitation light includes irradiating the excitation light from a direction substantially perpendicular to the surface of the substrate. . 41. The optical evaluation method according to claim 38, wherein the processing is plasma etching of the semiconductor region. 42. The optical evaluation method according to claim 38, wherein the processing is light dry etching for removing a damaged layer caused by plasma etching of the semiconductor region. An optical evaluation method characterized in that: 43. The optical evaluation method according to claim 38, wherein the processing is a process of introducing an impurity into the semiconductor region. . 44. The optical evaluation method according to claim 38, wherein the processing is annealing after implanting impurity ions into the semiconductor region. Evaluation method. 45. The optical evaluation method according to claim 38, wherein the processing is a formation of an insulating film on the semiconductor region. Method. 46. The optical evaluation method according to claim 38, wherein the processing is dry etching for removing an insulating film on the semiconductor region. Optical evaluation method. 47. The optical evaluation method according to claim 38, wherein the semiconductor region is made of n-type silicon. 48. The optical evaluation method according to claim 38, wherein, in the step of irradiating the excitation light, the excitation light is irradiated with 1 k of the excitation light.
An optical evaluation method characterized by intermittently irradiating at a frequency of less than or equal to Hz. 49. A first step of forming a substrate having a semiconductor region, a second step of evaluating optical characteristics of the semiconductor region, a third step of etching the semiconductor region, A fourth step of controlling conditions of the etching process based on the optical characteristics of the semiconductor region evaluated in the two steps. 50. The method of manufacturing a semiconductor device according to claim 49, wherein the second step includes: irradiating the semiconductor region with measurement light; and irradiating the semiconductor region with excitation light intermittently. The difference between the reflectance of the measurement light when the semiconductor region is irradiated with the excitation light and the reflectance when the excitation light is not irradiated is divided by the reflectance of the measurement light when the excitation light is not irradiated. Calculating the value as a change ratio of the reflectance of the measurement light. 51. The method of manufacturing a semiconductor device according to claim 50, wherein the step of calculating the change ratio of the reflectance is performed by the step of:
A method of manufacturing a semiconductor device, comprising: calculating a rate of change in reflectance of measurement light in a wavelength range of not more than nm. 52. The method of manufacturing a semiconductor device according to claim 51, wherein the step of calculating the change ratio of the reflectance is performed by using
A method for manufacturing a semiconductor device, comprising: calculating a change ratio of a reflectance of a measurement light in a wavelength range of up to 600 nm. 53. The method of manufacturing a semiconductor device according to claim 50, wherein in the step of calculating the change rate of the reflectance, the specific energy of the measurement light giving an extreme value of the spectrum of the change rate of the reflectance of the measurement light. A method of manufacturing a semiconductor device, comprising: calculating a rate of change in reflectance of measurement light in a value. 54. The method of manufacturing a semiconductor device according to claim 53, wherein the specific energy value of the measurement light is 3.2 to 3.6 eV.
A method of manufacturing a semiconductor device, wherein the value is any of the values included in the range. 55. The method of manufacturing a semiconductor device according to claim 50, wherein, in the step of irradiating the excitation light, the excitation light is irradiated with 1 k
A method of manufacturing a semiconductor device, wherein the semiconductor device is irradiated intermittently at a frequency of less than or equal to Hz. 56. The method of manufacturing a semiconductor device according to claim 49, wherein in the third step, dry etching using plasma is performed. Method. 57. The method for manufacturing a semiconductor device according to claim 56, wherein before the second step, a step of depositing an interlayer insulating film on the semiconductor region of the substrate; Forming an opening reaching the semiconductor region by selectively removing the opening by plasma etching. In the second step, the optical characteristics of the semiconductor region exposed at the bottom surface of the opening are evaluated. In the third step, the semiconductor region exposed on the bottom surface of the opening is subjected to light dry etching for removing a damaged layer caused by the plasma etching. In the fourth step, the semiconductor region is exposed. A method for manufacturing a semiconductor device, comprising: controlling etching conditions based on an evaluation result of optical characteristics in (1). 58. The method of manufacturing a semiconductor device according to claim 57, wherein a region of the semiconductor region where an element is formed is a source / drain region of an FET, and the opening is a contact reaching the source / drain. A method of manufacturing a semiconductor device, wherein the method is a hole. 59. The method of manufacturing a semiconductor device according to claim 58, wherein the relationship between the optical characteristics of the semiconductor region and the depth of the damaged layer is determined in advance by an experiment, and in the fourth step, the second A method for manufacturing a semiconductor device, comprising: determining a depth of a damaged layer from optical characteristics of a semiconductor region evaluated in a step; and performing light dry etching to remove the semiconductor region corresponding to the depth. 60. The method of manufacturing a semiconductor device according to claim 57, wherein in the fourth step, optical characteristics of the semiconductor region, which change according to progress of light dry etching, are reevaluated. A method of manufacturing a semiconductor device, comprising: comparing a result with an evaluation result in the second step to control etching conditions. 