JP2003098111A - Method for inspecting defect and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that it takes an enormous amount of time to analyze detected foreign objects when the number of detected objects by an inspecting apparatus is large, leading to a delay in taking countermeasures against failures of a manufacturing process while a total number of detected objects is outputted as the detected result of the foreign object defect-inspecting apparatus and the countermeasure against failures of the manufacturing process is taken by analyzing foreign objects/defects detected by the inspecting apparatus conventionally. SOLUTION: In the defect inspecting apparatus which inspects by an optical system, failure causes are related to sizes of foreign objects or defects in the result, and a data processing means points out the failure cause from statistics of the inspection result and displays information on the inspection result. A threshold where a semiconductor wafer or the like becomes defective is set for each region of the semiconductor wafer or the like, and a defect analysis is carried out by statistically evaluating foreign objects.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defect inspection method and apparatus for inspecting defects such as foreign matter defects and pattern defects, and relates to a thin film substrate, a semiconductor substrate, a photomask, etc. in the production of semiconductor chips and liquid crystal products. A defect inspection method capable of displaying the inspection result in a format that is easy for the user to analyze and inspecting the defect cause in the inspection of the foreign matter defect existing in the Regarding the device.

[0002]

2. Description of the Related Art Conventionally, a technique for detecting a defect on a semiconductor substrate or the like by an optical measuring means is widely known. For example, in the "semiconductor wafer inspection device" of Japanese Patent Laid-Open No. 62-89336, a laser is irradiated onto the semiconductor substrate to detect scattered light from the foreign substance generated when the foreign substance adheres to the semiconductor substrate. There is disclosed a technique that enables inspection of a foreign matter defect or a pattern defect by comparing the inspection result of the same type semiconductor substrate that was inspected immediately before.

In addition, Japanese Patent Laid-Open No. 5-273110, "Method and apparatus for measuring size information of particles or defects"
, The size of the particle or crystal defect is measured by irradiating a laser beam to the object to be inspected, receiving scattered light from the particle or crystal defect of the object to be subjected to image processing. A method is disclosed.

Also, 4-42 to 4-4 of the proceedings of ULSI technology seminar in SEMICON Kansai in 1997
7. “Yield Monitoring and Analysis in Semicon
“Ductor Manufacturing” discloses a yield analysis method based on foreign matter defects detected on a semiconductor wafer.

[0005]

Conventionally, a management method for monitoring foreign matter defects and pattern defects on a substrate has been used as one of the methods for controlling the manufacturing process of a product in a manufacturing line for semiconductor substrates, thin film substrates and the like. Has been. As one of such monitoring methods, there is used a method of inspecting with a defect inspection device for inspecting foreign matter defects or pattern defects on the substrate, and monitoring the transition of the number of detections from the defect inspection device. Therefore, a defect analysis was performed on a substrate having a large number of detections for foreign matter defects and pattern defects on the substrate.

However, in this prior art method,
The time required for failure analysis is "detection number x failure analysis time for one particle / defect", especially when the number of particles detected by the inspection system for particle defects is large, it takes a huge amount of time for failure analysis. Therefore, there is a problem that the production of the substrate is delayed.

The present invention has been made in order to solve the above-mentioned conventional technique, and its purpose is to carry out a foreign matter defect (hereinafter, simply referred to as a foreign matter) when inspecting a manufacturing process of a semiconductor wafer or a thin film substrate and conducting defect analysis. The defect inspection method and its equipment are capable of performing quick defect countermeasures by inspecting according to the size of the defect, the size of the pattern defect (hereinafter, simply referred to as defect), and the characteristics of the area of the object to be inspected. To provide.

[0008]

In order to achieve the above object, in the defect inspection apparatus according to the present invention, a defect inspection apparatus for measuring an object to be inspected by an optical method to detect foreign matters and defects is provided. Illuminating means for irradiating the object to be inspected with light, light detecting means for detecting reflected light or scattered light from the object to be inspected, and a signal detected by the light detecting means based on a foreign substance or a defect. Detecting means for detecting, dimensional measuring means for performing signal processing on the basis of the signal detected by the light detecting means to measure the size of the foreign matter or defect, data processing means for processing the inspection result, and inspection And a means for displaying the result information of the above, and the cause of the defect is pointed out from the statistical processing of the inspection result by the data processing means in association with the size of the foreign matter or defect and the cause of the defect. And to display the means for displaying the result information.

In order to achieve the above object, in the defect inspection apparatus according to the present invention, in the defect inspection apparatus for measuring foreign matter and defects by measuring the inspected object by an optical method, the inspected object is Illuminating means for irradiating light, light detecting means for detecting reflected light or scattered light from the object to be inspected, and detecting means for detecting a foreign substance or a defect based on a signal detected by the light detecting means. Based on the signal detected by the light detecting means, a dimension measuring means for performing signal processing to measure the size of a foreign substance or a defect, a data processing means for processing an inspection result, and inspection result information. A means for displaying is provided, and a frequency distribution display of the size of the foreign matter or defect obtained by the dimension measuring means is performed on the means for displaying the result information of the inspection.

In order to achieve the above object, in the defect inspection apparatus according to the present invention, in the defect inspection apparatus for measuring foreign matter or defects by measuring the inspected object by an optical method, the inspected object is Illuminating means for irradiating light, light detecting means for detecting reflected light or scattered light from the object to be inspected, and detecting means for detecting a foreign substance or a defect based on a signal detected by the light detecting means. Based on the signal detected by the light detecting means, a dimension measuring means for performing signal processing to measure the size of a foreign substance or a defect, a data processing means for processing an inspection result, and inspection result information. A means for displaying is provided, and the foreign matter or defect of a specific size is discriminated from other foreign matter or defects and displayed on the means for displaying the result information of the inspection.

In order to achieve the above object, in the defect inspection apparatus according to the present invention, in the defect inspection apparatus for measuring foreign matter or defects by measuring the inspected object by an optical method, the inspected object is Illuminating means for irradiating light, light detecting means for detecting reflected light or scattered light from the object to be inspected, and detecting means for detecting a foreign substance or a defect based on a signal detected by the light detecting means. Based on the signal detected by the light detecting means, a dimension measuring means for performing signal processing to measure the size of a foreign substance or a defect, a data processing means for processing an inspection result, and inspection result information. A means for displaying is provided, management information is provided for each area of the object to be inspected, and the management information and the size of the foreign matter or defect detected from the area are compared,
By evaluating the quality of each region of the object to be inspected and the defect, it is possible to analyze the defect for each region.

Further, in order to achieve the above object, in the defect inspection apparatus according to the present invention, in the defect inspection apparatus which measures an object to be inspected by an optical method and detects foreign matters and defects, the object to be inspected is Illuminating means for irradiating light, light detecting means for detecting reflected light or scattered light from the object to be inspected, and detecting means for detecting a foreign substance or a defect based on a signal detected by the light detecting means. Based on the signal detected by the light detecting means, a dimension measuring means for performing signal processing to measure the size of a foreign substance or a defect, a data processing means for processing an inspection result, and inspection result information. A means for displaying, the object to be inspected is managed for each area, and as a means for displaying the result information of the inspection, the foreign matter or the defect obtained by the dimension measuring means The frequency distribution display size, thereby to perform for each area.

In order to achieve the above object, in the defect inspection apparatus according to the present invention, in the defect inspection apparatus which measures an object to be inspected by an optical method and detects foreign matters and defects, the object to be inspected is Illuminating means for irradiating light, light detecting means for detecting reflected light or scattered light from the object to be inspected, and detecting means for detecting a foreign substance or a defect based on a signal detected by the light detecting means. Based on the signal detected by the light detecting means, a dimension measuring means for performing signal processing to measure the size of a foreign substance or a defect, a data processing means for processing an inspection result, and inspection result information. Means for displaying, and as means for displaying the result information of the inspection, the size of the foreign matter or defect obtained by the dimension measuring means and the quality of the inspection object by electrical inspection. Based on the information of the defective, and to be able to view the effect on the yield of foreign matters or defects.

Further, in order to achieve the above object, in the defect inspection method according to the present invention, in the defect inspection method of measuring an object to be inspected by an optical method to detect foreign matters and defects, the object to be inspected is To illuminate the
A procedure for detecting reflected light or scattered light from the object to be inspected, a procedure for detecting a foreign matter or a defect based on the detected signal, and a signal processing based on the detected signal, the foreign matter or The procedure for measuring the size of the defect, the data processing procedure for processing the inspection result, and the procedure for displaying the inspection result information are performed in this order, and the size of the foreign substance or defect and the cause of the defect are associated with each other, and In the data processing procedure, the cause of the defect is pointed out from the statistical processing of the inspection result, and the result information of the inspection is displayed.

Further, in order to achieve the above object, in the defect inspection method according to the present invention, in the defect inspection method of measuring an object to be inspected by an optical method to detect foreign matters and defects, the object to be inspected is A procedure of irradiating an object with light, a procedure of detecting reflected light or scattered light from the object to be inspected, based on a detected signal, a procedure of detecting a foreign substance or a defect, and a detected signal Signal processing to measure the size of foreign particles or defects,
The data processing procedure for processing the inspection result and the procedure for displaying the inspection result information are performed in this order, and when displaying the inspection result information, the foreign substance or defect obtained by the procedure for measuring the dimension The frequency distribution of the size of was displayed.

Furthermore, in order to achieve the above object, in the defect inspection method according to the present invention, in the defect inspection method of measuring an object to be inspected by an optical method to detect foreign matters and defects, the object to be inspected is A procedure of irradiating an object with light, a procedure of detecting reflected light or scattered light from the object to be inspected, based on a detected signal, a procedure of detecting a foreign substance or a defect, and a detected signal Signal processing to measure the size of foreign particles or defects,
A data processing procedure for processing the inspection result and a procedure for displaying the inspection result information are performed in this order, and when the inspection result information is displayed, a foreign matter or defect of a specific size is transferred to another foreign matter or a defect. It is displayed so that it is discriminated from defects.

