JPH05295543A - Vacuum treatment device and film forming method and film forming device using this device - Google Patents

Abstract

PURPOSE:To provide the vacuum treatment device which can control the temp. of a base body by exactly measuring the temp. in a vacuum, the film forming device which applies this vacuum treatment device, the film forming method by this film forming device and the method for measuring the temp. of the base body. CONSTITUTION:The radiation heat of the base body 10 is measured by IR radiation thermometers 11, 14, 15 in a vacuum treatment device 1 to determine a radiation rate. The calibration of the radiation rate in combination with a shutter 20 is executed in a temp. calibration stage 5 and thereafter, the temp. is controlled to the prescribed temp. by a controller 13 in a temp. regulating stage 6 and thereafter, the substrate is transported to a sputtering stage 7 and is subjected to the film formation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum processing apparatus for performing various kinds of processing on a substrate in a vacuum, a film forming apparatus and a film forming method using the same, and particularly to a manufacturing process of a semiconductor device. The present invention relates to a suitable vacuum processing apparatus, a film forming apparatus using the same, and a film forming method.

[0002]

2. Description of the Related Art In a process apparatus used for manufacturing a semiconductor device, accurate control of a process temperature is important in order to realize well-controlled reactions. A typical process apparatus in which the temperature is the most important setting condition is a so-called furnace body such as an oxidation furnace. The inside of this type of furnace body is an oxidizing atmosphere in which the atmosphere is replaced. In this case, the substitution atmosphere is atmospheric pressure or higher, and the silicon wafer in the furnace body is heated by radiation from a heater installed around the quartz tube and heat conduction by the atmospheric pressure atmosphere in the quartz tube. .. That is, since there is a medium that conducts heat, the temperature can be measured relatively accurately by using a probe such as a thermocouple installed in the heat conducting atmosphere.

Further, as an example in which a heat-conducting medium is not used, there can be mentioned, for example, a photoresist baking apparatus used in a step of applying a photoresist used as a mask in an etching step. In this apparatus, baking is performed in an atmospheric pressure atmosphere, but the silicon wafer is placed on a heat block having a larger heat capacity than the silicon wafer heated to a predetermined baking temperature, and the silicon wafer is further provided on the heat block side. The entire surface of the silicon wafer is pressed against the heat block by the atmospheric pressure by the vacuum chuck. For this reason, the temperature of the wafer is balanced with the temperature of the heat block, so that the temperature of the wafer can be accurately controlled and managed by a temperature probe such as a thermocouple attached to the heat block. Many semiconductor manufacturing processes utilize highly pure materials and well-controlled reactions in a dust-free environment, and therefore often require processing in vacuum.

Conventionally, accurate temperature control of a wafer in a vacuum in a semiconductor manufacturing apparatus has been essentially difficult for the following reasons.

That is, in the heating by the lamp heater, since there is no medium for transmitting heat, the wafer is heated only by radiation, so that it is well known that only a small absorption occurs on the metal mirror surface and a large amount on the black body. Absorption occurs, and as a result, the degree of heating greatly varies depending on the surface state of the heated wafer.

Although attempts have been made to accurately measure the temperature of the wafer during the process by attaching the thermocouple to the wafer, the thermocouple is used to measure the temperature of the wafer with the thermocouple in point contact with the wafer. It is difficult to stabilize the contact state at a constant level, and there is the drawback that the reproducibility of the measurement temperature is poor.

When the wafer is heated by infrared radiation, since the wafer is almost transparent in a wide range of infrared region, heat is not transferred only to the thermocouple by conduction from the wafer, but the thermocouple itself. Accurate temperature measurement of the wafer is difficult because it may be heated by the lamp heater.

There is also a method of forcibly bringing a conductive medium into a vacuum. For example, as described in JP-A-56-48132 or JP-A-58-213434, a silicon wafer is clamped to a heat block installed in a vacuum atmosphere, and the back surface of the silicon wafer and the heat block are separated from each other. The temperature of the wafer is balanced with the temperature of the heat block by filling the gas with a pressure of around 1 Torr. In this case, the temperature of the heat block can be measured by a temperature probe such as a thermocouple attached to the heat block.

However, in this example, since the wafer is clamped to the heat block with a small force as compared with the use of the vacuum chuck under the atmospheric pressure, the temperature uniformity and reproducibility are not sufficient. The biggest drawback is that the heat transfer from the heat block to the wafer takes time due to the low density of the heat transfer medium. Eventually, even if the heat block and the wafer reach thermal equilibrium, it takes several seconds to several tens of seconds as described in the above example,
Further, it is considered that various factors influence the reproducibility of the heat conduction time.

Further, according to this method, since the surface of the substrate and the pressing member are in physical contact with each other, the surface of the substrate is contaminated, foreign matter is generated, etc., and product yield is reduced. There is.

As described above, whichever heating means is used, it is necessary to measure the wafer temperature in vacuum in a non-contact manner. As one of the methods, a method of measuring the radiation intensity from a wafer in the infrared region using an infrared radiation thermometer has been proposed.

That is, in the present method, the temperature of the wafer is measured by an infrared radiation thermometer through a through hole formed in a target placed facing the wafer while the wafer is placed on a heat stage and heated in a sputtering apparatus. It is a thing. That is, the infrared emissivity of the wafer at a specific temperature is measured in advance by another calibration sample, and the wafer temperature during sputtering is controlled by the measured value.

As a technique related to this type of technique, for example, Japanese Patent Laid-Open No. 1-129966 can be cited.

[0014]

However, since the emissivity of the wafer is not always constant in this method as described below, accurate temperature measurement is difficult and there are some problems.

That is, although the same metal as the target material, for example, another silicon wafer on which aluminum is deposited by several hundred liters is used as the calibration sample, the metal on the surface of the wafer on the side to be observed by the infrared radiation thermometer is actually used. With or without membrane,
Since the infrared emissivity from the wafer surface is different, the temperature control before film formation cannot be performed.

Further, even after the film formation is started, accurate temperature measurement cannot be performed until the film is formed to a certain film thickness (for example, aluminum of several hundred Å).

In order to accurately measure the temperature of the wafer in vacuum and to control the temperature accordingly, even if the same metal film is formed on the wafer, the infrared emissivity differs depending on the product lot. With the method of separately preparing a wafer for use, accurate temperature control cannot be performed because it is not the wafer on which the film is actually formed. As described above, in the conventionally used vacuum processing apparatus, although various temperature control means are used, none of them can accurately control the temperature of the process.

In addition, in semiconductor materials such as Si wafers, the infrared emissivity increases with temperature. This is because the density of free carriers increases with temperature and the radiation / absorption of (metallization) increases. For details, see T. Sato; Japanese Journal of Applied Physics, Vo.
L.6, No. 3 (1967).

Due to this variation of emissivity with temperature,
For highly accurate temperature measurement, emissivity correction at multiple temperatures is necessary. For that purpose, emissivity measurement at a plurality of temperatures in the temperature range to be measured may be performed in advance, but heating at this time increases the number of heat treatment steps that are substantially unnecessary in the process. ..

On the other hand, however, for a process that requires extremely highly accurate temperature control, it is also necessary to correct the emissivity for each wafer at a temperature as close as possible to the process temperature.

That is, the ideal method of controlling the temperature of the wafer using the infrared radiation temperature is to calibrate the infrared radiation thermometer using the wafer itself on which the film is actually formed, and to determine the infrared radiation depending on the presence or absence of the film and its state. It is a method that can be measured without being affected by the difference in emissivity. However, what has been put into practical use has not been proposed yet.

Further, in a vacuum processing apparatus having a plurality of vacuum processing chambers and a so-called multi-chamber type vacuum processing apparatus in which the vacuum processing chambers are arranged around the transfer chamber, a temperature measuring mechanism is installed in the vacuum processing chamber itself. In this case, there are the following problems (1) obstacles due to intrusion of thermal noise from a heat source in the vacuum processing chamber, (2) vacuum performance of the vacuum processing chamber, for example, increase in leak potential, ( 3) Contamination of the optical system by generation of film-forming particles and generation of dust. (4) When applied to existing equipment, a vacuum device such as a substrate holder for mounting the substrate in a vacuum processing chamber. Regarding the necessity of changing the design specifications, (5) economic problems such as the need for temperature measurement mechanisms for the number of vacuum processing chambers, and highly accurate temperature measurement. Any practical approach in the coming technology has not been taken into account.

Therefore, an object of the present invention is to eliminate the above-mentioned conventional problems, and the first object thereof is an improved vacuum processing apparatus capable of accurately measuring and controlling the temperature of a substrate in vacuum. The second purpose is to apply this vacuum processing apparatus, for example, a sputtering apparatus or a CVD (Chemical Vapor).
and a third object is to provide a film forming method using the improved film forming apparatus.

[0024]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present inventors conducted various studies as described below and obtained various findings.