61. The method of manufacturing a semiconductor device according to claim 60, wherein a region of the semiconductor region where an element is formed is a source / drain region of an FET, and the opening reaches the source / drain region. A method for manufacturing a semiconductor device, comprising a contact hole. 62. The method of manufacturing a semiconductor device according to claim 50, wherein a high-concentration impurity is introduced into the semiconductor region of the substrate before the second step. Depositing an interlayer insulating film on the semiconductor region; and selectively removing the interlayer insulating film by plasma etching to form an opening reaching the semiconductor region, wherein the third step Then, light dry etching is performed on the semiconductor region exposed at the bottom surface of the opening to remove a damaged layer caused by the plasma etching, and reflection of the measurement light when the electrical characteristics of the semiconductor region becomes appropriate. An appropriate range of the rate of change of the reflectance is obtained in advance, and in the fourth step, the line is set so that the rate of change of the reflectance falls within the appropriate range. A method for manufacturing a semiconductor device, comprising performing dry etching. 63. The method of manufacturing a semiconductor device according to claim 49, wherein in the first step, the first semiconductor region serving as a part of a semiconductor element is used as the semiconductor region. And a second semiconductor region for performing an optical evaluation. In the second step, an optical characteristic of the second semiconductor region is evaluated. In the third step, the first and the second semiconductor regions are evaluated. The second semiconductor region is etched at the same time, and in the fourth step, the condition of the etching process is controlled based on an evaluation result of the optical characteristics in the second semiconductor region. Production method. 64. The method of manufacturing a semiconductor device according to claim 63, wherein in the first step, an impurity concentration in the second semiconductor region is higher than an impurity concentration in the first semiconductor region. A method for manufacturing a semiconductor device, comprising: 65. The method of manufacturing a semiconductor device according to claim 63, wherein a high concentration impurity is introduced into the second semiconductor region of the substrate before the second step. And a step of depositing a gate insulating film and a gate electrode conductive film on the second semiconductor region. In the third step, the gate electrode conductive film and the gate insulating film are patterned by plasma etching. An appropriate range of the change rate of the reflectance of the measurement light when the electrical characteristics of the region is appropriate is obtained in advance, and in the fourth step, the change rate of the reflectance is set to fall within the appropriate range. A method for manufacturing a semiconductor device, comprising performing the light dry etching. 66. The method for manufacturing a semiconductor device according to claim 65, wherein a silicon oxide film is formed as the gate insulating film. 67. The method of manufacturing a semiconductor device according to claim 49, wherein, in the first step, a portion of the semiconductor region for performing an optical evaluation is made of n-type silicon. A method for manufacturing a semiconductor device, comprising: 68. The method of manufacturing a semiconductor device according to any one of claims 50 to 55, wherein in the second step, the change ratio of the reflectance of the measurement light is measured using an ellipsometry spectrometer. A method for manufacturing a semiconductor device, characterized by evaluating. 69. A method of manufacturing a semiconductor device having a semiconductor region in which a structural disorder has occurred, comprising the steps of: evaluating optical characteristics of the semiconductor region; and optical characteristics of the semiconductor region evaluated in the step. Performing a heat treatment for restoring the disorder of the structure of the semiconductor region while controlling the conditions based on the conditions. 70. The method of manufacturing a semiconductor device according to claim 69, wherein the step of evaluating the optical characteristics includes the step of irradiating the semiconductor region with measurement light and the step of irradiating the semiconductor region with excitation light intermittently. Step, the difference between the reflectance of the measurement light when the semiconductor region is irradiated with excitation light and the time when the excitation light is not irradiated with the reflectance of the measurement light when the excitation light is not irradiated. Calculating the divided value as a change ratio of the reflectance of the measurement light. 71. The method of manufacturing a semiconductor device according to claim 70, wherein the step of calculating the change rate of the reflectance is performed by
A method of manufacturing a semiconductor device, comprising: calculating a rate of change in reflectance of measurement light in a wavelength range of not more than nm. 72. The method of manufacturing a semiconductor device according to claim 71, wherein the step of calculating the rate of change of the reflectivity includes the step of:
A method for manufacturing a semiconductor device, comprising: calculating a change ratio of a reflectance of a measurement light in a wavelength range of up to 600 nm. 73. The method of manufacturing a semiconductor device according to claim 70, wherein the step of calculating the rate of change of the reflectance includes the step of calculating the specific energy of the measurement light that gives an extreme value of the spectrum of the rate of change of the reflectance of the measurement light. A method of manufacturing a semiconductor device, comprising: calculating a rate of change in reflectance of measurement light in a value. 74. The method of manufacturing a semiconductor device according to claim 71, wherein the specific energy value of the measurement light is 3.2 to 3.6 eV.