Further, in order to achieve the above object, in the defect inspection method according to the present invention, in the defect inspection method of measuring an object to be inspected by an optical method to detect foreign matters and defects, the object to be inspected is A procedure of irradiating an object with light, a procedure of detecting reflected light or scattered light from the object to be inspected, based on a detected signal, a procedure of detecting a foreign substance or a defect, and a detected signal Signal processing to measure the size of foreign particles or defects,
The data processing procedure for processing the inspection result and the procedure for displaying the inspection result information are performed in this order, and management information is provided for each area of the inspection object, and the management information and the foreign matter detected from the area are provided. Alternatively, by comparing the sizes of the defects and evaluating the quality of each region of the object to be inspected, the defect analysis can be performed for each region.

Furthermore, in order to achieve the above object, in the defect inspection method according to the present invention, in the defect inspection method of measuring an object to be inspected by an optical method to detect foreign matters and defects, the object to be inspected is A procedure of irradiating an object with light, a procedure of detecting reflected light or scattered light from the object to be inspected, based on a detected signal, a procedure of detecting a foreign substance or a defect, and a detected signal Signal processing to measure the size of foreign particles or defects,
The data processing procedure for processing the inspection result and the procedure for displaying the inspection result information are performed in this order, and the inspection object is managed for each area, and when the inspection result information is displayed. The frequency distribution display of the sizes of foreign matters or defects obtained by the procedure of measuring the dimensions for each area is performed for each area.

Furthermore, in order to achieve the above-mentioned object, in the defect inspection method according to the present invention, in the defect inspection apparatus for measuring the object to be inspected by an optical method to detect foreign matters and defects, the object to be inspected is Illuminating means for irradiating an object with light, light detecting means for detecting reflected light or scattered light from the object to be inspected, and detection for detecting a foreign substance or defect based on a signal detected by the light detecting means Means, dimension measurement means for performing signal processing on the basis of the signal detected by the light detection means to measure the size of a foreign substance or defect, data processing means for processing the inspection result, and inspection result information And a means for displaying the inspection result information as means for displaying the result information of the inspection, the size of the foreign matter or defect obtained by the dimension measuring means, and the electrical inspection of the inspected object. Based on the information of good or bad, and to be able to view the effect on the yield of foreign matters or defects.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Each embodiment of the present invention will be described below.

[Configuration and Operation of Defect Inspection Apparatus According to the Present Invention] First, the configuration and operation of the defect inspection apparatus according to the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a diagram showing the structure of a defect inspection apparatus according to the present invention.

FIG. 2 is a block diagram when the defect inspection apparatus according to the present invention is operated as a system.

In the following, the embodiment will be described by exemplifying a case of inspecting a foreign matter defect on a semiconductor wafer, but the present invention can also be applied to an apparatus for inspecting a pattern defect other than a foreign matter. Further, not only the semiconductor wafer but also a thin film substrate, a photomask, a TFT, a PDP and the like can be applied.

A defect inspection apparatus for inspecting a foreign matter defect or a pattern defect according to the present invention includes an illumination optical system 101, a detection optical system 103, a photodetection section 104, and a signal processing circuit 10.
5, data display unit 106, stage unit 107, autofocus illumination unit 108, autofocus light receiving unit 109
It consists of

When the inspection is performed, the inspection object 102
Is placed on the stage 107, the illumination optical system 101 illuminates the inspection object 102, and the scattered light from the inspection object 102 is condensed by the detection optical system 103. Then, the light detection unit 104 detects scattered light from the inspection object 102. Light detection unit 104
The scattered light detected in 1 is subjected to photoelectric conversion and the like, and the signal processing circuit 105 performs signal processing to detect foreign matter,
Its size is measured.

Further, the object to be inspected 102 is moved in the horizontal direction by the stage unit 107, and further, the object to be inspected 102 is brought to the focus position of the detection optical system 103 by the autofocus illumination unit 108 and the autofocus light receiving unit 109. By moving in the vertical direction, the foreign matter can be detected and its size can be measured in the entire area of the inspection object 102. Then, the detection result is displayed on the data display unit 106.

Here, the illumination optical system 101 is, for example, A
A laser light source such as an r laser, a semiconductor laser, a YAG laser, or a UV laser, or a white light source such as an Xe lamp or an Hg lamp is used to irradiate the object 102 with light by using a beam expander, a collimator lens, a cylindrical lens, or the like. And is adjusted so that the focal position of the detection optical system 103 is irradiated with light. Here, as a method of selecting a light source, a YAG laser, an Ar laser, or a UV laser is suitable because it is better to use a light source with a short wavelength as an illumination light source when improving the detection sensitivity of a foreign substance. A semiconductor laser is suitable for a small and inexpensive device. Further, when it is desired to reduce the interference due to the light-transmissive thin film formed on the inspection object, a white light source is suitable as the illumination light source.

The shape of the irradiation light may be circular illumination or linear illumination. Further, the illumination light may or may not be parallel light, and if it is desired to increase the light amount per unit area on the inspection object, increase the output of the illumination light source or increase the illumination light to a high NA. You can illuminate with.

Next, the detection optical system 103 is the illumination optical system 1
The optical lens is configured to collect scattered light from the inspection object 102 among the light emitted by 01 on the photodetector 104. Further, the detection optical system 103 is
Optical processing for the scattered light, for example, change / adjustment of optical characteristics by a polarizing plate or a spatial filter can be performed.

Here, when a polarizing plate is used as the optical treatment, the polarizing plate is set in a direction in which P polarized light is transmitted when S polarized light is irradiated, and in a direction in which S polarized light is transmitted when P polarized light is irradiated. It is better to set a polarizing plate. When using a spatial filter, the use of parallel light as the illumination light improves the foreign matter detection performance.

The photo-detecting section 104 is used for receiving and photoelectrically converting scattered light collected by the detection optical system 103, and for example, a TV camera, a CCD linear sensor, a TDI sensor, or an anti-blooming TDI sensor. And Photomaru.

Here, as a method of selecting the photodetector section 104, it is preferable to use photomul when detecting a small amount of light. Further, a TV camera is preferable for obtaining a two-dimensional image at high speed, and when the detection optical system 103 is an image forming system, a TV camera, a CCD linear sensor, a TDI sensor, or an anti-blooming TDI sensor is preferable. When 103 is a condensing system, it may be a photomultiplier. Further, when the dynamic range of the light received by the photodetector 104 is large, that is, when the sensor saturates light, a sensor with an anti-blooming function is preferable.

Next, the signal processing circuit 105 is composed of a portion for detecting foreign matter and a portion for measuring the size of the foreign matter. When a foreign substance is detected by the signal processing circuit 105, for example, the input signal is binarized, and a signal having a binarization threshold value or more is determined to be a foreign substance and is output. The signal processing circuit 105 also measures the size of the foreign matter, and the processing will be described in detail later. Further, the stage unit 107 includes, for example, a mechanism for moving the inspection object 102 in horizontal and vertical directions and rotating the inspection object 102. In addition, the auto-focus illumination unit 108 includes, for example, a white light source such as an Hg lamp and an H light source.
Light emitted from a laser light source such as e-Ne is inspected 1
Focus on 02. Here, it is better to use a light source having a wavelength different from the wavelength of the light source used in the illumination optical system 101 as the wavelength of the light source used in the autofocus illumination unit 108.

Next, the autofocus light receiving section 109
Of the light emitted from the autofocus illumination unit 108, it is a portion that receives the light reflected from the inspection object 102, and for example, a position sensor that can detect the position of the light is used. Further, the information obtained by the autofocus light receiving unit 109 is sent to the stage unit 107 and used for controlling the stage. In addition, in the example shown in FIG.
Although an example of illuminating from one direction is shown, the configuration may be such that illuminating from two or more directions. Further, in the example of FIG. 1, each of the detection optical system 103 and the detection unit 104 is
That is, the detection is performed in one direction with respect to the inspection object 102, but it is also possible to have two or more of these and detect in two or more directions.

Next, an example of a method of setting the detection condition of a foreign substance or a defect when the size of the foreign substance is used in the defect inspection apparatus according to the present invention will be described. There are several conditions to be set, such as optical conditions and signal processing conditions,
Here, as an example, a method of setting the irradiation intensity of the illumination light source will be described.

In the defect inspection apparatus, when the reflected light from the circuit pattern printed on the object to be inspected has a proportional relationship between the amount of light incident on the photodetector and the irradiation intensity of the illumination light source, the irradiation intensity of the illumination light source is When the number is increased, the reflected light from the circuit pattern also increases, and the reflected light saturates the photoelectric conversion element of the photodetector. If the reflected light from the circuit pattern is saturated in the photodetector, the signal obtained from this circuit pattern will be the saturation value of the photodetector, and the signal value will be the same regardless of the presence or absence of foreign matter on the circuit pattern. I will end up. Therefore, the foreign matter on this circuit pattern cannot be detected. That is, when the irradiation intensity of the illumination light source is increased, the circuit pattern in which the foreign matter cannot be detected increases and the area in which the foreign matter can be detected decreases.

The degree of decrease in the area where foreign matter can be detected depends on the irradiation intensity of the illumination light source, the reflectance of the material used for manufacturing the circuit pattern, the complexity of the circuit pattern structure, and the optical processing. It depends on the method. When the area in which the foreign matter can be detected changes depending on the irradiation intensity of the illumination light source, the detection condition may be determined using the graph shown in FIG. 41, for example. First, FIG. 41 will be described. 41 is a graph in which the horizontal axis represents the minimum value of the size of the foreign matter to be detected, and the vertical axis represents the area in which the foreign matter can be detected. In this example, when the irradiation intensity of the illumination light source is increased, smaller foreign matter can be detected, but the area in which the foreign matter can be detected decreases.

In FIG. 41, a curved line 4101 indicates a region in which foreign matter having a size larger than that shown on the horizontal axis can be detected.
In this example, 0.1 μm on the horizontal axis corresponds to the condition for detecting a foreign substance of 0.1 μm or more. In this case, since the irradiation intensity of the illumination light source needs to be increased, the reflected light of many circuit patterns is light. The area where the foreign matter can be detected by saturating the detection portion is 15%. Further, when the condition for detecting a foreign matter of 1 μm or more is used, the foreign matter can be detected even if the irradiation intensity of the illumination light source is weak, so that the amount of light reflected from the circuit pattern is reduced and the circuit pattern that saturates the photodetection unit is detected. It is shown that foreign matter can be detected in 85% of the area of the object to be inspected.