That is, in the present invention, since the infrared radiation thermometer is used as a main temperature measuring means, calibration is performed for each substrate (eg, silicon wafer). Specifically, before the substrate is processed by the target vacuum processing apparatus, at least one point of low temperature, which is as close as possible to the environmental temperature for each substrate in the stage in the temperature calibration chamber,
The temperature of the substrate is measured by the first infrared radiation thermometer. From the indicated value of the first infrared radiation thermometer obtained at this time, the infrared radiation thermometer in the vacuum processing chamber after the temperature calibration chamber is corrected. Specifically, the infrared radiation thermometer after the temperature calibration chamber is calibrated by knowing this correction value in advance and, for example, a rough correction, or a simple coefficient if a narrow temperature range is targeted. In the case of having a plurality of temperature correction points, it is possible to adopt a method in which each temperature correction data is created in advance by a computer and calculation for correction is performed.

In a process requiring more accurate temperature measurement and control, a method of calibrating the infrared radiation thermometer at the process temperature can be adopted.

The temperature calibration stage described above is not limited to a vacuum, and may be in an environment of atmospheric pressure. Under atmospheric pressure environment, not only the device structure is generally simple,
When heating or cooling to a known temperature, it is possible to bring the temperature of the target wafer closer to the temperature of the heat block (stage) more easily.

Specifically, when the temperature calibration chamber is set under the atmospheric pressure, it is possible to use a vacuum chuck on the stage and bring the substrate into close contact with a heat block having a larger heat capacity than the substrate. By doing so, the temperature of the substrate can be brought closer to the heat block temperature more accurately and in a short time.

Even when the heating block is not used and the positive heating or cooling is not performed, the vacuum chuck is used to quickly move the substrate to the stage temperature (in this case, ambient temperature to 20 ° C.). Can be equilibrated.

Further, an electrostatic chuck (by the lines of electrostatic force) can be used instead of the above vacuum chuck.

When it is necessary to raise the temperature at the temperature calibration point, there is a problem that the surface of the target substrate is oxidized depending on the atmosphere. Therefore, the atmosphere in the temperature calibration chamber is replaced with the atmosphere. For example, a nitrogen or argon atmosphere is more preferable.

When the temperature calibration chamber is set under vacuum, in order to improve the heat conduction between the heat block and the substrate as described above, heating or cooling gas is heated between them with a pressure of 5 Pascal or more. By interposing it as a conductive medium, the substrate temperature approaches the heat block in a relatively short time.

The electrostatic chuck can also be used to bring the substrate into contact with the heat block.

For example, in an apparatus for forming a thin film on a substrate by a sputtering method, the moisture adsorbed on the surface of the substrate is sufficiently removed when the substrate in the air is taken into the vacuum processing tank. Therefore, it is necessary to heat the substrate to 150 ° C. or higher, and conversely, it is necessary to lower the temperature of the substrate that has already been heated to a film formation start temperature of about 50 ° C. in the vacuum chamber. There are cases such as In the case of this temperature increase / decrease, it is necessary to measure the temperature accurately each time the temperature is controlled, and it is necessary to perform temperature calibration for each substrate in advance for the infrared radiation thermometer that measures these temperatures.

That is, the substrate is controlled to a known temperature in advance before the predetermined vacuum treatment, the emissivity of the substrate is measured by the first infrared radiation thermometer, and the subsequent vacuum treatment process is performed based on the measurement result. If a film forming apparatus that has a function of calibrating a single infrared radiation thermometer or a plurality of second infrared radiation thermometers used in, and that needs to accurately control the temperature of the substrate, such as a sputtering apparatus or a CVD apparatus, is constructed, A process suitable for electronic parts can be realized.

In general, the infrared radiation characteristic of a substance depends on the wavelength, so that the above-mentioned measurement by the first and second infrared radiation thermometers can be carried out at wavelengths in the same infrared region for more accurate calibration. And

When the emissivity measurement by the first infrared radiation thermometer at the known temperature is performed on the heated substrate, if the heating operation to the known temperature is performed in vacuum, the water adsorbed on the substrate is removed. Since it can be used also as a so-called baking process for, the apparatus scale can be reduced, which is preferable in some cases.

For example, when the temperature of the substrate is raised in the vacuum processing chamber of the sputtering apparatus, if the infrared radiation thermometer is calibrated beforehand, radiant heating by a lamp can be performed instead of using a heat block, A cheaper sputtering device can be configured. When heating with a lamp in the vacuum processing chamber, the light from the lamp may enter the infrared radiation thermometer as stray light, so the measurement wavelength of the infrared radiation thermometer is in a wavelength range different from the wavelength emitted by the lamp. Is essentially preferred.

When a silicon wafer is used as the substrate, for example, since the silicon wafer is almost transparent in the infrared region, an infrared lamp containing quartz glass, which is widely used, cannot efficiently heat the substrate. Further, since an infrared lamp of this type is likely to become stray light with respect to the infrared radiation thermometer, it is more preferable to use a lamp having a short wavelength with a high absorption efficiency of a silicon wafer.

When the temperature at which film formation on the substrate is started in the vacuum processing chamber is lower than the baking heating temperature in vacuum for removing the adsorbed moisture from the substrate, after baking is performed. Then, it is necessary to cool the substrate to a predetermined temperature in the vacuum chamber and adjust the substrate to a predetermined film formation start temperature. In order to realize such a film forming process with high accuracy, a stage equipped with a first infrared radiation thermometer for performing temperature calibration in the temperature calibration chamber, and a stage for baking the substrate in vacuum A stage for cooling to a temperature at which a predetermined film formation is started before further film formation,
And a second infrared radiation thermometer capable of automatically and accurately measuring the substrate temperature at the cooling stage by using a correction value calculated based on the emissivity obtained by the first infrared radiation thermometer. Sputtering equipment is required.

Further, in the case of an apparatus for forming a metal film by sputtering, since the infrared ray radiated to the surface opposite to the surface on which the metal film formed on the substrate is observed is reflected, a shutter as described later is used. If there is no film, the size of the radiation incident on the infrared radiation thermometer differs depending on the presence or absence of the film, and the apparent infrared emissivity differs, but to the surface of the substrate opposite to the surface observed by the infrared radiation thermometer due to the shutter. Since most of the radiated infrared rays are reflected, the difference in apparent infrared emissivity before and after film formation can be significantly reduced.

Further, in the stage for heating or cooling the substrate, the substrate is close to the surface opposite to the surface observed by the infrared radiation thermometer through the opening window of the stage, and is sufficient for the measurement wavelength of the infrared radiation thermometer. By disposing the shutter mechanism whose main surface is composed of a member that is a mirror surface, it is possible to block stray light penetrating the base and entering the infrared radiation thermometer.

Further, as means for solving practical problems in the multi-chamber type film forming apparatus, a vacuum processing chamber having means for heating or cooling the substrate to a predetermined set temperature, and a vacuum film forming process for the substrate. A vacuum film forming chamber having a means for performing the above, a vacuum chamber or a transfer chamber having a transfer robot for transferring the substrate to the vacuum film forming chamber, and radiant heat of the substrate in the transfer chamber. A vacuum processing apparatus characterized by having an infrared radiation thermometer for measuring the temperature and a reflector that is provided so as to face the substrate and that reflects radiant heat with a member that is a mirror surface with respect to the measurement wavelength of the infrared radiation thermometer. And loading the substrate into the vacuum processing apparatus, moving the substrate to the transfer chamber, and then moving the substrate to the vacuum processing chamber and the vacuum processing chamber. Characterized in that the substrate is subjected to a predetermined vacuum treatment in a chamber, and then the temperature of the substrate is measured in a transfer chamber, the vacuum treatment includes a step of heating or cooling the substrate, a step of cleaning the substrate, In the step of forming a thin film on the substrate, a film forming method characterized by using a single step or a combination of a plurality of steps in the vacuum treatment can be adopted.

[0044]

In the temperature calibration chamber, the substrate is heated or cooled to a known temperature and the temperature of the substrate is measured by the first infrared radiation thermometer and the thermocouple before the substrate is subjected to the predetermined treatment in the vacuum processing chamber. The infrared radiation thermometer correction value, that is, the emissivity is calculated based on the measurement result.
Based on this calculation result, the temperature of the substrate in the vacuum processing chamber thereafter is accurately measured by the second and third thermometers. Then, based on the measurement result, the temperature control system is operated to set the temperature of the substrate in the vacuum processing chamber to a predetermined value, and the vacuum processing such as the film forming processing is performed under the condition that the temperature is accurately controlled.

In the present invention, disposing the shutter close to the substrate when measuring the temperature of the substrate plays a very important role in accurately measuring the temperature of the substrate.

The first role is very similar to the case where a metal film is formed by this shutter in the case of an apparatus for forming a metal film by sputtering or CVD, regardless of the presence or absence of the metal film. Since it is possible to obtain the infrared emissivity, it is possible to correct the apparent difference in the infrared emissivity before and after film formation, and to enable correct temperature control of the substrate based on accurate temperature measurement. The role of is to block stray light penetrating the substrate and entering the infrared radiation thermometer to prevent measurement errors due to stray light.

This shutter mechanism is indispensable especially on the thermometer side of the substrate before film formation.

Note that other actions that cannot be explained here will be specifically explained in the section of the embodiment.

[0049]

Embodiments of the present invention will be described below with reference to the drawings.