A method of manufacturing a semiconductor device, wherein the value is any of the values included in the range. 75. The method for manufacturing a semiconductor device according to claim 70, wherein, in the step of irradiating the excitation light, the excitation light is irradiated with 1 k of the excitation light.
A method of manufacturing a semiconductor device, wherein the semiconductor device is irradiated intermittently at a frequency of less than or equal to Hz. 76. The method for manufacturing a semiconductor device according to claim 70, wherein the change rate of the reflectance of the measurement light when the electrical characteristics of the semiconductor region are appropriate is appropriate. Wherein the heat treatment is performed so that the rate of change of the reflectance of the measurement light falls within the appropriate range. 77. The method for manufacturing a semiconductor device according to claim 70, wherein a relationship between a change rate of a reflectance of the measurement light in the semiconductor region and an impurity concentration in the semiconductor region is determined. In the step of performing the heat treatment, the heat treatment of the semiconductor device is performed until the change rate of the reflectance of the measurement light in the semiconductor region reaches a change rate corresponding to a desired impurity concentration. Device manufacturing method. 78. The method of manufacturing a semiconductor device according to claim 69, wherein the semiconductor region is optically evaluated in advance with a first semiconductor region that is a part of a semiconductor element. Forming a second semiconductor region for the second semiconductor region, evaluating the optical characteristics of the second semiconductor region, evaluating the optical characteristics of the second semiconductor region, and performing the heat treatment in the first and second semiconductor regions. A method of manufacturing a semiconductor device, comprising: controlling a condition of the heat treatment based on an evaluation result of optical characteristics in the second semiconductor region while simultaneously heat treating the second semiconductor region. 79. The method of manufacturing a semiconductor device according to claim 78, wherein, in said first step, an impurity concentration in said second semiconductor region is made higher than an impurity concentration in said first semiconductor region. A method for manufacturing a semiconductor device, comprising: 80. The method of manufacturing a semiconductor device according to claim 69, wherein a portion for performing an optical evaluation in the semiconductor region is n.
A method for manufacturing a semiconductor device, comprising: a silicon substrate. 81. The method of manufacturing a semiconductor device according to claim 69, wherein a region of the semiconductor region where a semiconductor element is formed is a source / drain region. A method for manufacturing a semiconductor device. 82. The method of manufacturing a semiconductor device according to claim 70, wherein, in the second step, a change ratio of the reflectance of the measurement light is measured by using an ellipsometry spectroscope. A method for manufacturing a semiconductor device, characterized by evaluating. 83. A method of manufacturing a semiconductor device having a semiconductor region, comprising: a step of evaluating optical characteristics of the semiconductor region; and controlling a condition based on the optical characteristics of the semiconductor region evaluated in the step. And introducing an impurity into the semiconductor region. 84. The method of manufacturing a semiconductor device according to claim 83, wherein the step of evaluating the optical characteristics includes: irradiating the semiconductor region with measurement light; and irradiating the semiconductor region with excitation light intermittently. Step, the difference between the reflectance of the measurement light when the semiconductor region is irradiated with excitation light and the time when the excitation light is not irradiated with the reflectance of the measurement light when the excitation light is not irradiated. Calculating the divided value as a change ratio of the reflectance of the measurement light. 85. The method of manufacturing a semiconductor device according to claim 84, wherein the step of calculating the rate of change of the reflectivity includes the step of:
A method of manufacturing a semiconductor device, comprising: calculating a rate of change in reflectance of measurement light in a wavelength range of not more than nm. 86. The method of manufacturing a semiconductor device according to claim 85, wherein the step of calculating the change ratio of the reflectivity includes the step of:
A method for manufacturing a semiconductor device, comprising: calculating a change ratio of a reflectance of a measurement light in a wavelength range of up to 600 nm. 87. The method of manufacturing a semiconductor device according to claim 84, wherein in the step of calculating the change rate of the reflectance, the specific energy of the measurement light that gives an almost extreme value of the spectrum of the change rate of the reflectance of the measurement light. A method of manufacturing a semiconductor device, comprising: calculating a rate of change in reflectance of measurement light in a value. 88. The method for manufacturing a semiconductor device according to claim 87, wherein the specific energy value of the measurement light is 3.2 to 3.6 eV.