The operator of the defect inspection apparatus of the present invention can determine the desired detection condition by designating the size of the foreign matter to be detected or by designating the detectable area from the graph shown in FIG. For example, the detectable area is 50%
, The defect inspection apparatus of the present invention is 0.65 μm.
The irradiation intensity that can detect the foreign matter is automatically set. The relationship between the size of the foreign matter to be detected and the irradiation intensity of the illumination light source may be measured in advance by the defect inspection device of the present invention.

Since the shape of the curve 4101 shown in FIG. 41 changes depending on the object to be inspected, it is better to measure it for each object to be inspected. As a measuring method, the reflected light from the inspected object may be actually measured and the saturated area may be calculated.If the saturated area can be predicted from the inspected object design information, the design information is used. It may be calculated by The former has the advantage of being able to perform measurement if there is an object to be inspected because it does not require design information, and the latter has the advantage of being able to set detection conditions in advance and shortening the condition setting time.

In this example, the method of setting the irradiation intensity condition of the illumination light source from the size of the foreign matter to be detected has been described. However, the threshold of signal processing may be changed depending on the size of the foreign matter to be detected. In this case, for example, in a defect inspection apparatus in which the irradiation intensity of the illumination light source is kept constant and it becomes difficult to detect foreign matter when the threshold value for foreign matter detection is increased, when only large foreign matter needs to be detected, If it is necessary to increase the threshold value and detect small foreign matters, on the contrary, the threshold value may be set small.

Next, the system in the semiconductor device manufacturing line will be described with reference to FIG. FIG. 44 shows a semiconductor device manufacturing process 4401 and an inspection process 4402.
The inspection apparatus group 4403 for inspecting foreign matters or defects, the database 4404, and the measurement apparatus group 4405 for managing the process state are included.

Here, the inspection device group 4403 is, for example, the defect inspection device of the present invention, and detects foreign matter or defects,
Classify foreign matter or defects. In addition, the measuring device group 440
5 is, for example, a device for judging good or bad by an electrical test, a device for analyzing components, a device for measuring the film thickness of a film applied to the device, a device for measuring a pattern width formed on the device, or a space between patterns. It is a device for measuring conductivity and a review device for foreign substances or defects. Further, in the database 4404, the inspection result of the inspection device group 4403, the measurement result of the measurement device group 4405, the information of the device manufacturing process, the past failure case, and the like are stored.

Next, the operation of the device manufacturing system shown in FIG. 44 will be described. First, a semiconductor device is manufactured through each process according to the device manufacturing process 4401. Inspection process 4 during the manufacturing process
If a defect is inspected at 402 and a defect has occurred, the inspection result is compared with the information in the database 4404 and the measurement result by the measuring device group 4405, and the defect countermeasure method is fed back to the device manufacturing process 4401.

Next, a system is constructed using the defect inspection apparatus according to the present invention, as shown in FIG. That is, this system is the foreign matter inspection apparatus 130 of the present invention.
1, a data server 1302, a review device 1303, an electrical test device 1304, an analysis device 1305, and a network 1306 connecting each device. Here, the review device 1303 is, for example, a length-measuring SEM, the electrical test device 1304 is a tester, and the analysis device 1305 is a device that analyzes a foreign matter component such as EDX. In addition, the data server 1302
Inspection data of the foreign substance inspection device 1301 and the review device 13
03 is a computer capable of collecting and accumulating the review result of 03, the test result of the electrical test device 1304, and the analysis result of the analysis device 1305. The network 1306 is
For example, it is a communication network using Ethernet (registered trademark).

Next, the operation of the system using the defect inspection apparatus will be described. After the foreign substance inspection device 1301 has performed the inspection, the foreign substances that require countermeasures are selected by the method described above. The information of the selected foreign matter is added to the inspection result of the foreign matter inspection apparatus 1301, for example, the serial number when detecting the detected foreign matter, the position information of the foreign matter, and the size information of the foreign matter, and the network 130 is added to the data server 1302.
Send via 6. Here, as a method of adding information on the selected foreign matter, for example, a flag indicating whether or not a countermeasure is necessary may be added to the inspection result. Then, in order to investigate the foreign matter detected by the foreign matter inspection apparatus 1301 in more detail, the inspection object is moved to the review apparatus 1303. This movement may be performed manually or mechanically. After moving the inspection object to the review device 1303,
The data server 1302 is accessed from the review device 1303, and the data server 1 is accessed via the network 1306.
The inspection result is received from 302. Then, the review is started using this inspection result. At this time, the foreign matter inspection device 1
By using the information added by 301 to preferentially review foreign substances that require countermeasures, it is possible to quickly analyze the foreign substances that cause defects. Also,
Similarly, also in the analysis device 1305, the foreign matter inspection device 13
The information added by 01 enables preferential analysis of foreign substances that require countermeasures, and allows quick analysis of the cause of defects.

These review data and analysis results are accumulated in the data server 1302, and the electric test equipment 1
By comparing with the test result in 304, it is possible to confirm whether or not the defect finally occurs. if,
If it does not finally become defective, the data server 130
2 transmits to the foreign matter inspection device 1301 data for changing the criterion for selecting a foreign matter requiring a countermeasure, and changes the criterion of the foreign matter inspection device 1301 for countermeasures,
It becomes possible to select a foreign substance that requires countermeasures with higher accuracy, and it is possible to promptly take countermeasures against defects in semiconductor manufacturing.

In the above description, data is transmitted and received via the network, but the data need not necessarily be transmitted via the network, and data of a removable storage medium or printed paper can be used. You may hand over.

Further, the foreign matter inspection device 130 according to the present invention.
Another usage of the combination of 1 and the review device 1303 will be described. FIG. 16 is a diagram showing a part of FIG. 13 extracted. In FIG. 16, reference numeral 1601 denotes an inspection device, for example, the defect inspection device of the present invention. Further, 1602 is a reviewing device for foreign matter / defects on the inspection object, for example,
It is a measuring SEM. Further, 1603 is the inspection device 1
A network for transmitting and receiving data between the 601 and the review device 1602, for example, a system connected by Ethernet. Next, the operation will be described. However, in the following description, a foreign substance will be described as an example.

First, the inspection device 1601 inspects foreign matter on the object to be inspected, and adds the inspection result, for example, the serial number when detecting the detected foreign matter, the position information of the foreign matter, and the size information of the foreign matter, and the network 1603 is added. Via review device 16
The inspection data is transmitted to 02. After moving the object to be inspected to the review device 1602, the review device 1602 carries out a review operation of foreign matter. At this time, according to the size information of the foreign matter measured by the inspection device 1601, the review device 1
By changing the magnification at the time of review in 602, efficient review can be performed. That is, the inspection device 1601
When the size information of the foreign matter obtained from the above indicates a small foreign matter, it is possible to quickly observe the details of the small foreign matter by performing the review at a high magnification during the review. Further, when the foreign matter size information indicates a large foreign matter, the review can be performed at a low magnification at the time of review, and even if the foreign matter is large, the foreign matter can be reviewed without protruding from the review screen, and the entire foreign matter can be reviewed. The image can be observed quickly. For example,
When the size of the foreign matter in the inspection data transmitted from the inspection device 1601 is 0.1 μm, the review magnification is set in the review device 1602 so that the field of view is 1 μm, and the review is performed. In the case of 10 μm, the review magnification of the review device 1602 is 100 μ
m is set so that the review is performed. As a result, it is possible to efficiently review from a small foreign substance to a large foreign substance, and it is possible to quickly analyze the detected foreign substance.

In this example, the size information of the foreign matter is output from the inspection device 1601 and the magnification of the review device is changed according to the size. However, as another method,
Information on the review magnification and the field of view of the review device 1602 may be added to the inspection data of the inspection device 1601. Further, in this example, as the review magnification of the review apparatus 1602, an example in which the review is performed at a magnification that provides a field of view of 10 times the size of the foreign matter has been described, but other magnifications may be used and the foreign matter in the inspection apparatus 1601 may be used. If the accuracy of the position information is known, the review may be performed at a magnification that takes into consideration the accuracy of the foreign matter size information and the accuracy of the position information.
Further, in this example, as the review apparatus, the case of the length measurement SEM has been described, but a review SEM or an optical microscope system may be used, and the present method can be applied to an apparatus or a function intended for review. .

Further, in this example, the example in which the review of the foreign matter is performed by the review device 1602 has been described, but the present method can be applied also when the review of the foreign matter is performed by the foreign substance and defect inspection apparatus of the present invention. is there.

[Measurement of Size of Foreign Material] Next, a process of measuring the size of a foreign material by the defect inspection apparatus of the present invention will be described.

FIG. 3 is a diagram showing image data when a foreign substance exists and a diagram showing a distribution of signal intensity when the foreign substance data is measured.

FIG. 4 is a diagram comparing two types of signal intensity distributions and an explanatory diagram for obtaining the maximum value of the signal intensity.

FIG. 3A shows an example of an image processed by the signal processing circuit 105 when a foreign substance is present, and the foreign substance data 201 is present in the center of the image. The foreign matter data 201 is output from the light detection unit 104 and is captured by the signal processing circuit 105 as data having a gray value. FIG. 3B is a three-dimensional representation of FIG. 3A. The x and y axes are coordinate axes for determining the position in the image, and the z axis plots the signal intensity at that position. However, they are connected by a line. In this FIG. 3 (b),
A waveform 202 shows the waveform data of the foreign matter data 201. This waveform 202 is a waveform that can be approximated to a Gaussian distribution due to the properties of the illumination optical system 101 and the detection optical system 103,
The width and height of this Gaussian distribution change depending on the size of the foreign matter on the inspection object 102. Furthermore, the width and height of the distribution also change depending on the illuminance of the laser illumination used in the illumination optical system 101. Therefore, if the shape of the distribution and the characteristic amount are measured in advance with respect to various standard particles by the device configuration of the present invention and the measurement result is compared with the detected waveform 202, the size information of the detected foreign matter is obtained. Obtainable.