Example 1. FIG. 1 is a schematic configuration diagram showing an embodiment in which the vacuum processing apparatus of the present invention is applied to a sputtering film forming apparatus. In this embodiment, a silicon wafer is used as a film formation target, and an example in which an Al thin film is formed thereon by sputtering will be described as a typical example.

The vacuum processing apparatus 1 of the present invention comprises a wafer temperature calibration chamber 2 having a wafer temperature calibration stage 5, a wafer temperature adjustment chamber 3 having a wafer temperature adjustment stage 6 for heating and cooling the wafer, and a sputter deposition. It is composed of three chambers, a stage 7, an Al target 8 and a sputter deposition chamber 4 having a sputter electrode 9. Each of these chambers has a gate valve G
It is connected by V1 and GV2 and is independent. An exhaust system is connected to each of the chambers 2, 3 and 4, and a predetermined vacuum state can be maintained on the one hand, and a predetermined gas can be introduced from the gas introduction port on the other hand, so that the wafer temperature calibration chamber 2
Is configured so that the atmosphere can be set to the atmospheric pressure in the replacement atmosphere by introducing air or nitrogen gas, and the sputtering film forming chamber 4 is configured to introduce the sputtering gas and set the environment in which plasma is generated by a predetermined discharge. There is. Furthermore, each stage is provided with heating and cooling means as will be described later, and an opening window 19 made of a through hole for observing radiant infrared rays from the wafer 10 is provided.
Optically coupled through the opening window 19 to the first and second
And the third infrared radiation thermometers 11, 14 and 15 are connected, and the wafer 10 on each of the stages 5, 6 and 7 is connected.
The shutters 20 and 21, whose main surface is composed of a member that is sufficiently a mirror surface for the measurement wavelength of the infrared radiation thermometer,
22 are arranged close to each other.

The wafer temperature calibration stage 5 is provided with a thermocouple 12 for accurately measuring the temperature of the wafer temperature calibration stage 5. Then, the output of the thermocouple 12 and the infrared emissivity of the wafer 10 measured by the first infrared radiation thermometer 11 are input to the arithmetic processing section of the wafer temperature controller 13.
A means for estimating the infrared emissivity of the wafer in the temperature range to be measured for the wafer 10 as a function of the temperature of the wafer based on the infrared emissivity;
Observing the temperature of the wafer during vacuum processing by means of a thermometer, and by means of converting the electric output of the second thermometer into temperature based on the infrared emissivity determined as a function of the temperature for the wafer, respectively. Wafer 1 on the stage
Measure the correct temperature of 0. Further, finally, based on these measurement data, a command to set a predetermined stage temperature is fed back to the heating and cooling means of each stage to set and control the temperature of the stage to a predetermined value. A wafer temperature controller 13 for managing the wafer temperature is provided.

Explaining the function of each chamber, the wafer temperature calibration chamber 2 normally holds the wafer 10 placed on the calibration stage 5 at the same environmental temperature as that of the calibration stage. Has a function of estimating the infrared emissivity of as a function of temperature and obtaining the relationship between the thermometer output specific to the wafer 10 and the temperature.

The wafer temperature adjusting chamber 3 has a temperature adjusting function before the wafer is transferred to the next sputter film forming chamber 4, and the sputter film forming chamber 4 has a function of forming a film on the wafer by sputtering.

A specific example in which the temperature of each stage is controlled to hold the wafer 10 at a predetermined temperature and an Al thin film is sputtered on the wafer 10 from the Al target 8 will be described.

First, in the wafer temperature calibration chamber 2 placed in a vacuum atmosphere, the wafer 10 is calibrated by the calibration stage 5.
The upper surface is brought into contact with the electrostatic chuck mechanism, and Ar gas of 5 Pascal is introduced into the space between the calibration stage 5 and the wafer 10 by a gas introduction mechanism (not shown) to set the ambient temperature to 20
The backside of the wafer 10 is controlled and controlled by the first infrared radiation thermometer 11 and the thermocouple 12, and the infrared emissivity of the wafer 10 is calculated as a function of temperature by the arithmetic processing unit of the wafer temperature controller 13. The relationship between the thermometer output wafer temperature unique to the wafer 10 is calculated, and a thermometer output-temperature conversion table is created. The details of the creation of the emissivity / thermometer output-temperature conversion table will be described later.

Since the temperature of the wafer 10 on each stage can be obtained from the thermometer output-temperature conversion table obtained from the first infrared radiation thermometer 11, the wafer temperature adjustment in the subsequent vacuum is performed. The processing temperature of the wafer 10 on the chamber 3 and the sputter deposition chamber 4 is determined by using the thermometer electric output-temperature conversion table specific to this wafer 10, and
The electric output from the infrared radiation thermometers 14 and 15 is converted into temperature and read.

The wafer temperature controller 13 also determines to which stage the wafer 10 measured by the calibration stage 5 is transferred and placed, and the wafer temperature controller 13 places the wafer 10 on the stage by using the temperature conversion table. The temperature of the wafer 10 is measured.

After the emissivity calibration by the first infrared radiation thermometer 11 is completed, the wafer 10 is provided with the gate valve GV.
1 is opened and the wafer is transferred from the calibration chamber 2 to the wafer temperature adjustment chamber 3 and the temperature is measured by the second infrared radiation thermometer 14. From the measurement result, the temperature of the stage 6 is adjusted by the wafer temperature controller 13, and the temperature of the wafer 10 is adjusted to an arbitrary predetermined temperature. In this example, it was set to 100 ° C. After that, the wafer 10 has the gate valve GV2.
Is opened and conveyed to the stage 7 of the sputtering film forming chamber 4 in a vacuum state, the temperature is measured by the third infrared radiation thermometer 15, and the temperature of the stage 7 is adjusted to an arbitrary predetermined temperature based on the result. , The temperature of the wafer 10 is controlled to an arbitrary predetermined temperature to perform sputter film formation. In this example, 2
The film was set at 50 ° C. and the Al film was formed by sputtering. Then, for other wafers other than the wafer 10 (not shown), a thermometer electric output-temperature conversion table specific to another wafer other than the wafer 10 is sequentially created in the same procedure as that of the wafer 10 described above. It is used to measure and control the temperature of the wafer.

Although it is essentially necessary to calibrate each wafer, when an infrared radiation thermometer for detecting the wavelength of an opaque region is used for a material, a metal film on the wafer surface side is used. Since the emissivity does not change regardless of whether or not the emissivity is formed, the emissivity can be measured and corrected without using the shutter. Therefore, for all temperature measurements in each chamber in the vacuum processing apparatus, the measurement is similarly performed without using the shutter.

As a simple means for carrying between the chambers, for example, a carrying mechanism using a heat resistant belt made of silicone rubber or the like is used.

Next, referring to FIG. 2, an outline of the structure of the stage on which the wafer is mounted, a heating and cooling method, and a method for measuring the emissivity of the wafer will be described using an example of the wafer temperature adjusting stage 6.

(1) Structure of wafer temperature adjusting stage and heating / cooling method: The heater 1 is provided on the wafer temperature adjusting stage 6.
8 is built in, and the heat transfer gas flows into the space between the stage 6 and the wafer 10 in vacuum. Wafer 1
An opening window 19 for measuring the temperature of 0 by the infrared radiation thermometer 14 and a cylinder 16 for guiding the infrared light from the wafer to the infrared radiation thermometer and blocking stray light are connected. Window plates 27 and 28 made of a material that transmits infrared rays are attached to both ends. Further, the structure is such that the cylinder 16 itself is heated and cooled so as not to be a generation source of stray light. In order to further reduce the influence of stray light, mirror surface treatment of the inner wall of the cylinder 16 is possible. A shutter 21 is also provided. The shutter is
Any structure may be used as long as it has (1) a mirror surface state having infrared reflectance, and (2) a function of blocking stray light, for example, a structure in which it can be opened / closed in synchronization with a wafer temperature measurement timing, or Various configurations can be adopted, such as providing a fixed shutter in one region of the chamber and providing a mechanism for moving the wafer to the lower portion of the shutter during measurement. The means for bringing the wafer into contact with the stage may be of the electrostatic chuck type. Further, when the wafer is cooled, a cooling mechanism may be provided in the stage instead of the heater 18. In this method, since there is no physical contact on the wafer surface side, there is no contamination on the wafer surface side, and the generation of foreign matter can be suppressed to a low level.

(2) Measurement of emissivity: Next, a method of measuring the temperature of the wafer by the infrared radiation thermometer will be described. In this embodiment, infrared radiation thermometers 11, 14 and 15 are installed at the bottom of each stage to measure the temperature on the back side of the wafer, and stray light from inside each chamber is incident on the infrared radiation thermometer. To prevent this, a stray light blocking cylinder 16 is provided between the stage and the infrared radiation thermometer, and when measuring, a red light is placed close to the wafer 10 on the side opposite to the side of the wafer observed by the infrared radiation thermometer. Shutters 20, 21 and 22 each made of a member that reflects external light are arranged so as to be installed.