A method of manufacturing a semiconductor device, wherein the value is any of the values included in the range. 89. The method of manufacturing a semiconductor device according to claim 84, wherein, in the step of irradiating the excitation light, the excitation light is irradiated with 1 k
A method of manufacturing a semiconductor device, wherein the semiconductor device is irradiated intermittently at a frequency of less than or equal to Hz. 90. The method of manufacturing a semiconductor device according to claim 84, wherein the relationship between the amount of impurity introduced and the rate of change of the reflectance of the measurement light is determined in advance by an experiment. In the step of introducing an impurity in the semiconductor region, the impurity is introduced such that a change ratio of the reflectance of the measurement light becomes a value corresponding to a desired amount of the introduced impurity. Manufacturing method. 91. The method for manufacturing a semiconductor device according to claim 83, wherein the semiconductor region is optically evaluated in advance with a first semiconductor region that is a part of a semiconductor element. Forming a second semiconductor region, and evaluating the optical characteristics in the step of evaluating the optical characteristics of the second semiconductor region, and introducing the impurities in the step of introducing the impurity. A method of manufacturing a semiconductor device, comprising: simultaneously introducing an impurity into a second semiconductor region; and controlling conditions for introducing the impurity based on an evaluation result of optical characteristics in the second semiconductor region. 92. The method of manufacturing a semiconductor device according to claim 83, wherein in the third step, the impurity is introduced by plasma doping. Production method. 93. The method of manufacturing a semiconductor device according to claim 83, wherein the impurity is an n-type impurity. 94. The method of manufacturing a semiconductor device according to claim 83, wherein a region of the semiconductor region where a semiconductor element is formed is a source / drain region. A method for manufacturing a semiconductor device. 95. The method of manufacturing a semiconductor device according to any one of claims 84 to 90, wherein in the second step, the change ratio of the reflectance of the measurement light is measured using an ellipsometry spectrometer. A method for manufacturing a semiconductor device, characterized by evaluating. 96. A first step of forming a substrate having a semiconductor region; a second step of evaluating optical characteristics of the semiconductor region; and a third step of forming a thin insulating film on the semiconductor region. And a fourth step of controlling conditions for forming the insulating film based on the optical characteristics of the semiconductor region evaluated in the second step.
And a method for manufacturing a semiconductor device. 97. The method of manufacturing a semiconductor device according to claim 96, wherein the second step includes: irradiating the semiconductor region with measurement light; and irradiating the semiconductor region with excitation light intermittently. The difference between the reflectance of the measurement light when the semiconductor region is irradiated with the excitation light and the reflectance when the excitation light is not irradiated is divided by the reflectance of the measurement light when the excitation light is not irradiated. Calculating the value as a change ratio of the reflectance of the measurement light. 98. The method of manufacturing a semiconductor device according to claim 97, wherein the step of calculating the change ratio of the reflectance is performed by using
A method of manufacturing a semiconductor device, comprising: calculating a rate of change in reflectance of measurement light in a wavelength range of not more than nm. 99. The method of manufacturing a semiconductor device according to claim 98, wherein the step of calculating the rate of change of the reflectance comprises the step of:
A method for manufacturing a semiconductor device, comprising: calculating a change ratio of a reflectance of measurement light in a wavelength range of nm to 600 nm. 100. The method of manufacturing a semiconductor device according to claim 97, wherein the step of calculating the rate of change of the reflectance includes the step of calculating the specific energy of the measurement light that gives an almost extreme value of the spectrum of the rate of change of the reflectance of the measurement light. A method of manufacturing a semiconductor device, comprising: calculating a rate of change in reflectance of measurement light in a value. 101. The method of manufacturing a semiconductor device according to claim 100, wherein the specific energy value of the measurement light is 3.2 to 3.6 eV.