Here, the waveform of the standard particles and the waveform of the foreign matter 20
As a method of comparing the two, the total (integrated value) of the signal intensity of the foreign matter data 201 portion, that is, the volume data of the waveform 202 is measured, and the volume data of the standard particles and the volume data of the foreign matter data 201 are compared. do it. However,
If there is a difference in the illuminance of the illumination optical system 101 when measuring these data, the volume data is normalized by dividing by the illuminance of the illumination optical system 101 used, or the ratio of the illuminance is determined by the foreign matter data 201. Alternatively, the volume data is corrected by multiplying the volume data of standard particles.

As another method of comparing the waveforms, the maximum value of the signal intensity of the waveform 202 or the width of the waveform 202 may be compared. In addition to the volume data, the number of pixels on the image of signals of standard particles or foreign matter may be used. This will be described with reference to FIG. 42 (a) is shown in FIG. 3 (a).
Similarly, it is an image of a foreign substance, and the foreign substance data 4201 is a signal of the foreign substance due to the reflected light from the foreign substance. In addition, FIG.
(B) is a diagram showing the gray value of the foreign matter data 4201, and the foreign matter signal section 4202 is a foreign matter signal. In the case of FIG. 42 as an example, the volume data is the sum of the gray values of the pixels, so the value is 527. Further, the number of pixels on the image is 14 pixels because it is the number of pixels in the foreign object signal portion 4202, and the width of the signal is 5 pixels in the x direction and 5 in the y direction.
It is a pixel.

A method for obtaining the maximum value of the signal strength will be described with reference to FIG. FIG. 4 shows an example of the waveform data of the foreign substance data, similar to the waveform 202, and FIG.
Is an example in which the signal waveform of the foreign substance data obtained by the photodetector 104 is a mountain-shaped waveform having a peak, which indicates that the signal has not reached the saturation region of the photodetector 104. ing. Further, FIG. 4B is an example in which the signal waveform of the foreign matter data has a waveform like a plateau at the top, which means that the signal has reached the saturation region of the photodetector 104 and is equal to or higher than the saturation region. Indicates that there is no data.

When drawing a signal waveform as shown in FIG. 4A, the maximum value of the signal strength is the maximum value obtained by comparing the signal strength of each pixel of the waveform, that is, the peak point signal strength 30.
Let 1 be the maximum value of the signal strength. When the signal waveform as shown in FIG. 4B is drawn, the following calculation is performed to find the maximum value of the signal strength.

First, in the saturated region 302, the maximum length of the saturated region is obtained in the x and y directions. Figure 4
Shown in (c) is the maximum length portion of FIG.
It is a cross section of (b). In FIG. 4C, the horizontal axis is the coordinate axis showing the pixel position of the maximum length portion, and the vertical axis is the coordinate axis showing the signal intensity. In addition, the signal intensity 303 indicates the saturation level of the light detection unit 104. For this cross section, three or more unsaturated signals 304 are selected. Here, let's assume that three points are selected. As the points to be selected, three non-saturated signals of this cross-section are selected from the one having the highest signal intensity. If the respective coordinates are x1, x2, x3 and the signal intensities are z1, z2, z3 for the selected three data points, z1 = k / σ × exp using unknown values k, σ, u (-(X1-u) ^ 2 / (2 * [sigma]
^ 2)) z2 = k / σ × exp (-(x2-u) ^ 2 / (2 × σ
^ 2)) z3 = k / σ × exp (-(x3-u) ^ 2 / (2 × σ
^ 2)) Gaussian distribution formula is obtained. The unknowns k, σ, and u can be obtained by simulating the above three equations.

Then, by using the obtained values of k and σ, the maximum value of the signal intensity in FIG. 3B can be calculated as k / σ.

Although an example in which the unknown number u is used for the calculation is shown here, the unknown number u may not necessarily be used. In that case, two points of the signal 304 are selected. As the points to be selected, two unsaturated signals of the cross section are selected from the one having the highest signal intensity. With respect to the data of the two points, assuming that the respective coordinates are x1 and x2 and the respective signal intensities are z1 and z2, z1 = k / σ × exp (− (x1) ^ 2 using unknowns k and σ. / (2 × σ ^
2)) z2 = k / σ × exp (− (x2) ^ 2 / (2 × σ ^
2)) Gaussian distribution formula is obtained. The unknowns k and σ are 2
Since the values can be obtained by making simultaneous equations, the maximum value of the signal strength in FIG. 3B can be calculated as k / σ 2 by using the values of k and σ.

The size of the foreign matter can be measured by comparing the maximum value of the signal intensity obtained by the above calculation with the value of the standard particle and the detected value of the foreign matter.

Next, another embodiment for calculating the maximum value of the signal strength will be described with reference to FIG.

Similar to FIG. 4B, FIG. 17 shows a saturated signal distribution in which the signal waveform of the foreign matter data has a plateau-like waveform at the top and the shape of the saturated signal portion. It is the figure shown and explanatory drawing for calculating | requiring the maximum value of signal strength.

FIG. 17A shows the relationship between the signal waveform 1701 and the apex 1702. Since the signal waveform 1701 reaches the saturation region of the photodetector 104, there is data above the saturation region. The top is 1702
Is.

FIG. 17B shows a sectional waveform of the signal waveform 1701, where the vertical axis represents the signal intensity and the horizontal axis represents the pixel position of the signal. In the figure, the saturation level 1703 indicates the saturation level of the photodetector 104, and the signal width 1704 indicates the width of the top 1702. Further, the signal strength 1705 is the maximum value of the signal strength obtained when a detector that does not saturate is used as the detector used in the light detection unit 104.

Next, a method of calculating the maximum value 1705 of the signal strength from the saturated signal waveform 1701 will be described. When the saturation level 1703 is SL, the signal width 1704 is SW, and the signal strength 1705 is PL, and approximated to a Gaussian distribution, SL = k / σ × exp (− (− SW / 2) ^ 2 / (2 ×
σ ^ 2)) PL = k / σ is obtained. Here, k is a coefficient, and σ is a value calculated from the configuration of the optical system in the foreign matter and defect inspection apparatus of the present invention.

Therefore, from the above formula 2, PL is PL = SL / exp (-(-SW / 2) ^ 2 / (2 * σ
^ 2)) is calculated as Here, since SL is the output of the photodetector 104 at the time of saturation, for example, AD of the photodetector 104 is used.
When the converter has 8 bits, there are 255 gradations. Further, σ is given as a value of 0 to 1 depending on the configuration of the optical system. Next, a method of calculating SW will be described.

FIG. 17C shows the shape of the top 1702. That is, it is a region where the photodetector 104 is saturated. The figure shows a saturation region 1706 and a signal width 17
It is composed of 04. Here, since the signal waveform 1701 is considered to have a Gaussian distribution, the saturated region 1706 can be assumed to be a circle. Therefore, the signal width 1704 is set to SW, the saturation region 1
When 706 is SA, SW = 2 × √ (SA / π) can be calculated. Note that √ (A) means that the square root of A is calculated, and π is the pi. In addition, the saturated region 1706 may be the saturated region in which the number of pixels saturated by the light detection unit 104 is set. Here, the saturated pixel may be the maximum value of the output from the AD converter of the photodetector 104, and may be set in consideration of the electrical noise of the photodetector 104. For example, if the AD converter is 8
In the case of bits, the maximum output value is 255 gradations,
When there are 10 gradations of electrical noise, it may be considered that 245 gradations or more are saturated.

When the signal waveform 1701 is not saturated, the same calculation may be performed by using the maximum value of the signal waveform 1701 as the saturation level 1703.

Since the maximum value of the signal intensity can be calculated by the above calculation, the size of the foreign matter can be measured by comparing the value calculated by the standard particle with the value detected by the detected foreign matter. You can

In the above description, the maximum value of the signal strength is taken as an example, but instead of the maximum value of the signal strength,
You may use the integrated value of the signal strength of a foreign material. In this case, as a method of calculating the integral value of the signal intensity of the foreign matter, a value obtained by adding the grayscale value of each pixel of the detected foreign matter signal may be used. The advantage of using the integrated value is that the sampling error of the signal can be reduced. Here, a signal strength correction method using the integrated value of the signal strength will be described.
FIG. 45 is a three-dimensional representation of the Gaussian distribution. FIG. 45 shows a case where the signal is saturated at Y = Y0,
The method described below is a method of calculating the signal strength of the entire Gaussian distribution when the signal strength of the portion below Y = Y0 in FIG. 45, that is, the portion of V3 is obtained.
First, the volume of the entire Gaussian distribution in FIG. 45 is V1, Y = Y0
The volume of the upper part is V2, and the volume of the part below Y = Y0 is V3. Further, it is assumed that the cross-sectional shape on the X-axis of the Gaussian distribution in FIG. 45 is Y = exp (−X2 / 2 / σ2). At this time, V1 is expressed as V1 = 2 × π × σ2 by integrating around the Y axis. Further, V2 is V2 = 2 × π × σ2 (Y0 × Log (Y0) + 1-Y
It is represented by 0). In addition, "Log" in the above equation indicates that the natural logarithm is calculated. Here, the volume ratio V1
When / V3 is rewritten as CC, CC can be calculated by CC = V1 / (V1-V2). Therefore, from the above equation, CC = 1 / (Y0 × (1-Log (Y0))) is calculated. . Here, since Y0 = exp (-SW2 / 2 / σ2), CC = 1 / exp (-SW2 / 2 / σ2) / (1 + SW
It can be expressed as 2/2 / σ2). Therefore, the obtained signal strength is V3
, The overall signal strength V1 is: V1 = V3 × 1 / exp (−SW2 / 2 / σ2) / (1
+ SW2 / 2 / σ2) can be calculated and the signal strength can be corrected.

In the present description, an 8-bit AD converter has been described, but A having a bit number of 10 bits or more is used.
A D converter may be used. The advantage of having a large number of bits is that it is possible to finely grasp the change in the intensity of light obtained by the photodetector, and therefore it is possible to accurately calculate the size of a foreign substance or defect. Also,
In this example, the example in which the signal width 1704 is calculated as the diameter of the circle has been described, but the maximum width or the minimum width of the saturated region may be used instead of the diameter.