Next, it is effective to control the emissivity of the wafer on the calibration stage without controlling it to the ambient temperature (room temperature) so as not to adversely affect the processing in each subsequent stage. For that purpose, it is essential to measure the emissivity with a high S / N. The configuration of the calibration stage that enables accurate emissivity measurement with a high S / N ratio at the ambient temperature (room temperature) in the calibration stage will be described below with reference to FIG.

The wafer 10 is mounted on the calibration stage 5 by being held at an ambient temperature of 20 ° C. by an electrostatic chuck, and the inner surface of the stray light blocking cylinder 16 is a mirror surface. ) Has been eliminated. Further, at the time of measurement, a shutter 20 made of a member that reflects infrared light is installed close to the wafer 10 on the side opposite to the side observed by the infrared radiation thermometer. The generation of infrared radiant light (stray light) that affects the measurement is eliminated. Further, with respect to infrared radiation from the infrared radiation thermometer 11 itself, the thermometer is cooled and controlled to a low temperature, preferably 0 ° C. or lower. Similarly, the stray light blocking cylinder 16 and the shutter 20 are also controlled to a low temperature, and the stray light due to infrared radiation can be sufficiently ignored as compared with the infrared radiation from the wafer when the wafer 10 is at an ambient temperature (room temperature: usually around 20 ° C.). Try to keep it low.

Further, when highly accurate temperature measurement and control are required, for example, in the case of tungsten-CVD, the infrared emissivity measurement temperature is made equal to the CVD temperature in order to control the film formation rate with high accuracy. It realized the thermometer correction of, and in turn, enabled the temperature control. At a temperature of 200 ° C. or higher, a film thickness variation of ± 1% was obtained.

Example 2. Another embodiment of forming an aluminum film on the wafer 10 by sputtering using the sputtering apparatus 1 of FIG. 4 will be described.

The temperature of the wafer 10 is measured by the thermocouple 12 in the temperature calibration chamber 2 and the emissivity of the infrared radiation thermometer 11 is measured on the basis of this temperature. The emissivity correction unique to the wafer 10 and the output voltage of the thermometer are measured. Calculate the converted value between
Using the converted value of the thermometer output voltage and the temperature, the temperature is measured in the wafer temperature adjusting chamber 3 and the sputtering film forming chamber 4. Next, the wafer 10 is transferred to the load lock chamber 23, evacuated, and then transferred to the wafer temperature adjusting chamber 3. The wafer 10 transferred to the wafer temperature adjusting chamber 3 is heated by the lamp heater 25, at which time the temperature is measured by the infrared radiation thermometer 14 and controlled at 400 ° C. Next, the film is conveyed to the sputter film forming chamber 4. The wafer 10 is sputtered in the sputter deposition chamber 4 according to the temperature profile shown in FIG. The target 8 had a composition of 1% Si-3% Cu-Al.

The wafer temperature controller 13 also determines to which stage the wafer 10 measured by the calibration stage 5 is transferred and placed, and the wafer temperature controller 13 places the wafer 10 on the stage using the temperature conversion table. The temperature of the wafer 10 is measured. Then, the temperature of the stage 6 is adjusted by the wafer temperature controller 13 based on the temperature measurement result of each stage, and the temperature of the wafer 10 is adjusted to an arbitrary predetermined temperature.

First, the temperature of the wafer 10 is set to 230 ° C.
Control is performed to perform the first sputter film formation up to a film thickness of about 100 Å, the sputter is stopped there, and the wafer is transferred to the wafer temperature adjustment chamber 3. In the wafer temperature adjusting chamber 3, the temperature of the wafer 10 is controlled to be 300 ° C. by a lamp heater, and the Al obtained by the first sputtering film formation is used.
The crystal grains of the film are grown to improve the orientation and the like. Next,
The wafer is again transported to the sputter film forming chamber 4, and after setting the wafer temperature to about 400 ° C., the second sputter film forming is restarted to form a film having a film thickness of about 1 μm. As a result, an Al sputtered film having large crystal grains and good orientation can be obtained. Immediately after sputtering, the wafer is unloaded in chamber 2.
It is transported to 4 and rapidly cooled to about 50 ° C. As a result, the precipitation of Si and Cu in the Al sputtered film could be suppressed.

In the above embodiment, an example in which an Al thin film is formed on the surface of the wafer by sputtering is shown. However, since the temperature of the wafer can be controlled with high accuracy through the stage, crystallinity with good reproducibility can be obtained within the wafer. Therefore, it was possible to achieve a film having excellent quality. For example, when heating a thin film of several hundred liters at a heating temperature of 350 ° C. or higher, no improvement in crystallinity was obtained. Therefore, such a film forming method cannot be industrially realized without the present invention capable of knowing an accurate temperature.

The vacuum processing apparatus of the present invention is not limited to the above spatula apparatus, but can be used in a chemical vapor deposition (CVD) system.
It is needless to say that it can be applied to a film forming apparatus or the like according to the sition).

This is effective, for example, when a silicon wafer is used as a substrate and a tungsten film is formed on this wafer by a known method by CVD.

In all of the film forming apparatuses of this type, the accuracy of the temperature control of the wafer influences the quality of the film formed, and therefore the film forming apparatus of the present invention can sufficiently meet such requirements.

Although the film forming apparatus can be realized by using the vacuum processing chamber as the film forming processing chamber as in the above embodiment, the vacuum processing chamber can be used in addition to the film forming chamber, for example, dry etching processing such as plasma etching. The chamber can also be used as the chamber, and the temperature control of the wafer to be etched can be easily realized as in the above embodiment.

Example 3. An example of measuring the wafer temperature during the sputtering film formation and the lamp heating when the vacuum processing apparatus of the second embodiment is used for the sputtering film formation will be described below.

FIG. 6 shows changes with time in the temperature of the wafer during the sputtering film formation. It can be seen that a difference appears in the film formation temperature by changing the sputtering power.

FIG. 7 shows an example of measurement when the temperature of the wafer 10 is heated and controlled by heating the lamp in the wafer temperature adjusting chamber 3. As shown in FIG. 8, a stage for heating the lamp is provided with a heating lamp 25 above the wafer, and a shutter 21 is arranged between the wafer and the lamp so as to be close to the upper portion of the wafer only when measuring the temperature. The thermometer 14 is installed below the stage. Further, the shutter 21 is configured to be opened and closed in synchronization with the wafer temperature measurement timing, or a fixed shutter is provided in one region of the chamber,
Various configurations such as a mechanism for moving the wafer to the lower portion of the shutter at the time of measurement can be adopted. The broken line in FIG. 7 is the value at which the infrared light from the lamp is incident on the infrared radiation thermometer as stray light when the shutter 21 is not installed on the wafer 10 when the lamp is heated, and at the actual wafer temperature. Absent. Therefore, when the shutter 21 is inserted onto the wafer 10, stray light is removed as indicated by the solid line in the figure, and the measured value becomes smaller. This value becomes the actual wafer temperature. Thus, in the case of heating the lamp, the shutter 21 also has an effect of removing stray light from the lamp. When the lamp is heated, the shutter 21 is installed at a position apart from the wafer, and does not hinder the lamp heating. 9 and 10 show a method for controlling the temperature of a wafer during heating of a lamp. The wafer temperature T ₀ before the heating is started and the temperature T ₁ after a lapse of a known time t1 after the heating is started are infrared radiation temperatures. measured by meter determines the rate of temperature increase up there, thereafter assuming a constant heating rate, the desired heating temperature (set temperature; T _S) to determine the remaining heating time t2 to heat up. After the heating is completed, the temperature T ₂ is measured. As a result, as shown in FIG. 10, it can be controlled with an accuracy of ± 2.5 ° C. for the settings of 300 ° C. and 400 ° C.

Example 4. Regarding the emissivity correction method, thermometer output-temperature conversion table creation method, and wafer temperature measurement method during emissivity measurement by the calibration stage, FIG.
1 to 14 and Tables 1 to 5 will be described.

FIG. 12 is a block diagram of an infrared radiation thermometer which has been conventionally used. The output from the infrared radiation thermometer 30 is proportional to the radiant energy, and has a non-linear relationship with the actual temperature. For this reason, the linearizer 38 for linearizing the output from the infrared radiation thermometer 30 is necessary. Data for the linearization processing by the linearizer can be obtained by numerical calculation from a well-known black body radiation formula. Table 1 summarizes the relationship between the output signal voltage of the infrared radiation thermometer and the measured temperature based on the results of such calculations.

[0082]

[Table 1]

An amplifier 36 is provided in front of the linearizer 38, and the amplifier 36 has a gain adjusting function 37. Emissivity is a measure of how easily an object emits radiation according to temperature. For example, for an object having an emissivity of 1, temperature can be measured by setting the gain of the amplifier to 1.

If the emissivity is 0.5, the temperature can be measured by setting the gain of the amplifier to 2. That is, with respect to the emissivity, the overall sensitivity is adjusted before performing the linearization.

In the case where the infrared emissivity changes with temperature, it is necessary to change the gain of the amplifier 36 in FIG. 12 so as to follow the temperature. An embodiment according to the present invention will be described in more detail.