A method of manufacturing a semiconductor device, wherein the value is any of the values included in the range. 102. The method of manufacturing a semiconductor device according to any one of claims 97 to 101, wherein the step of irradiating the excitation light is performed by applying 1 k
A method of manufacturing a semiconductor device, wherein the semiconductor device is irradiated intermittently at a frequency of less than or equal to Hz. 103. The method of manufacturing a semiconductor device according to claim 97, wherein the rate of change of the reflectance of the measurement light corresponding to an appropriate range of the electrical characteristics of the insulating film is determined in advance by an experiment. An appropriate range is obtained in advance, and in the fourth step, the insulating film is formed such that the change rate of the reflectance of the measurement light evaluated in the second step falls within the appropriate range. A method for manufacturing a semiconductor device. 104. The method of manufacturing a semiconductor device according to claim 97, wherein in the second step, the reflectance of the measurement light in the semiconductor region before the insulating film is formed. In the fourth step, the rate of change of the reflectance of the measurement light in the semiconductor region, which changes in accordance with the progress of the formation of the insulating film, is re-evaluated. A method for manufacturing a semiconductor device, comprising: controlling a condition for forming an insulating film by comparing an evaluation result in a second step. 105. The method for manufacturing a semiconductor device according to claim 96, wherein in the first step, the first semiconductor region serving as a part of a semiconductor element is used as the semiconductor region. And a second semiconductor region for performing an optical evaluation. In the second step, an optical characteristic of the second semiconductor region is evaluated. In the third step, the first and the second semiconductor regions are evaluated. Forming an insulating film on the second semiconductor region at the same time; and in the fourth step, controlling the formation conditions of the insulating film based on the result of evaluating the optical characteristics in the second semiconductor region. A method for manufacturing a semiconductor device. 106. The method of manufacturing a semiconductor device according to claim 105, wherein, in the first step, an impurity concentration in the second semiconductor region is higher than an impurity concentration in the first semiconductor region. A method for manufacturing a semiconductor device, comprising: 107. The method of manufacturing a semiconductor device according to claim 96, wherein, in said first step, a portion of said semiconductor region for performing an optical evaluation is made of n-type silicon. A method for manufacturing a semiconductor device, comprising: 108. The method of manufacturing a semiconductor device according to claim 97, wherein after the fourth step, the change ratio of the reflectance of the measurement light obtained in advance by an experiment and the insulation A method for manufacturing a semiconductor device, further comprising the step of determining the quality of a formed insulating film based on a relationship with electrical characteristics of the film. 109. The method of manufacturing a semiconductor device according to claim 96, wherein in the third step, a silicon oxide film is formed as the insulating film. Manufacturing method. 110. The method of manufacturing a semiconductor device according to claim 96, wherein in the third step, a gate insulating film is formed as the insulating film. Manufacturing method. 111. The method of manufacturing a semiconductor device according to claim 97, wherein in the second step, the change rate of the reflectance of the measurement light is changed using an ellipsometry spectrometer. A method for manufacturing a semiconductor device, characterized by evaluating. 112. A first step of forming a substrate having a semiconductor region and a thin insulating film thereon, a second step of evaluating optical characteristics of the semiconductor region, and dry etching of the insulating film A third step of removing, and a fourth step of controlling a removing condition of the insulating film based on the optical characteristics of the semiconductor region evaluated in the second step.