In the present embodiment, the example in which the illumination optical system 101 uses the laser light in the description of the above-mentioned device configuration has been described, but white light may be used instead of the laser light. In the case where the inspection object is a circuit pattern having repeatability, the size measurement process may be performed after taking the difference between the image in which the foreign matter does not exist and the image in which the foreign matter exists on the repeated pattern. . In addition, regardless of the presence or absence of repeatability, when scattered light data or reflectance data from the circuit pattern or film is obtained in advance for a foreign substance on the circuit pattern or film, for example, an oxide film or a metal film, The size data of the foreign matter may be corrected using the data. Furthermore, in order to measure the size of the foreign matter, the case where the size of the foreign matter is compared with the size of the standard particle has been described in this example, but the foreign matter having a known size may be compared with the standard particle.

Next, an example of a method of calculating the size of a foreign substance from the maximum value of the signal intensity when using the data of a foreign substance of a known size will be described with reference to FIG. FIG. 15 is a graph in which the maximum value of the signal intensity of the foreign matter obtained by the foreign matter and defect inspection apparatus of the present invention is set on the horizontal axis and the size of the foreign matter is set on the vertical axis. Here, the maximum value of the signal strength of the foreign matter is the value calculated by the above method, and the size of the foreign matter is measured by the review device such as a length measuring SEM to measure the lateral size and the vertical size. However, it is the value of the square root of the value obtained by multiplying the horizontal size and the vertical size. In FIG. 15, a plot point 1501 shows data for one foreign substance, and FIG. 15 shows a state in which data for a plurality of foreign substances is displayed. The approximate curve 1502 is an approximate curve calculated by the least square method based on the data of the plot points 1501. At this time, when the horizontal axis of the graph is x and the vertical axis is y, the approximate curve formula can be expressed as y = a × x + b. Here, a and b are values obtained by the least square method.

The method of calculating the size of the foreign matter from the maximum value of the signal strength is to obtain a relational expression between the maximum value of the signal strength and the size of the foreign matter, and use the relational expression to determine the foreign matter size from the maximum value of the signal strength. It suffices to calculate the size.

Next, the operation will be described. First, the approximate curve formula 1502 is calculated in advance by the above method. Next, the object to be inspected is inspected by the foreign matter and defect inspection apparatus of the present invention.
Then, at the time of the inspection, the maximum value of the signal intensity of the foreign matter described above is calculated. At this time, using the above-mentioned approximate curve equation, y calculated by substituting the maximum value of the signal intensity for x of the approximate curve equation may be used as the size of the foreign matter.

An example of the result calculated by the above method is shown in FIG.
0 and shown in FIG. FIG. 30 is a diagram in which the abscissa represents the size of the foreign matter calculated from the signal output of the defect inspection apparatus of the present invention, and the ordinate represents the size of the foreign matter measured by the length-measuring SEM, and the plot point 3101 is 1 Corresponds to the information of one foreign substance.
A straight line 3102 is an approximate straight line when each point of the plot points 3101 is approximated by least squares, and a numerical value 3103 indicates a correlation value of the plot points 3101.

Further, FIG. 30 (a) shows the measurement result of the size of the foreign matter detected on the wafer with a single-layer pattern, and FIG. 30 (b) shows the measurement result of the foreign matter detected on the wafer with a multi-layer pattern. It is the example which showed the measurement result of size.

In FIG. 31, as in FIG. 30, the horizontal axis shows the size of the foreign matter calculated from the signal output of the defect inspection apparatus of the present invention, and the vertical axis shows the size of the foreign matter measured by the length measuring SEM. In addition, it is an example in which an SEM photograph of the used foreign matter is also shown.

In this example, the square roots of the vertical size and the horizontal size were calculated.
The larger value of the size of the foreign matter in the vertical direction and the size of the horizontal direction may be set as the size of the foreign material, or the average value of the size in the vertical direction and the size in the horizontal direction may be set as the size of the foreign material. Further, the major axis of the foreign matter may be used, or the minor axis may be used. Further, the approximation curve may be approximated to a first-order curve, that is, a straight line, a higher-order curve, a logarithmic function curve, an exponential function curve, or a combination of a plurality of curves.

When the approximation curve is changed for each shape of the foreign matter, the size of the foreign matter calculated as described above and the measurement SE
If the correlation with the size of the foreign matter measured by M improves,
The approximate curve may be changed according to the shape of the foreign matter. Here, the difference in the shape of the foreign matter means that when the ratio of the size measured from above the foreign matter and the size measured from the side is different, for example, the difference between a spherical foreign matter and a flat plate-like foreign matter, or a foreign matter This is the difference from scratches.

Here, a method of distinguishing between a foreign matter and a scratch will be described with reference to FIG. FIG. 18 is a diagram showing a configuration for discriminating between a foreign matter and a flaw and a diagram showing a discrimination method. FIG. 18A shows a substrate 1801, a foreign substance 1802, an incident illumination light 1803, an oblique illumination light 1804, and a photodetector 18.
05, a storage circuit 1806, and a comparison circuit 1807. Here, the epi-illumination light 1803 is the light that is emitted to the substrate 1801 at an angle close to the direction perpendicular to the surface of the substrate 1801, and the oblique illumination light 1804 is emitted to the substrate 1801 at an angle that is close to the horizontal direction of the substrate 1801. Light, and the light source is, for example, an Ar laser or a YAG laser. The photodetector 1805 is a TV camera, a CCD linear sensor, a TDI sensor, or a photo sensor.

Next, the operation will be described. First, a foreign object or a flaw is irradiated with epi-illumination light 1803, scattered light from the foreign object or the flaw is detected by a photodetector 1805, and the amount of scattered light is stored in a storage circuit 1806. Next, epi-illumination light 180
The irradiation of No. 3 is stopped, the oblique illumination light 1804 is irradiated, the scattered light from the foreign matter or the scratch is detected by the photodetector 1805, and the scattered light amount is stored in the storage circuit 1806. Next, the light intensity of the storage circuit 1806 is compared by the comparison circuit 1807. The comparison circuit 1807 calculates the ratio of the scattered light amount when the epi-illumination light 1803 is irradiated and the scattered light amount when the oblique illumination light 1804 is irradiated, compares it with a threshold value determined in advance, and determines whether there is a foreign substance. Determine if it is a scratch. Here, as shown in FIG. 18B, the determination method may be performed by utilizing the fact that the ratio of the scattered light amount is small in the case of a foreign substance and the ratio of the scattered light amount is large in the case of a flaw. Next, an example of a method of setting a threshold value for determining whether it is a foreign matter or a flaw will be described. FIG. 46A is a graph in which the abscissa plots the scattered light amount by the incident illumination light and the ordinate plots the scattered light amount by the oblique illumination light. In this example, the review device determines in advance whether there is a foreign matter or a flaw, and the foreign matter is indicated by ◯ and the flaw is indicated by ▲.
Next, based on the graph of FIG. 46 (a), a discrimination line 4601 for separating foreign matter and scratches is added as shown in FIG. 46 (b).
Therefore, the discrimination line 4601 becomes a threshold value for determining whether a foreign matter or a flaw. The discrimination line 4601 may be arbitrarily set by the operator or may be automatically calculated. In the case of automatic calculation, there is an advantage that the same threshold value can be set by any operator.

Next, an example of a method for automatically calculating the judgment threshold value will be described with reference to FIG. 46 (c). As a procedure, first, an approximate straight line 4602 is calculated from the foreign substance data. Let this be Y = a × X + b. However, X is the horizontal axis of the graph, Y is the vertical axis of the graph, and a and b are numerical values obtained by the method of least squares. Next, an approximate straight line 4603 is calculated from the scratch data. Similar to the foreign substance data, the approximate straight line 4603 is set to Y = c × X + d. Note that c and d are numerical values obtained by the least squares method. At this time, the determination threshold value may be calculated as the intermediate straight line 4604 of the two approximate straight lines by the formula Y = ((a + c) / 2) × X + ((b + d) / 2).

In this example, a linear threshold value is used as the determination threshold value, but a curved line or a line formed by combining a plurality of curved lines may be used. Further, when there are three or more types to be determined, for example, when it is desired to determine a foreign substance, a scratch, and a pattern defect, a plurality of determination thresholds may be set. Further, in the present example, the case where the determination is made by two characteristic amounts, that is, the scattered light amount of the oblique illumination light and the scattered light amount of the epi-illumination light is described, but a characteristic amount other than the scattered light amount may be used, and three or more may be used. When the feature amount of is obtained, the determination may be made using a plurality of graphs as shown in FIG. In addition, as shown in FIG.
By displaying 01 together, the performance of the applied judgment threshold value may be shown.

In this example, an example in which the result determined by the review device in advance is used has been described. However, if it can be calculated in advance from past cases, it may be determined from past cases.

Next, a method of calculating the size of a foreign substance when it has a plurality of approximate curves will be described with reference to FIG. FIG. 19 includes a storage unit 1901 for the maximum value of the detection signal, a foreign matter / scratch discrimination unit 1902, a conversion curve selection unit 1903, and a foreign matter size calculation unit 1904.

Next, the operation will be described. First, in the defect inspection apparatus of the present invention, a conversion formula for calculating the size of the foreign matter from the maximum value of the signal intensity by the above-described method is created for the foreign matter and the scratch, and the conversion curve selection unit 1903 is created. Stored in. Next, the wafer is inspected by the inspection device. At this time, the maximum value of the signal intensity of the detected object is stored in the storage unit 1901. Next, the discriminating unit 1902 discriminates whether the detected object is a foreign matter or a flaw by the method described above. Based on this determination, a conversion curve is selected from the conversion curve selection unit 1903, and the selected conversion curve and the maximum value of the signal intensity stored in the storage unit 1901 are used as the foreign matter size calculation unit 190.
4, and the size of the foreign matter may be calculated. Details of the method of creating the conversion curve will be described with reference to FIG. First, the scattered light amount data of the detected substance detected by the defect inspection apparatus of the present invention is stored. Next, the detected object thus detected is reviewed by a reviewing device to determine whether it is a foreign matter or a defect, and further measure the size of the detected object. next,
Create a graph in which the scattered light intensity and the size of the detected substance are plotted for each foreign substance and defect. An example of the graph at this time is shown in FIG.
8 (a) (b). FIG. 48 (a) is a graph in which only the data of the foreign matter as the detected substance is plotted, and the horizontal axis is the amount of scattered light from the foreign matter, and the vertical axis is the size of the foreign matter measured by the review device. Further, the approximation curve 480
Reference numeral 1 is an approximate curve calculated from the data plotted in FIG. 48 (a), which is, for example, a straight line calculated by the method of least squares. Similarly, FIG. 48 (b) is a graph in which only the data of defects as detected substances are plotted. Further, the approximation curve 480
Reference numeral 2 is an approximate curve calculated from the defect data as in FIG.