FIG. 11 shows an example of using a computer for signal processing of the thermometer shown in FIG. 12, and linearization processing is also performed by digital calculation.

The analog signal from the infrared radiation thermometer 30 is converted into a digital signal by the A / D converter 31 and taken into the computer 32. The result of the arithmetic processing is displayed or recorded through the display 33, the floppy disk 34, and the analog signal for the recorder via the D / A converter 35.

Next, the temperature measurement will be described with reference to the flowchart of FIG. 13 and FIG.

First, when the emissivity of the wafer is measured at a known temperature by the calibration stage and the measured temperature is measured at T ₀ , emissivity = ε ₀ is obtained. Next, it is known that the emissivity at Tmax becomes constant at a high temperature of 500 ° C. or higher in a semiconductor such as a Si wafer because it metallizes and converges to ε _max . The relationship between the wafer temperature and the infrared emissivity is obtained as a function of temperature ε (T) by the computer 32 by calculation of linear interpolation. An example of this is shown in Table 2.
Shown in.

[0090]

[Table 2]

Based on the emissivity characteristic peculiar to the wafer, a conversion table of the thermometer output and the temperature peculiar to the wafer is obtained by the computer 32.
Created by. This conversion table is created as a linear conversion table by calculating the emissivity in 0.01 steps from the theory of black body radiation. For the emissivity of the wafer, the linearized data is picked up from the table 2 at the wafer temperature of 1.0 ° C., and the final conversion table specific to the wafer is made as shown in Table 5. For the measurement of this wafer in the vacuum processing apparatus 1, the temperature is measured by sequentially referring to this conversion table.

Next, the calculation process when the wafer-specific thermometer output-temperature conversion table shown in Table 5 is created will be specifically described with reference to Tables 2, 3, 4, and 5. However, the numerical values are virtual.

[0093]

[Table 3]

[0094]

[Table 4]

[0095]

[Table 5]

First, the method of calculating the emissivity will be described. FIG. 14 shows the result of another measurement of the temperature change of the emissivity of the wafer whose temperature is to be measured. For example, measuring the emissivity of the wafer at 150 ° C.,
When 0.3 was obtained, linear interpolation was performed between the measured emissivity of 0.3 at 150 ° C and the value of emissivity of 0.5 (500 ° C), which is constant at high temperature, and shown in Table 2. Such emissivity can be obtained. Next, the relationship between the wafer thermometer output and the temperature is calculated from the relationship between the emissivity and the black body thermometer output and the temperature, and the emissivity shown in Tables 3 and 4 is, for example, 0.30 and 0.31, respectively. The relationship between the thermometer output at the time of and the converted temperature can be obtained. When the emissivity is 0.30 and 0.31, compared with the black body shown in Table 1, the wafer has an output of an infrared radiation thermometer that gives the same measurement temperature and the voltage value is simply 0.3.
It is 0, 0.31 times. This is natural from the definition of object radiation.

Next, the arithmetic processing in the computer will be described below.

It can be seen from Table 2 that the emissivity of the wafer should be 0.3 in the range of 150 ° C to 151 ° C.
The output voltage of the thermometer which gives 150 ° C is 0.51 from Table 3.
It is 0V. Also, from Table 2, the emissivity is 0.3 at 152 ° C.
Since it is 10, it can be seen from Table 4 that the output voltage of the thermometer which gives 152 ° C. is 0.530V.

The above operation is performed within the temperature range to be measured, and as an example, as shown in Table 5, the relationship between the output voltage of the radiation thermometer and the measured temperature is newly summarized in the table.

If the thermometer output voltage and the temperature as shown in Table 5 are converted within the temperature range to be measured, the ambient temperature or the environment can be changed even for a semiconductor wafer whose emissivity greatly changes as shown in FIG. Accurate measurement can be performed over the entire temperature range to be measured by only measuring the emissivity at one low temperature close to the temperature.

Example 5. Hereinafter, a method of measuring the emissivity of a Si wafer as a wafer will be described with reference to FIG.

FIG. 15 is a conceptual diagram showing a method for measuring the emissivity of a wafer. A wafer 10 is placed on the wafer temperature calibration stage 5. A specular reflector 40 is installed above the wafer 10. The specular reflector 40 must have a sufficiently high reflectance in the intended measurement wavelength range.

A beam splitter 41 is installed below the wafer temperature calibration stage 5. Reference light generator 42
In this example, an output light mainly having a wavelength of about 10 μm can be obtained by using an appropriate filter.
The beam 3 passes through the beam splitter 41 and enters the wafer 10. The reflected light 44 from the wafer 10 is bent by the beam splitter 41 and enters the photodetector 45.

The light radiated or transmitted above the wafer 10 is reflected by the specular reflector 40, and all of it is returned to the wafer 10.

In general, the emissivity is equal to the absorptance α when the intensity of incident light is Io, the intensity of transmitted light It, and the intensity of reflected light Ir are known, and is expressed by the following equation.

Α = (Io-It-Ir) / Io In the example shown in FIG. 14, the transmitted light I due to the specular reflector 40 is used.
t = 0. Therefore, the absorptance or the emissivity can be calculated by knowing the incident light intensity Io and the reflected light intensity Ir on the wafer 10. To apply the emissivity thus known to, for example, a wafer such as the wafer 10 before vapor deposition, the temperature is measured, for example, from the back surface with an infrared radiation thermometer, and at that time, a mirror surface is formed on the front surface side of the wafer 10. Install a reflector. Since the metal film itself is the specular reflector during or after the vapor deposition of the metal film, the specular reflector 40 is unnecessary.

Example 6. A sixth embodiment of the present invention will be described with reference to FIGS.

FIG. 16 is a schematic configuration diagram (plan view) in which the vacuum processing apparatus of the present invention is applied to a sputtering film forming apparatus. In this embodiment, a silicon (Si) wafer (hereinafter referred to as a wafer) is used as a film formation target, and an Al or Al alloy thin film (hereinafter referred to as an Al thin film or an Al film) is formed thereon by sputtering as a typical example. explain. The vacuum processing apparatus 50 of the present invention includes a wafer loading chamber 51 and an unloading chamber 5
2, a vacuum bake chamber 53 as each vacuum processing chamber for performing the vacuum processing, and a sputter etching chamber 54 for removing a natural oxide film or the like on the surface which causes a wiring failure before the Al film is formed. And sputter deposition chamber 55 for depositing Al film
And a transfer chamber 57 having a transfer mechanism (for example, an articulated transfer robot) for transferring the wafer 10 to each vacuum processing chamber and transferring the wafer 10 back from each vacuum processing chamber after each vacuum processing. It is a composition. The vacuum processing chamber and the transfer chamber are respectively provided with gate valves 58, 59, 6
0, 61, 62 are connected and independent. Also,
An exhaust system (not shown) is connected to each chamber and can be maintained in a predetermined vacuum state. An infrared lamp heater (not shown) for heating the wafer is disposed in the vacuum bake chamber 53, and a predetermined gas is introduced into the sputter etch chamber 54 and the sputter film forming chamber 55 from a gas inlet (not shown). It is configured so that the environment in which plasma is generated by a predetermined discharge can be set. Further, the sputter etching chamber 54 and the sputter film forming chamber 55 are provided with heating means. In the configuration of this embodiment, the temperature is not measured during the treatment in those chambers, but the heating means is set under constant heating conditions. The temperature measurement in the transfer chamber 57 is performed to measure the temperature of the wafer before and after the wafer is put into the vacuum film forming chamber. Furthermore, the load chamber 51 and the unload chamber 52 are
A gas (for example, nitrogen gas or air) introduction mechanism (not shown) for returning the both chambers from the vacuum state to the atmospheric pressure for loading and unloading the wafer, and doors 63, 64 for loading and unloading, respectively. Be prepared for.

FIG. 17 shows the vacuum processing apparatus 50 shown in FIG.
2 is a cross-sectional view taken along line AA ′ of FIG.

In this embodiment, the position where the infrared radiation thermometer 65 is installed in the transfer chamber 57 is the temperature measurement position, and the temperature measurement position is fixed to the transfer chamber 57. FIG.
Shows a more detailed description of the optical system at the temperature measurement position.

As shown in FIG. 18, an opening window 67 for measuring the temperature of the wafer 10 with an infrared radiation thermometer 65 and a stray light blocking cylinder 68 are connected to the temperature measuring optical path 66. The structure is water-cooled so that it does not become a source of stray light when it is heated. In order to further reduce the influence of stray light, it is possible to cool the inner wall of the cylinder 68 and then blackbody it. The infrared radiation thermometer 65 is installed in the atmosphere.

For this reason, the optical path 66 must pass through the boundary between the atmosphere and vacuum. The part 67 is an observation window for this purpose, and the observation window 67 is provided with a window plate 69 that separates atmospheric pressure from vacuum. The window plate 69 is made of a material that efficiently transmits infrared rays, such as barium fluoride, calcium fluoride, ZnSe (zinc selenium), or the like. Since the window plate 69 must withstand atmospheric pressure, a window plate having a thickness of about 5 mm is usually used to secure the strength. Further, in order to prevent stray light from the surroundings from entering as noise of detection by the infrared radiation thermometer 65, the wafer 1 is placed on the front side 10-1 of the wafer 10 at the temperature measurement position.
The reflector 70 is installed close to 0 by about 1 to 3 mm with its reflection surface facing the wafer 10. That is, the size of the reflector 70 is such that the infrared radiation from the wafer surface can be reflected by the mirror surface of the reflector 70 and sufficiently incident on the region of the observation optical path 66. -1 is so close that stray light does not enter as noise of the detection of the infrared radiation thermometer 65.