A method for manufacturing a semiconductor device, comprising: 113. The method of manufacturing a semiconductor device according to claim 112, wherein the second step is a step of irradiating the semiconductor region with a measuring beam having passed through the insulating film, and the step of irradiating the semiconductor region with the insulating film. Intermittently irradiating the excitation light that has passed through, and the excitation light determines the difference in the reflectance of the measurement light when the semiconductor region is irradiated with the excitation light and when the excitation light is not irradiated. Calculating a value obtained by dividing the reflectance of the measurement light when it is not irradiated as a change rate of the reflectance of the measurement light. 114. The method of manufacturing a semiconductor device according to claim 113, wherein the step of calculating the change rate of the reflectance is performed by the step of:
A method of manufacturing a semiconductor device, comprising: calculating a rate of change in reflectance of measurement light in a wavelength range of not more than nm. 115. The method of manufacturing a semiconductor device according to claim 114, wherein the step of calculating the change rate of the reflectance is performed by using
A method for manufacturing a semiconductor device, comprising: calculating a change ratio of a reflectance of a measurement light in a wavelength range of up to 600 nm. 116. The method of manufacturing a semiconductor device according to claim 113, wherein, in the step of calculating the change rate of the reflectance, the measurement light which gives an extreme value of the spectrum of the change rate of the reflectance of the measurement light is specified. A method for manufacturing a semiconductor device, comprising: calculating a rate of change in reflectance of measurement light in an energy value. 117. The method for manufacturing a semiconductor device according to claim 116, wherein the specific energy value of the measurement light is 3.2 to 3.6 eV.
A method of manufacturing a semiconductor device, wherein the value is any of the values included in the range. 118. The method of manufacturing a semiconductor device according to claim 113, wherein, in the step of irradiating the excitation light, the excitation light is irradiated with 1 k of the excitation light.
A method of manufacturing a semiconductor device, wherein the semiconductor device is irradiated intermittently at a frequency of less than or equal to Hz. 119. The method of manufacturing a semiconductor device according to claim 113, wherein the change rate of the reflectance of the measurement light when the removal of the insulating film is properly completed in advance. In the fourth step, the dry etching of the insulating film is performed so that the change rate of the reflectance of the measurement light evaluated in the second step falls within the appropriate range. Device manufacturing method. 120. The method of manufacturing a semiconductor device according to claim 113, wherein, in the second step, a reflectance of the measurement light in the semiconductor region when the insulating film is formed. In the fourth step, the rate of change of the reflectance of the measurement light in the semiconductor region, which changes with the progress of the removal of the insulating film, is reevaluated. A method for manufacturing a semiconductor device, comprising: controlling a condition for removing an insulating film by comparing an evaluation result in the second step. 121. The method of manufacturing a semiconductor device according to claim 112, wherein, in the first step, a first semiconductor region which is a part of a semiconductor element as the semiconductor region And a second semiconductor region for performing an optical evaluation. In the second step, an optical characteristic of the second semiconductor region is evaluated. In the third step, the first and the second semiconductor regions are evaluated. The second semiconductor region is etched at the same time, and in the fourth step, the condition of the etching process is controlled based on an evaluation result of the optical characteristics in the second semiconductor region. Production method. 122. The method of manufacturing a semiconductor device according to claim 121, wherein in the first step, an impurity concentration in the second semiconductor region is higher than an impurity concentration in the first semiconductor region. A method for manufacturing a semiconductor device, comprising: 123. The method of manufacturing a semiconductor device according to claim 112, wherein, in the first step, a portion of the semiconductor region for performing an optical evaluation is made of n-type silicon. A method for manufacturing a semiconductor device, comprising: 124. The method of manufacturing a semiconductor device according to claim 112, wherein in the first step, a silicon oxide film is formed as the insulating film. Manufacturing method. 125. The method of manufacturing a semiconductor device according to claim 112, wherein in the first step, a gate insulating film is formed as the insulating film. Manufacturing method. 126. The method for manufacturing a semiconductor device according to claim 125, wherein in the first step, a conductive film for a gate electrode is formed on the gate insulating film, and in the third step, the gate electrode is formed. A method of manufacturing a semiconductor device, comprising: patterning a conductive film for use, and then patterning the gate insulating film. 127. The method of manufacturing a semiconductor device according to any one of claims 113 to 120, wherein in the second step, the change ratio of the reflectance of the measurement light is changed by using an ellipsometry spectroscope. A method for manufacturing a semiconductor device, characterized by evaluating. 