These approximate curves 4 calculated by the above method
801 and the approximate curve 4802 are set as conversion curves, and in the subsequent inspection, the size can be calculated with high accuracy by calculating the size with the set conversion curve.

Although the present embodiment has been described with reference to the example in which the conversion curves are set according to the shapes of the foreign matter and the defect, it is also possible to detect the foreign matter by the detection position of the foreign matter with respect to the inspection object, for example, whether the foreign matter is on the circuit pattern. , Depending on whether there is a foreign matter in the part without pattern,
The approximate curve may be changed. In addition, the surface condition of the inspection object,
For example, the approximation curve may be changed depending on whether the surface is an aluminum film or a tungsten film.

[Calibration Method of Measured Foreign Particle Size] Next, a method of calibrating the foreign particle size measured by the defect inspection apparatus of the present invention will be described. This calibration is used in the foreign matter and defect inspection apparatus of the present invention when the illumination light amount changes due to deterioration of the illumination optical system 101 or the like.

An example of the calibration method will be described. First, a mirror-finished wafer having standard particles of known size attached thereto is prepared as a calibration wafer. It is desirable to prepare two or more types of standard particles. For example, it is a mirror-finished wafer to which 0.2 μm standard particles and 0.6 μm standard particles are attached. Next, these wafers are inspected by the foreign matter and defect inspection apparatus of the present invention, and the size of the detected foreign matter is displayed. At this time, if there is no problem with the inspection device, 0.2 μm and 0.6
A peak of the histogram occurs in the μm portion. For example, FIG. 26 is a graph in which the vertical axis indicates the number of detected foreign matters and the horizontal axis indicates the size of detected foreign matters. As shown in FIG. 26, the detected numbers are 0.2 μm and 0.6 μm. It is in a state of increasing. In contrast to the state of FIG. 26, FIG. 27 shows an example in which the laser light source used in the illumination optical system 101 is deteriorated and the illumination light amount is reduced to 1/2,
The number of detections increases in the areas of 0.1 μm and 0.3 μm. In other words, this is an example in which the amount of illumination light is reduced and the amount of scattered light is also reduced, so that the size of the foreign matter is measured smaller than the correct value.

Next, a method of obtaining a calibration coefficient for calibrating the inspection device will be described. First, the size of the standard particles inspected above is SS, and the size of the foreign matter measured by the inspection apparatus of the present invention is IS. At this time, since the amount of decrease in the illumination light amount is obtained by the ratio of SS and IS, the calibration coefficient is set to VR.
Then, since it can be calculated by VR = SS / IS, the calibration method may be to multiply the illumination light amount by VR or multiply the conversion formula when calculating the size of the foreign matter from the scattered light amount by VR. That is, in the above example, when the standard particle size SS is 0.2 μm and the foreign particle size IS measured by the inspection device is 0.1 μm, the calibration coefficient VR
Since VR = 2, the amount of illumination light can be doubled.

Here, an example in which a wafer to which standard particles of known size are adhered is used as the calibration wafer has been described, but the size of the foreign matter / defect may be known as the calibration wafer. Since it is sufficient, a wafer in which a defect having a known size is intentionally created may be used.

Next, another calibration method will be described with reference to FIG. This is a method of using a value measured by a review device as the size of the foreign matter. First, the foreign matter inspection device 1
The wafer is inspected at 301, and the inspection result, that is, the serial number at the time of detecting the detected foreign substance, the foreign substance position information, and the foreign substance size information is added and transmitted to the data server 1302 via the network 1306. After the wafer is moved to the review device 1303, the review operation is performed by the review device 1303, and the size information of the foreign matter measured there is added to the inspection result. Here, for example, when a length measurement SEM is used as the review device 1303, the size information of the foreign matter is obtained by measuring the size of the foreign matter in the horizontal direction and the size of the foreign matter in the horizontal direction with the length measurement SEM. The square root of the value obtained by multiplying the size in the vertical direction may be used as the size information of the foreign matter. Next, the information added to the inspection result is transmitted to the data server 1302, the added information is received by the foreign substance inspection device 1303, and the foreign substance size information output by the foreign substance inspection device 1303 is calculated based on the size information. Calibrate.

The calibration method will be described with reference to FIG. FIG. 28 is a graph in which the size information of each foreign substance measured by the foreign substance inspection device 1301 is set on the horizontal axis, and the size information measured by the review device 1303 is set on the vertical axis. FIG. 28
In FIG. 28, the plot point 2901 is the size information of the same foreign matter, and FIG. 28 shows the state in which the information of a plurality of foreign matter is plotted. Here, when the size of the foreign matter is measured correctly, the plot point 2901 is a straight line 2902.
It is plotted in the vicinity. As a calibration method, first, an approximate straight line is obtained from the data at the plot point 2901 by the least square method or the like. This approximate straight line is a straight line 2903, which is represented by y = a × x + b 2 here. However, x is the size of the foreign substance measured by the inspection device 1301 on the horizontal axis, and y is the review device 13 on the vertical axis.
The size of the foreign matter measured in No. 03. Also, a and b
Is a value calculated by the least squares method. Next, the defect inspection apparatus of the present invention inspects, measures the size of the foreign matter, and substitutes the measured size for x in the above equation, so that the obtained y is the same as the calibrated foreign matter size. Good.

Although the method of calibration is approximated to a straight line here, this is a high-order curve or a logarithmic function,
Alternatively, an exponential function may be used, or an equation combining a plurality of curves may be used. Further, the number of wafers used for calibrating the size of foreign matter is not limited to one, and a plurality of wafers may be used.

In the above description, the foreign matter inspection is performed using scattered light. One of the merits of this method is that foreign substances can be detected efficiently. Moreover, if the size of the foreign matter is determined by the method described above,
There is an advantage that finding a foreign substance and measuring its size can be performed by the same light source using scattered light without requiring a special light source for measuring the size.

[Analysis of Cause of Defects and Result Display] Next, a procedure for analyzing the cause of defects and a procedure for displaying the result to the user when the size of a foreign substance is measured by the defect inspection apparatus of the present invention will be described. .

FIG. 5 is a diagram showing that the relationship between the size of foreign matter and the number of generated foreign matter changes depending on the cause of the defect.

FIG. 6 is a line graph showing the number of detected foreign substances and the size of the foreign substances.

FIG. 7 is a diagram showing the number of detected foreign matters and the size of the foreign matters in a histogram.

FIG. 8 is a schematic view explicitly showing foreign matter of a specific size on the wafer.

FIG. 9 is a graph showing the change in the number of detected particles for each size of a particular foreign matter in time series.

FIG. 10 is a diagram of a screen for displaying the cause of a defect in which a foreign substance has occurred to the user.

FIG. 20 is a diagram showing a histogram of the number of detected foreign matters and the sizes of the foreign matters of a plurality of wafers.

FIG. 21 is a diagram showing a detected object on a wafer divided into foreign matters and scratches and shown in a histogram according to size.

One of the important ideas of the present invention is to use the size information of the foreign matter for analyzing the cause of the defect. Hereinafter, the effectiveness of using the size information of the foreign matter for the analysis of the cause of the defect will be described.

Here, it is assumed that foreign matter is detected from a wafer that has been subjected to a semiconductor manufacturing apparatus, for example, an etching apparatus, and the relationship between the size of the foreign matter and the number of generated foreign matter is as shown in FIG. A region 401 in FIG. 5A shows a distribution of foreign matter that is constantly generated during the process of the etching apparatus. In this case, the size of the foreign matter is concentrated in the portions a to b, and one gentle mountain is formed according to the size of the foreign matter.

On the other hand, FIG. 5 (b) shows an example of the foreign matter generation distribution when the apparatus is abnormal. In this case, in addition to the foreign matter in the steady state shown in the area 401, the area Large foreign matter as shown in 402 (portion of size c or more)
Is occurring frequently. It is considered that the cause of this is that the deposits deposited on the inner wall surface of the etching device during the etching process came off from the wall surface. Further, FIG. 5C also shows an example of the distribution of foreign matter generated at the time of abnormality. In this case, in addition to the foreign matter in the steady state, the size of the foreign matter is concentrated in the portions d to e. The cause of this is
It is possible that the specific pattern peeled off during the etching process.

As described above, in the manufacturing apparatus for semiconductors and the like, there is a relation between the size of the foreign matter generated and the cause of the foreign matter generation, and by managing the foreign matter generation situation of a specific size, the foreign matter generation in the manufacturing apparatus is controlled. The cause of occurrence can be quickly known. That is, the cause of the defect can be determined by examining the relationship between the size of the foreign matter and the number of generated foreign matters.

As a matter of course, the values of a to e, etc. are values that vary depending on the manufacturing apparatus, manufacturing process, etc. Further, foreign particles generated due to other causes have different size distributions. In some cases, it is better to use data that matches the size distribution of foreign matter for each cause of occurrence. Further, in this example, the cause of the generation of foreign matter is specified in two ranges, but it may be divided into two or more areas.

Next, the function of specifically analyzing the cause of the defect will be described.

First, the display of the size and detected number of foreign matter on the data display unit 106 will be described. Data display section 10
6, a graph of the size distribution of the foreign matter as described above, that is, a graph showing the relationship between the size of the foreign matter and the detected number of the foreign matter is displayed. FIG. 6 is a graph in which the horizontal axis represents the size of foreign matter and the vertical axis represents the number of detected foreign matter.
A point 501 indicates the number of detections by size, and in the example of this graph, data in units of 0.1 μm is shown.
A graph 502 is a line connecting the points 501 with a straight line. By displaying the graph as in this example, it is possible to quickly see how the distribution of the foreign matter detected from the inspection object 102 is.