The reflector 70 has (1) an infrared reflectance in a mirror state. (2) Any structure and material may be used as long as it has a function of blocking stray light.

FIG. 19 shows an example of the process flow performed in this embodiment.

The wafer introduced into the vacuum from the load chamber 51 is degassed and baked in the vacuum bake chamber 53, and the sputter etching chamber 54 is cleaned after the natural oxide film on the wafer surface is removed. At 55, an Al film is formed on the front surface side 10-1 of the wafer by the sputtering method, and is taken out from the unload chamber 52 to the atmosphere. In order to transfer the wafer to each of the vacuum processing chambers, the wafer must be transferred to and from each of the vacuum processing chambers without fail.
And at that time, that is, before and after performing each vacuum processing, the temperature of the wafer is measured at the temperature measuring position provided in the transfer chamber 57.

The door 63 was opened in the load chamber 51 under atmospheric pressure to introduce one or more wafers (process 81).
After that, the load chamber 51 is evacuated to a predetermined pressure.
After that, the gate valve 58 is opened and the transfer robot 72 is set to 1
The first wafer is taken into the transfer chamber, transferred to the temperature measurement position, and the temperature is measured (process 82).

The apparent emissivity of a wafer varies from wafer to wafer depending on the type of semiconductor product and the structure and type of thin film formed in the manufacturing process, that is, the process performed prior to the main sputtering film forming process. Different to. Therefore, this infrared radiation thermometer is
The emissivity is calibrated in advance for each sheet. By the way, the case of emissivity = 1 is a perfect blackbody. Si wafers have a relatively low apparent emissivity (0.2-0.5). Since the Si wafer transmits infrared light in a wide range of infrared wavelengths, the infrared light transmitted from the surface side 10-1 is infrared as stray light when the metal film (Al film) is not yet formed on the wafer. It enters the radiation thermometer and becomes a noise component. In the present invention, the reflector 70 is placed close to the wafer, and the stray light blocking cylinder 68 is used.
The stray light does not enter the infrared radiation thermometer because of the provision of, and stable temperature measurement without stray light noise becomes possible. Furthermore, since the reflector 70 can reflect the infrared light from the front surface 10-1 of the wafer to the back surface 10-2, the emissivity of the back surface of the wafer can be apparently increased, so that a high signal /
Temperature can be measured by the noise ratio.

Next, the wafer is transferred to the vacuum bake chamber 53, the wafer is heated in the vacuum bake chamber 53 to be degassed and baked (process 83), and then the transfer chamber 57 is again used.
Then, the temperature of the wafer after vacuum baking is measured again by the same method as described above (process 84). The temperature measured at this time is the wafer temperature before the next sputter etching process. Then, after the wafer is transported to the sputter etch chamber and subjected to the sputter etch process (process 85), the wafer is also transported back to the transport chamber 57 and the temperature of the wafer after the sputter etch is measured again (process 86). ). Then, this temperature is again set as the wafer temperature before the Al film is formed by sputtering.

Next, the wafer is transferred to the sputter film forming chamber 55 to form an Al film (process 87), and then the wafer is transferred back to the transfer chamber 57 and after the Al film is formed at the temperature measuring position. The wafer temperature is measured by the same method as described above (process 88).

After depositing the Al metal on the surface of the Si wafer, the infrared light radiated from the front side 10-1 of the wafer is reflected by the deposited Al film and transmitted through the wafer to the back side 10-2 of the wafer. Since it is radiated and added to the original radiation from the wafer back surface 10-2, the apparent emissivity from the wafer back surface 10-2 is significantly increased. Therefore, in the conventional temperature measurement using the infrared radiation thermometer, the emissivity calibrated before the film forming process cannot be used due to the subsequent film forming process. However, according to the present invention, even if the Al film is not formed on the wafer, the reflector 70 has a reflection characteristic equivalent to that of the Al metal film to be formed on the front surface 10-1 of the wafer. The temperature can be measured without changing the emissivity of the wafer originally calibrated in all steps of the process flow shown in FIG. 19 before and after film formation.

As described above, the Al film is a very good reflector, and in other words, it shows that the emissivity is very small (about 0.01 to 0.15). That is, since the emissivity on the front side of the wafer becomes extremely small after the Al film is formed, it is almost impossible to obtain infrared radiation sufficient for temperature measurement. Therefore, contrary to the present invention, the wafer front side 10
When measuring the temperature from -1 with an infrared radiation thermometer, the emissivity changes significantly before and after the Al metal film is formed. Cannot be used. Moreover, in this case, the apparent emissivity changes irrespective of whether the reflector 70 is used or not, so that it becomes very difficult to measure the temperature on the side where the film is formed. On the other hand, in the present invention, the measurement is performed from the back surface of the wafer as described above, and the problem is solved by using the reflector 70.

After the temperature measurement after forming the Al film, the wafer is transferred to the unload chamber 52, and then a gas such as air or nitrogen gas is introduced only into the unload chamber 52 to bring the unload chamber 52 to the atmospheric pressure. After that, the door 64 is opened and the wafer is taken out from the vacuum processing apparatus 50 (processing 89). Then, the temperature of the next wafer is repeatedly measured and the vacuum processing is performed in the same manner as described above.

However, the process flow shown in the present invention is not limited to the one embodiment described above, and various forms can be changed.
That is, in the case of forming a laminated wiring film structure or the like, the present invention can be easily applied to the addition of one or more film formation processing chambers in addition to the flow shown in FIG.

In addition to the process shown in FIG. 19, the vacuum process may be a cooling process for cooling the wafer to a predetermined temperature after the heating process, the sputter etch cleaning process, the sputter film forming process, and the like. The present invention can be applied without any problems.

Further, in the above-mentioned embodiment, the Al sputter film formation is described as an example, but also in the tungsten-CVD process or the process of forming a multi-layered multilayer structure of a plurality of metal films with the tungsten-CVD process. The present invention can be applied without departing from the spirit of the present invention.

In addition to the above-mentioned silicon wafer, the present invention also employs a so-called glass wafer containing silicon oxide, aluminum oxide or the like as a main component, a material exhibiting transparent or translucent characteristics with respect to infrared wavelengths. It can also be applied to CaAs (gallium arsenide) wafers and the like.

Further, in the above embodiment, the temperature measured in the transfer chamber 57 is directly treated as the temperature before and after the vacuum processing, but it has different heat dissipation rate depending on the speed of the transfer robot and the emissivity of the wafer itself. Therefore, strictly speaking, the temperature measured at the temperature measurement position in the transfer chamber 57 and the vacuum processing start or end temperature are different. For this process in which the difference in temperature is a problem, temperature measurement is performed for a certain time at the temperature measurement position of the transfer chamber, the heat dissipation rate is calculated, and the vacuum processing start or end temperature is extrapolated from the value. It is possible to measure the temperature with higher accuracy.

In the above embodiment, Al is formed on the surface of the Si wafer.
Although an example of forming a thin film by sputtering has been shown, the wafer temperature can be measured with high accuracy, so that fluctuations in the wafer temperature that cause a decrease in yield can be quickly detected, so that a high quality film can be finally formed. We were able to achieve it with a high yield.

[0129]

As described above, according to the present invention, it is possible to accurately measure and control the temperature of a substrate in a vacuum, and to realize a vacuum processing apparatus capable of accurately controlling the temperature of the substrate. In addition, by applying it to a film forming apparatus, it is possible to easily control the temperature before and after the film formation and during the film formation, which requires accurate temperature control, and thus it is possible to form a high quality film.

Furthermore, according to the present invention, a vacuum processing apparatus capable of accurately controlling the temperature of a substrate is realized particularly in a vacuum processing apparatus of a multi-channel type, and the formation of a high quality thin film can be continuously controlled. The final product defect rate can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional block configuration diagram for schematically explaining a vacuum processing apparatus showing an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional configuration diagram showing an example of a wafer temperature adjustment stage.

FIG. 3 is a schematic sectional configuration diagram showing an example of a calibration stage.

FIG. 4 is a schematic configuration diagram of a vacuum processing apparatus showing another embodiment of the present invention.

FIG. 5 is an explanatory diagram showing one temperature profile during film formation.

FIG. 6 is a diagram showing an example of measuring temperature rise characteristics during Al sputtering.

FIG. 7 is a diagram showing an example of measuring a wafer temperature by heating a lamp heater.

FIG. 8 is a schematic sectional configuration diagram of a lamp heating stage.

FIG. 9 is a diagram showing a wafer temperature control method in lamp heating.

FIG. 10 is a diagram showing a temperature at the end of heating with respect to a heating set temperature.