128. A chamber for accommodating a substrate having a semiconductor region, processing means for performing processing on the substrate in the chamber, and an intermittently disposed semiconductor region of the substrate provided in the chamber. A first light supply unit for irradiating the semiconductor region with the excitation light, a second light supply unit for irradiating the semiconductor region with the measurement light, and detecting a reflectance of the measurement light irradiated on the semiconductor region. A method for managing a semiconductor device manufacturing apparatus, comprising: a first step of irradiating the semiconductor region with measurement light; and a second step of intermittently irradiating the semiconductor region with excitation light. And the difference between the reflectance of the measurement light when the semiconductor region is irradiated with the excitation light and the reflectance of the measurement light when the excitation light is not irradiated. The reflectance of the measurement light when the excitation light is not irradiated Divided by A third step of calculating the value as a change rate of the reflectance of the measuring light; and operating the processing means for a predetermined time until the change rate of the reflectance calculated in the third step reaches a predetermined value. Monitoring the predetermined time in the fourth step, and
And a fifth step of outputting a signal for performing maintenance of the semiconductor device manufacturing apparatus when the predetermined time exceeds a limit value. 129. The method according to claim 128, wherein said processing means generates plasma in said chamber to etch said semiconductor region. Manufacturing equipment management method. 130. The method for managing a semiconductor device manufacturing apparatus according to claim 128, wherein said processing means generates plasma in said chamber and removes a damaged layer generated by etching of said semiconductor region. A method for managing a semiconductor device manufacturing apparatus, comprising performing dry etching. 131. The method of managing a semiconductor device manufacturing apparatus according to claim 128, wherein said processing means introduces impurities into said semiconductor region. 132. The method of managing a semiconductor device manufacturing apparatus according to claim 128, wherein said processing means performs annealing after ion implantation into said semiconductor region. Management method. 133. The method for managing a semiconductor device manufacturing apparatus according to claim 128, wherein said processing means forms a thin insulating film on said semiconductor region. Method. 134. The method for managing a semiconductor device manufacturing apparatus according to claim 128, wherein a thin insulating film is formed on said semiconductor region, and said processing means removes said thin insulating film on said semiconductor region. A method for managing a semiconductor device manufacturing apparatus for a semiconductor device, comprising performing dry etching for removal. 135. The method for managing a semiconductor device manufacturing apparatus according to claim 128, wherein the reflectance detecting means detects a reflectance of the measurement light in a wavelength range of 600 nm or less. A method for managing an apparatus for manufacturing a semiconductor device, comprising: 136. The method for managing a semiconductor device manufacturing apparatus according to claim 135, wherein said reflectivity detecting means detects a reflectivity of measurement light in a wavelength range of 300 to 600 nm. Manufacturing equipment management method. 137. The method of managing a semiconductor device manufacturing apparatus according to any one of claims 128 to 136, wherein the step of calculating the change rate of the reflectivity includes calculating the change rate of the reflectivity of the measurement light. A method of managing a semiconductor device manufacturing apparatus, comprising: calculating a change rate of a reflectance of a measurement light at a specific energy value of the measurement light that gives an almost extreme value of a spectrum. 138. The method of managing a semiconductor device manufacturing apparatus according to any one of claims 128 to 137, wherein the reflectance detecting means uses an optical filter to reflect a specific wavelength of reflected light. A method for managing an apparatus for manufacturing a semiconductor device, characterized in that the apparatus is configured to detect the following. 139. The method for managing a semiconductor device manufacturing apparatus according to any one of claims 128 to 138, wherein the semiconductor region is made of n-type silicon. Manufacturing equipment management method. 140. The method of managing a semiconductor device manufacturing apparatus according to claim 128, wherein the step of irradiating the excitation light is performed by reducing the excitation light by 1 k.
A method for managing a semiconductor device manufacturing apparatus, comprising: intermittently irradiating a semiconductor device at a frequency of not more than Hz. 141. A substrate, a first semiconductor region provided on the substrate and being a part of a semiconductor element formed on the substrate, and optical characteristics of the first semiconductor region during processing are monitored. And a second semiconductor region for the semiconductor device. 142. The semiconductor device according to claim 141, wherein the second semiconductor region is provided in a region different from a region where a semiconductor chip including the semiconductor element is formed. . 143. The semiconductor device according to claim 142, wherein the second semiconductor region is provided in a region where a semiconductor chip including the semiconductor element is formed. 144. The semiconductor device according to claim 141, wherein the second semiconductor region is a region made of a semiconductor material for monitoring by light modulation reflectance spectroscopy. A semiconductor device characterized by the above-mentioned. 145. The semiconductor device according to any one of claims 141 to 144, wherein said second semiconductor region is made of n-type silicon.