Here, the minimum value on the horizontal axis may be set to, for example, the minimum detection size of the foreign substance inspection device or the size of the foreign substance to be managed on the semiconductor manufacturing line. Further, the scale may be displayed in logarithm as in this graph, may be linear, and the unit of the scale may be variable. Further, the display range of each axis may be fixed or variable. For example, by displaying only a specific size, only the foreign matter having a specific cause may be displayed. Further, the contents arranged on the vertical axis and the horizontal axis may be replaced with each other, and the density of foreign matter may be used instead of the number of detected foreign matter. Further, although the graph is displayed in this example, the average value of the graph or the standard deviation value or the variance value of the graph may be displayed in addition to the graph. Further, in this example, the foreign matter data for one wafer is displayed as one graph, but it does not necessarily have to be for one wafer, and the average value, standard deviation value, and variance of the foreign matter data for a plurality of wafers may be displayed. The value may be displayed, or the foreign matter data of a plurality of wafers may be displayed side by side.

Further, the graph may be displayed by a histogram as shown in FIG. 7 or 32. Similar to FIG. 6, the graphs of these figures are graphs in which the horizontal axis represents the size of foreign matter and the vertical axis represents the number of detected foreign matter. In this graph, the horizontal axis is displayed by dividing the size of the foreign matter into certain sections, and FIG. 7 shows a case where the data section is in units of 0.2 μm. In addition, in FIG. 32, the data section is set in units of 0.1 μm, and the data of foreign matter of 5 μm or more is counted in the portion of the bar graph 3301.
An example is shown in which the display color is changed between the histogram of foreign matter of less than 1.1 μm and the histogram of foreign matter of 1.1 μm or more. Furthermore, when a bar graph is selected, a function of displaying the position information of the detected foreign matter in the selected portion may be added, and a review image of the detected foreign matter in the selected portion may be displayed.

Further, FIG. 34 shows another example of the graph display. FIG. 34 shows an example in which the horizontal axis represents the size of foreign matter and the vertical axis represents the cumulative number of foreign matter. Here, the cumulative number indicates how many foreign matter having a size equal to or larger than a certain foreign matter is detected.

Further, FIG. 35 shows another example of the graph display. FIG. 35 shows an example in which the horizontal axis represents the size of the foreign matter and the vertical axis represents the number of detected foreign matters, and the curve 3601 of the detected foreign matter number and the expression 3602 of the curve 3601 of the detected foreign matter are written together. The expression 3601 represents the size of the foreign matter as x and the detected number of foreign matter as y, and is an approximate expression obtained from the number of detected foreign matter in the size of each foreign matter. A curve 3601 is an example in which the graph of Expression 3602 is displayed.

Further, FIG. 36 shows another example of the graph display. 36. In FIG. 36, the horizontal axis represents the size of foreign matter, and the vertical axis represents the foreign matter detection number ratio.
01 and the size of the foreign matter having the largest detection ratio value 3502
This is an example in which Here, the detected number ratio is the ratio of the number of foreign substances of each size to the total number of foreign substances detected by the inspection.

Further, FIG. 37 shows another example of the graph display. In FIG. 37, the abscissa represents the foreign matter size, and the ordinate represents the accumulated foreign matter. A curve 3701 of the accumulated foreign matter and a straight line 3702 indicating the position on the graph of the controlled foreign matter size in the semiconductor device manufacturing line and the controlled foreign matter. In this example, a size value 3703 is also shown. Here, the cumulative number of foreign matter is the total number of foreign matter of each size or smaller.

Further, FIG. 38 shows another example of the graph display. FIG. 38 is an example in which the horizontal axis represents the foreign matter size and the vertical axis represents the foreign matter cumulative rate, and the foreign matter cumulative rate curve 3801 and the foreign matter number rates 3802 and 3803 above a certain foreign matter size are shown together. Here, the cumulative percentage of foreign substances is the ratio of the number of foreign substances of each size or less to the total number of foreign substances detected by the inspection. Further, the ratios of the number of foreign substances 3802 and 3803 are the ratio of the number of foreign substances having a certain size or more to the total number of foreign substances detected by the inspection. For example,
The ratio 3802 of the number of foreign substances indicates that the ratio of foreign substances of 0.5 μm or more is 1, that is, all the detected foreign substances are 0.5 μm or more. In addition, the ratio of the number of foreign matters 3803
Is the ratio of foreign matter of 1.0 μm or more is 0.45, that is,
Forty-five percent of the total number of detected foreign matters is 1.0 µm or more.

Further, FIG. 39 shows another example of the graph display. FIG. 39 shows an example in which the abscissa represents the size of foreign matter and the ordinate represents the number of foreign matter in each size, and the abscissa represents logarithmic display.

Furthermore, FIG. 40 shows another example of the graph display. FIG. 40 is an example in which the foreign substance size is set on the horizontal axis and the number of foreign substances in each foreign substance size is set on the vertical axis, and a foreign substance number distribution 4001 and an average foreign substance number distribution 4002 are shown together. Here, the foreign substance distribution 4001 is the distribution of the number of foreign substances detected in one inspection, and the average foreign substance number distribution 4002 is the average value of the number of detected foreign substances when another wafer is inspected.

FIG. 20 shows another example of the graph display. Although the data for one wafer is displayed in the example of FIG. 7, the data for a plurality of wafers may be displayed side by side as shown in FIG. In addition, in FIG. 20, among the three coordinate axes,
The number of foreign matter detected on one axis, the foreign matter size on another axis,
In this example, the number of the wafer is set on another axis. In this example, the data range of the foreign matter size is set in units of 0.1 μm from 0 to 1 μm, all 1 μm or more are counted by the same bar graph, and the total number of detected foreign matters is also displayed. Also in this case, as in the case of FIG. 6, the average value, the standard deviation value, and the dispersion value of the foreign matter data for a plurality of sheets may be displayed.

Further, FIG. 21 shows another example of the graph display. FIG. 21 shows an example in which display data is displayed separately for foreign matter and scratches. FIG. 21 shows an example in which foreign substances and flaws are displayed, and further foreign substances and defect sizes are displayed.

Although the graph showing the relationship between the size of the foreign matter and the detected number has been described above, the display content desired to be used in one drawing may be used in combination with the display content in another drawing.

The function of displaying the detected position information of the foreign matter will be described. FIG. 8A shows the position information of all the detected foreign matters detected by the foreign matter inspection.

This figure shows that the detected foreign matter 702 exists on the outer shape 701 of the 8-inch semiconductor wafer, for example. At this time, if the bar graph 601 in FIG. 7 is clicked or double-clicked,
The section of the bar graph 601, that is, 2.8 μm to 3.0
A function for changing the display of the foreign matter 703 of μm as shown in FIG. 8B is provided. This makes it possible to quickly grasp the position of the foreign matter of a specific size on the inspection object 102.

FIG. 22 shows an example of displaying the inspection result after the foreign matter inspection. FIG. 22 is an inspection map 2201 showing the detection positions of foreign matter, and a histogram 22 of the size of the detected foreign matter.
02, a review button 2203, a review image 2204 of the detected foreign substance, a foreign substance 2205, and a data section 2206 of the size of the foreign substance to be reviewed, and the review image 2204 displays an image centering on the foreign substance 2205. . Further, in this example, a foreign matter having a size of 2.8 μm to 3.0 μm is selected as the data section 2206. In operation, first, a foreign matter is inspected by the defect inspection apparatus of the present invention, and then an inspection map 2201 as the foreign matter position information and a histogram 220 as the foreign matter size information.
Display 2. Then, the data section 2206 is selected as the size of the foreign matter to be reviewed, and the review button 22
By pressing 03, the review image 2204 obtained by the defect inspection apparatus of the present invention is displayed. Here, the review image 2204 may be an image by laser scattered light or an image by a microscope. Further, the position of the foreign matter displayed in the review image 2204 may be displayed together on the inspection map 2201, or the foreign matter number added by the defect inspection apparatus of the present invention may be displayed together.

FIG. 43 shows another example of the inspection result displayed after the foreign matter inspection. FIG. 43 is composed of an inspection map 4301 indicating the foreign matter detection position, a histogram 4302 of the detected foreign matter size, and a scroll bar 4303 for designating the foreign matter size of the foreign matter to be displayed. An example in which a foreign substance having a size of 0.1 μm to a foreign substance having a size of 3.0 μm can be adjusted is shown. Further, FIG. 43A shows the case where the button of the scroll bar 4303 is located at the leftmost position, and FIG. 43B shows the case where the button of the scroll bar 4303 is located at 2.2 μm. It is an example.

In operation, first, after the foreign matter is inspected by the defect inspection apparatus of the present invention, the inspection map 4301 as the foreign matter position information and the histogram 43 as the foreign matter size information.
02 and scroll bar 4303 are displayed. This is the state of FIG. 43 (a). The size of the foreign matter to be displayed is set to 2.2 μm or more in FIG.
It is (b). For the setting method, scroll bar 4303
It is sufficient to move the button in the state of FIG. 43 (a) to the right with a mouse or the like to move it to the position of 2.2 μm. At this time, the display of the foreign matter displayed on the inspection map 4301 is changed according to the movement of the button on the scroll bar 4303.
For example, in the case of FIG. 43B, the scroll bar 430
1 is at a position of 2.2 μm, the inspection map 4301
Shows only foreign matter of 2.2 μm or more. Also,
At the same time, a histogram 4302 of the size of the detected foreign matter
Among them, the color of the part of the foreign matter of 2.2 μm or more and the part of the foreign matter of less than 2.2 μm are changed. By changing the displayed foreign matter as described above, the distribution of foreign matter of each size can be quickly understood.

In this example, the inspection map 4301 has been described by way of an example in which only the foreign matter having a size larger than the designated size is displayed, but the foreign matter having a size smaller than the designated size may be displayed, and the foreign matter having a size larger than the designated size may be displayed. It is only necessary to be able to distinguish the foreign matter from other foreign matter. For example, the display color, shape, or size may be changed, or the foreign matter mark may be blinked. The advantage of each is that when only the specified foreign matter is displayed, it is easy to understand where the specified foreign matter exists, and when other foreign matter is also displayed, the positional relationship for all foreign matter is shown. It is easy to understand. Also, in the histogram 4302, it is sufficient that the foreign matter having a size larger than the designated size and the other foreign matter can be distinguished. Further, although the example using the scroll bar 4303 has been described in the present example, any other method capable of designating the size of the foreign matter may be used. For example, a screen for entering a numerical value may be used. Also,
In this example, the example of displaying the foreign matter of the designated size or more is described, but as another display example, only the foreign matter of the designated size may be displayed, or the foreign matter of the designated size or less may be displayed. You may.