FIG. 11 is a schematic configuration diagram of an infrared radiation thermometer of the present invention.

FIG. 12 is a schematic configuration diagram of a conventional infrared radiation thermometer.

FIG. 13 is a flow chart for creating an emissivity measurement and thermometer output conversion table.

FIG. 14 is a diagram showing a result of measuring the emissivity of a wafer.

FIG. 15 is a configuration diagram of an apparatus including means for calibrating the emissivity of a wafer according to an embodiment of the present invention.

FIG. 16 is a plan view for explaining an embodiment of the vacuum processing apparatus according to the present invention.

FIG. 17 is a diagram illustrating a cross-sectional structure taken along the line AA ′ of the vacuum processing apparatus of FIG.

FIG. 18 is a diagram illustrating an optical system for measuring a wafer temperature, which is provided in a transfer chamber of a vacuum processing apparatus according to the present invention.

FIG. 19 is a diagram illustrating an example of a vacuum processing process flow when the vacuum processing apparatus according to the present invention is used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Vacuum processing apparatus, 2 ... Wafer temperature calibration chamber, 3 ... Wafer temperature adjustment chamber, 4 ... Sputter deposition chamber, 5 ... Wafer temperature calibration stage, 6 ... Wafer temperature adjustment stage, 7, 7-1 ... Sputter stage, 8 ... Target, 9 ... Sputtering electrode, 10 ... Base (wafer), 10-1 ... Wafer front side (deposition surface of metal film (Al etc.)), 10-2 ... Wafer back side, 11, 14, 15 ... Infrared radiation Thermometer, 13 ... Base temperature controller, 16 ... Stray light blocking cylinder, 18 ... Heat block internal heater, 19 ... Open window, 20-22 ... Shutter, 23 ... Load lock chamber, 24 ... Unload chamber, 25 ... Lamp Heater, 27 ... Lower window plate, 28 ... Upper window plate, 40 ... Specular reflector, 41 ... Beam splitter, 42 ... Calibration reference infrared light generator, 43 ... Reference incident light, 4 ... reflected light, 45 ... reflected infrared light detector, 50 ... multi-chamber type sputtering device, 51 ... load chamber, 52 ... unload chamber, 53 ... vacuum bake chamber, 54 ... sputter etch chamber, 55 ... sputter chamber, 57 ... Transfer chamber, 58 to 62 ... Gate valve, 63 ... Door for loading wafer, 64 ... Door for unloading wafer, 65 ... Infrared radiation thermometer, 66 ... Optical path for observation of infrared radiation thermometer. 67 ... View window between atmosphere and vacuum, 68 ... Stray light blocking cylinder, 69 ... Infrared light path window material separating air and vacuum, 70 ... Reflector, 71 ... Vacuum chamber wall, 72 ... Transfer robot,

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location H01L 21/66 T 7352-4M // H01L 21/203 Z 8422-4M (72) Inventor Yujioka Yoneoka 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa, Ltd.Hitachi, Ltd., Production Engineering Laboratory (72) Inventor Susumu Susumu, 292, Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa, Ltd., Hitachi, Ltd., Production Engineering Laboratory (72) Inventor Nishitani Eisuke 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa, Ltd.Production Technology Research Institute, Hitachi, Ltd. (72) Inventor Satoshi Kishimoto 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Ltd., Production Engineering Laboratory, Hitachi, Ltd. (72) Inventor Tokio Kato 5-20-1 Kamimizumoto-cho, Kodaira-shi, Tokyo Stock company Hitachi Semiconductor Design and Development Center

Claims (41)

[Claims] 1. A temperature calibration stage for controlling a substrate to an ambient temperature to measure an infrared emissivity; a first infrared radiation thermometer for measuring radiant heat of a substrate; and a first infrared radiation thermometer for the first infrared radiation thermometer. Means for calculating an emissivity from the output based on a known temperature of the substrate and calculating an infrared sensitivity correction value for correctly displaying the temperature of the substrate by the first infrared radiation thermometer; A vacuum processing chamber provided with a stage on which different substrates are placed, a means for heating or cooling the substrates to a predetermined set temperature, and a means for performing vacuum processing on the substrates; a second for measuring radiant heat of the substrates And the true temperature of the substrate placed in the vacuum processing chamber based on the infrared sensitivity correction value obtained by the temperature calibration chamber from the output of the second infrared radiation thermometer. Means for calculating; and a shutter mechanism which is disposed close to the substrate on each of the above stages and whose main surface is constituted by a member that is sufficiently mirror surface for the measurement wavelength of the infrared radiation thermometer. Vacuum processing equipment. 2. A temperature calibration stage for measuring the infrared emissivity of a substrate; a first infrared radiation thermometer for measuring the radiant heat of the substrate; and a known output of the first infrared radiation thermometer for the substrate. Means for calculating an emissivity based on the temperature of the first infrared radiation thermometer, and calculating an infrared sensitivity correction value for correctly displaying the temperature of the substrate by the first infrared radiation thermometer;
A stage on which a substrate which is the same as or different from the stage is placed, a means for heating or cooling the substrate to a predetermined set temperature, and a vacuum processing chamber provided with means for performing vacuum processing on the substrate; Radiant heat of the substrate A second infrared radiation thermometer for measuring the true temperature of the substrate placed in the vacuum processing chamber based on the infrared sensitivity correction value obtained by the temperature calibration stage from the output of the second infrared radiation thermometer. A vacuum processing apparatus comprising: means for calculating. 3. The vacuum processing apparatus comprises a plurality of vacuum processing tanks for processing a plurality of substrates. Temperature measurement when an Nth substrate is subjected to a predetermined processing in an Mth vacuum processing tank. Is based on the emissivity as a function of temperature determined in advance by measurement and calculation for the Nth substrate so that the electric output of the thermometer provided in the Mth vacuum processing tank is converted into temperature. The vacuum processing apparatus according to claim 1 or 2, wherein the vacuum processing apparatus is provided. 4. An observation hole provided in at least one of the respective stages for observing the temperature of the substrate by the infrared radiation thermometer, and an infrared radiation thermometer for infrared light from the substrate. 4. The vacuum processing apparatus according to claim 1, further comprising: an optical path for leading to the substrate and means for bringing the substrate into contact with the member by an electrostatic force line generated from the member of the stage. 5. An observation hole provided in at least one of the respective stages for observing the temperature of the substrate by the infrared radiation thermometer, and infrared radiation thermometer for infrared light from the substrate. , An optical path for guiding the temperature to the substrate, and a gas introduction means for filling a predetermined gas with a predetermined gas pressure in the space of the stage in contact with the substrate, and measuring the infrared radiation thermometer. The temperature control means comprising a first window plate for partitioning a vacuum atmosphere between the substrate side of the observation hole and the infrared radiation thermometer side made of a material substantially transparent to the wavelength. ~ The vacuum processing device according to 4. 6. The first and second infrared radiation thermometers,
The vacuum processing apparatus according to any one of claims 1 to 5, wherein measurement is performed at the same wavelength in the infrared region. 7. The vacuum processing apparatus according to claim 1, wherein means for controlling the substrate on said temperature calibration stage to a known predetermined temperature is provided outside said vacuum processing chamber. 8. The vacuum processing apparatus according to claim 1, wherein the temperature calibration stage is arranged in a replacement atmosphere with the atmosphere. 9. The means for controlling the temperature of the substrate on the temperature calibration stage to a known predetermined temperature comprises a means for bringing the substrate into contact with a member having a larger heat capacity than the substrate. Vacuum processing equipment. 10. The means for bringing the substrate into contact with a member having a larger heat capacity than the substrate comprises means for evacuating the space where the substrate contacts the member to a vacuum. 9. The vacuum processing apparatus according to 9. 11. The means for bringing the substrate of the calibration stage into contact with a member having a larger heat capacity than the substrate comprises means for bringing the substrate into contact with the member by the lines of electrostatic force generated by the member. 10. The vacuum processing apparatus according to 10. 12. A means for controlling the temperature of the substrate on the temperature calibration stage to a known predetermined temperature is in a vacuum processing chamber, and means for physically contacting the substrate with a member having a larger heat capacity than the substrate, The vacuum processing apparatus according to any one of claims 1 to 2, 3, 4, and 11, wherein means for enclosing a gas having a pressure of 5 Pascal or more is provided in a space where the base body and the member are in contact with each other. 13. The means for controlling the temperature of the substrate on the temperature calibration stage to a known predetermined temperature is in a vacuum processing chamber, and means for contacting the substrate with a member having a larger heat capacity than the substrate by lines of electrostatic force. The vacuum processing apparatus according to claim 1, wherein the vacuum processing apparatus is provided. 14. The means for bringing the substrate of the calibration stage into contact with a member having a larger heat capacity than the substrate comprises means for bringing the substrate into contact with the member by the lines of electrostatic force generated by the member. 13. The vacuum processing apparatus according to 13. 15. The vacuum processing apparatus according to claim 1, wherein at least one of the means for heating the substrate in the vacuum processing chamber comprises a lamp heating means. 16. At least one of the stages in the vacuum processing chamber has a temperature which is an amount deviated from a predetermined set temperature in the vacuum processing chamber from the temperature of the substrate obtained from the output of a second infrared radiation thermometer. The vacuum processing apparatus according to any one of claims 1, 2, 3, 4, 5 or 15, comprising temperature control means for adjusting the temperature. 17. A temperature calibration stage capable of maintaining the substrate at a known temperature for measuring an infrared emissivity of the substrate; a first infrared radiation thermometer for measuring radiant heat of the substrate; the first infrared ray. Means for calculating an emissivity from the output of the radiation thermometer based on a known temperature of the substrate, and calculating an infrared sensitivity correction value for correctly displaying the temperature of the substrate by the first infrared radiation thermometer; A stage on which a substrate identical to or different from the stage is placed, and means for heating or cooling the substrate to a predetermined set temperature,
A vacuum processing chamber provided with means for performing vacuum processing on the substrate; a second infrared radiation thermometer for measuring radiant heat of the substrate; and a temperature calibration stage obtained from the output of the second infrared radiation thermometer Means for calculating the true temperature of the substrate placed in the vacuum processing chamber based on the infrared sensitivity correction value; at least disposed close to the substrate on the calibration stage and sufficient for the measurement wavelength of the infrared radiation thermometer And a shutter mechanism whose main surface is composed of a member that is a mirror surface. 18. The sputtering film forming apparatus according to claim 17, wherein the vacuum film forming processing chamber comprises a vacuum film forming processing chamber capable of forming a thin film under a predetermined condition by a sputtering method. 19. The CVD film forming apparatus according to claim 17, wherein the vacuum film forming processing chamber comprises a vacuum film forming processing chamber capable of forming a thin film under a predetermined condition by a CVD method. 20. A predetermined substrate for film forming processing is placed on a stage in a substrate temperature calibration chamber, the infrared emissivity of the substrate is measured, and then the substrate is transferred to a stage in a vacuum film forming chamber. And controlling the temperature to a predetermined first film-forming set temperature to start film-forming, and then setting the substrate temperature to the first
Of the second film forming temperature, which is higher than the film forming set temperature, to form a film with a predetermined thickness, and after the film forming is completed, the film is rapidly cooled to the first film forming set temperature or less. A film forming method using the film forming apparatus according to claim 17. 21. A predetermined substrate for film forming processing is placed on a stage in a substrate temperature calibration chamber so that the temperature of the substrate becomes the same as the set temperature at the time of film forming in the vacuum processing chamber. Controlling, measuring the infrared emissivity, and then transporting the substrate to a stage in a vacuum film forming chamber to control the film at a predetermined set temperature and perform film formation.
A film forming method using the film forming apparatus according to 7. 22. The means for contacting the substrate and the stage, which is placed on the stage in the substrate temperature calibration chamber and is controlled to be the same as the substrate temperature at the time of film formation, is composed of a stage member and a substrate. The film forming method according to claim 21, which is configured by a film forming apparatus according to claim 17, which is configured to have a means for contacting by an electrostatic force line generated by the member. 23. The film forming method according to claim 21, wherein the calibration temperature and the film forming temperature are 200 ° C. or higher. 24. A substrate whose temperature is to be measured, an infrared radiation thermometer for measuring the temperature of the substrate, and a surface opposite to the surface of the substrate whose temperature is measured by the infrared radiation thermometer,
A method for measuring a substrate temperature, in which a mirror surface having a sufficient reflectance for an infrared wavelength to be measured is installed substantially perpendicular to an optical axis measured by the infrared radiation thermometer and the temperature of the substrate is measured. 25. The means for calculating the infrared sensitivity correction value of the first infrared radiation thermometer in the calibration stage knows the infrared emissivity of the substrate and determines the emissivity change of the substrate as a function of temperature. A method for measuring the temperature of a semiconductor substrate by an infrared radiation thermometer, which creates a radiance output of the substrate and a temperature conversion table from this, and measures the temperature using this table. 26. The infrared radiation temperature according to claim 25, wherein the emissivity of said substrate is interpolated from the value of the emissivity between infrared emissivity at two or more different temperatures to obtain it as a function of temperature. Method for measuring the temperature of a semiconductor substrate by a meter. 27. As the infrared emissivity at the different temperatures, the emissivity is measured at a temperature of at least one point of the object, and the emissivity is higher than the emissivity measurement temperature. 3. The method according to claim 2, characterized in that
5. A method for measuring the temperature of a semiconductor substrate by the infrared radiation thermometer according to any of 5, 26. 28. In the substrate temperature measuring means for detecting the temperature of the substrate by the infrared radiation thermometer, a reflector for reflecting the infrared wavelength region to be measured is provided on one surface of the substrate, A means and a device for measuring the emissivity of a substrate, wherein the emissivity of the substrate is known. 29. A vacuum processing chamber having means for heating a substrate to a predetermined set temperature, a vacuum film forming processing chamber having means for performing vacuum film forming processing on the substrate, and the vacuum processing chamber or the vacuum. A transport chamber having a transport mechanism for transporting the substrate to the film formation processing chamber, at least one infrared radiation thermometer for measuring radiant heat of the substrate in the transport chamber, and a measurement wavelength of the infrared radiation thermometer. On the other hand, a vacuum processing apparatus, characterized in that it has a reflector provided to face the base body that reflects radiant heat with a member that is a mirror surface. 30. The infrared radiation thermometer is provided on the opposite side of the surface of the substrate to be subjected to the vacuum treatment, and the reflector is provided in a direction opposite to the surface of the substrate to be subjected to the vacuum treatment. 30. The vacuum processing apparatus according to claim 29, wherein: 31. A vacuum processing chamber having means for heating or cooling the substrate to a predetermined set temperature, a vacuum etching processing chamber having means for performing vacuum etching processing on the substrate, and the vacuum processing chamber or the vacuum. A transport chamber having a transport mechanism for transporting the substrate to the etching chamber, at least one infrared radiation thermometer for measuring the radiant heat of the substrate in the transport chamber, and a measurement wavelength of the infrared radiation thermometer. And a reflector provided so as to face the substrate that reflects radiant heat with a member that is a mirror surface. 32. The infrared radiation thermometer is provided on the opposite side of the surface of the substrate to be subjected to the vacuum treatment, and the reflector is provided in a direction opposite to the surface of the substrate to be subjected to the vacuum treatment. 32. The vacuum processing apparatus according to claim 31, wherein. 33. A multi-chamber type vacuum processing apparatus comprising: a plurality of vacuum processing chambers for performing vacuum processing on a substrate; and a transfer chamber having a transfer mechanism for transferring the substrates to each vacuum processing chamber. At least one infrared radiation thermometer for measuring the radiant heat of the substrate in the transfer chamber, and the substrate for reflecting the radiant heat from the substrate composed of a member that is a mirror surface with respect to the measurement wavelength of the infrared radiation thermometer, facing the substrate. A multi-chamber type vacuum processing device having a reflector provided by the above. 34. The infrared radiation thermometer is provided on the opposite side of the surface of the substrate to be subjected to the vacuum treatment, and the reflector is provided in a direction opposite to the surface of the substrate to be subjected to the vacuum treatment. 34. The vacuum processing apparatus according to claim 33, wherein: 35. The substrate is loaded into a vacuum device, the substrate is moved to a transfer chamber, the substrate is then moved to a vacuum processing chamber, and the substrate is subjected to predetermined vacuum processing in the vacuum processing chamber, A film forming method comprising the steps of: cleaning the substrate, forming a thin film on the substrate, and moving the substrate again to the transfer chamber after the vacuum treatment. The temperature of the substrate is measured in the transfer chamber.
A film forming method using the vacuum processing apparatus according to 9, 31, 33. 36. The film forming method according to claim 35, wherein an infrared radiation thermometer is used for measuring the temperature in the transfer chamber. 37. When measuring the temperature in the transfer chamber, a reflector for reflecting radiant heat from a base body made of a member which is a mirror surface against the measurement wavelength of the infrared radiation thermometer opposes the base body. The film forming method according to claim 35, wherein the film forming method is provided as follows. 38. Loading a substrate, moving the substrate to a first vacuum processing chamber, heating the substrate in the first vacuum processing chamber, and transferring the substrate from the first vacuum processing chamber to a transfer chamber. Moving, temperature measuring the substrate in the transfer chamber, moving the substrate to a second vacuum processing chamber,
The substrate is etched by the vacuum processing chamber of
30. The temperature of the substrate is measured in the transport chamber by moving the substrate to the transport chamber.
A film forming method using the vacuum processing apparatus according to any one of 1, 33. 39. The film forming method according to claim 38, wherein an infrared radiation thermometer is used to measure the temperature in the transfer chamber. 40. When measuring the temperature in the transfer chamber, a reflector for reflecting radiant heat from a base body made of a member which is a mirror surface with respect to the measurement wavelength of the infrared radiation thermometer faces the base body. 39. The film forming method according to claim 38, wherein the film forming method is provided as follows. 41. The film forming method according to claim 35 or 38, wherein a temperature change of the substrate during the transport time is calculated, and the temperature of the substrate at the start or end of the vacuum treatment is calculated.