Next, FIG. 49 and FIG. 5 show display examples in which position information and defect size information in the case of being classified into a foreign matter and a flaw are described together.
It shows in 0.

FIG. 49 is a graph 4901 plotting characteristic amounts obtained by the defect inspection apparatus of the present invention, position information 4902 of detected foreign matters or defects, the number 4903 of detected foreign matters or defects, and size of detected foreign matters or defects. Of the histogram 4904. In this example, a case where a flaw is detected as a defect is shown.

Specifically, the feature amount used in the graph 4901 is, for example, the respective scattered light amounts of the epi-illumination light and the oblique illumination light as described with reference to FIG. Further, a curve 4905 is a discrimination threshold value for classifying foreign matters and scratches in the graph 4901. Further, position information 4902 indicates the position of the foreign matter or scratch on the inspection object. In this example, the foreign matter is indicated by ◯ and the flaw is indicated by ▲. The detected number 4903 is the number of detected foreign matters or scratches. Further, a graph 4904 is a histogram of the number of detected foreign matters or scratches and their size. By displaying the objects detected by the defect inspection apparatus of the present invention in this way, the distribution of foreign particles or defects can be seen at a glance.

Next, FIG. 50 comprises position information 5001 of foreign matters or defects detected by the defect inspection apparatus of the present invention, a detection number ratio 5002 of foreign matters or defects, and a density graph 5003 of the size of a particular foreign matter or defect. Has been done. In this example, a pattern defect is displayed as a defect.

More specifically, the position information 5001 indicates the position of the foreign matter or pattern defect, and the frame line 5004 indicates the portion where the foreign matter or pattern defect is dense.
At this time, it can be determined whether or not the foreign matters or defects are dense, for example, by determining whether or not there are a plurality of foreign matters or defects within a certain area. You can judge that there is. In addition, the detected number ratio is 5
Reference numeral 002 indicates the detected number ratio of foreign matters or pattern defects, and the area in the circle graph corresponds to the detected number ratio. This makes it possible to easily understand the proportion of foreign matter or defects detected by the defect inspection apparatus of the present invention. Furthermore, the density and size graph 5003 of foreign matter or defects
Indicates the density and size distribution of the foreign matter or defect in the portion where the above-mentioned foreign matter or defect is dense, that is, the portion surrounded by the frame line 5004. As a result, the density and size of the foreign matter or defect in the dense portion can be easily grasped.

Next, referring to FIG. 9, a management method when the size of a specific foreign substance is time-series collected will be described.

Here, FIG. 9A shows a time-series transition of the total sum of all foreign substances of any size detected by the foreign substance detection device, for wafers of the same process processed by the same manufacturing device. FIG. 9C shows the transition of the sum total of the foreign matters having the size of 2.8 to 3.0 [μm] shown in the example of FIG. 7 for each time series. It is assumed that FIG. 9B shows the transition of the total sum of foreign substances of other sizes for each time series.

Threshold values 1001, 1002, 10
Reference numeral 03 denotes a management reference value for the number of foreign matters, and indicates that if more foreign matters than the threshold values are detected, the wafer is diagnosed as abnormal. That is, in FIG. 9A, it is determined that the peak value 1004 around the inspection time point A indicates an abnormality.

However, with only the statistics in FIG. 9A,
It is conjectured that some abnormality has occurred, but it is difficult to investigate the cause.

On the other hand, when the size of the foreign matter is controlled according to the size by the inspection method of the present invention, a remarkable peak 1005 is seen at time A in FIG. 9C, and the lot inspected at this time is 2.8. It can be seen that foreign matters having a size of up to 3.0 [μm] are particularly concentrated. Therefore, in FIG. 10 (b), there is no portion that exceeds the threshold value, and in FIG. 10 (c), the peak value 1005 is detected, and for the reason shown in FIG. It can be presumed that the fact that the pattern of this size peeled off was the cause of the particularly large amount of foreign matter, and it became possible to promptly take effective defect countermeasures such as inspecting the etching apparatus.

Next, an example in which the cause of failure is displayed to the user will be described with reference to FIG.

The defect inspection apparatus according to the present invention has a function of analyzing the size of a foreign substance and the number of detected foreign substances and displaying the cause of the defect to the user.

For example, it is assumed that the defect causes shown in FIG. 5C are taken as a model and the inspection result is obtained as the result shown in the graph of FIG. The section d to e in FIG. 5 corresponds to 2.8 μm to 3.0 μm in FIG. 7. Therefore, when the inspection result shown in FIG. 7 is obtained, the screen shown in FIG. 9 is displayed to clearly show the analysis result of the cause of the defect to the user.

[Foreign Particle Management Method] Next, another example of a management method using the size of a foreign material will be described. The foreign substances detected by the inspection device include foreign substances that cause defects and foreign substances that do not cause defects. That is, when the foreign matter is small with respect to the wiring width of the wiring pattern formed on the wafer and the space between the wirings, the foreign matter often does not cause a defect. Therefore, with respect to the detected size of the foreign matter, a foreign matter having a certain size or more may be managed as a foreign matter causing a defect.

Next, an example of a method of calculating the size of the foreign matter to be managed will be described. In FIG. 23, the wiring width on the wafer is W
The relationship between the first wiring pattern 2401 and the wiring pattern 2402 having the wiring width W2, the wiring pattern 2403 having the wiring width W3, and the foreign substance 2404 is shown. This foreign object 2404
Is a conductive foreign substance, and if the foreign substance 2404 exists at a position 2405 that straddles the wiring pattern 2401 and the wiring pattern 2402, the wiring pattern 2401 and the wiring pattern 2402 are short-circuited via the foreign substance 2404, and this chip is It becomes defective. Therefore, the distance between the wiring pattern 2401 and the wiring pattern 2402 is S
1. If the distance between the wiring pattern 2402 and the wiring pattern 2403 is S2, the size of the foreign material 2404 that may short-circuit the wiring pattern 2402 and other wiring is S1 or a foreign material having a size of S2 or more. ,In particular,
A foreign substance having a size of (S1 + W2 + S2) or more short-circuits the wiring with a probability of 100%.

Therefore, when the width of the wiring pattern and the distance between the wirings are the above-mentioned sizes, the size of the foreign matter causing the defect is a foreign matter having a size greater than or equal to the size given by MIN (S1, S2). Where MIN
(A, B) indicates that it is the smaller value when A and B are compared.

However, although an example of calculating the most severe condition for management is shown here, a larger foreign substance may be managed when managing under more lenient conditions.

The size of the foreign matter to be controlled in each manufacturing process is determined by the above calculation, and the variation in the number of detected foreign matters larger than the size to be controlled is monitored, so that the occurrence of defects can be detected promptly. It becomes possible to do. Here, as a monitoring method, for example, the average value and the standard deviation of the number of foreign substances to be controlled detected on several to several tens of wafers are calculated, and the monitoring threshold value = average value. It is only necessary to monitor the number of foreign particles with a monitoring threshold value calculated by + k × standard deviation, and to analyze the cause of defects and take countermeasures for wafers that exceed the monitoring threshold value. Here, k is a constant, and, for example, when it is desired that the number of wafers to be subjected to failure analysis be about 0.3% of all wafers, k = 3 may be calculated.

Next, another method for calculating the size of the foreign matter to be managed will be described. This is the presence / absence of foreign matter detected on one wafer and the good chips of the chip in which the foreign matter is detected.
This is a method in which the influence of foreign matter on the yield of wafers is calculated from defective products, and the calculated value is controlled by the size of the foreign matter.

FIG. 2 shows the calculation method of the influence on the yield.
This will be described using 9. FIG. 29 is a diagram showing presence / absence of foreign matter and category classification of non-defective / defective chips of the chips on the wafer. The chips 3001 (hereinafter Then Gn
A chip 3002 in which no foreign matter is detected and which is a defective product (hereinafter referred to as Bn), a chip in which a foreign matter is detected, and a chip 3003 which is a non-defective product (hereinafter, referred to as Bn). Will be referred to as Gp), and the chip 3 is a chip in which foreign matter is detected and which is a defective product.
004 (hereinafter referred to as Bp). Here, whether or not the foreign matter is detected in a certain chip may be determined, for example, based on the position information in the inspection result of the defect inspection apparatus of the present invention, and whether or not the certain chip is a non-defective product. For the determination, for example, the result of the electrical inspection may be used.

First, when the yield of a certain wafer is Y and the yield of chips in which no foreign matter is detected is Yn, the influence of the detected foreign matter on the yield of the wafer dY is defined as dY = Yn-Y. . Since Y is the yield of wafers, Yp is the yield of chips in which foreign matter is detected, and γ is the ratio of chips in which foreign matter is detected to the total number of chips (hereinafter referred to as foreign matter generation frequency). It can be expressed as × (1-γ) + Yp × γ.

Here, the above-mentioned Gn, Bn, Gp, Bp
Can be expressed as Y = (Gn + Gp) / (Gn + Bn + Gp + Bp) Yn = Gn / (Gn + Bn) Yp = Gp / (Gp + Bp) γ = (Gp + Bp) / (Gn + Bn + Gp + Bp), respectively.

Therefore, dY is expressed as dY = Yn-Y = Yn- (Yn * (1- [gamma]) + Yp * [gamma]) = (Yn-Yp) * [gamma] = Yn * (1-Yp / Yn) * [gamma]. You can Here, if the probability that a chip is defective due to a foreign substance is F (hereinafter referred to as a fatal rate), it can be expressed as Yp = Yn × (1−F). Therefore, if rewritten, F = 1−Yp / Since it is Yn, it can be expressed as dY = Yn × F × γ.

Here, the foreign matter generation rate γ has a larger value as the foreign matter detection sensitivity is higher, and has a smaller value as the foreign matter detection sensitivity is lower. This is because the higher the detection sensitivity is, the more foreign matter is detected. Further, the fatality rate F has a smaller value as the foreign matter detection sensitivity is higher, and has a larger value as the foreign matter detection sensitivity is lower. This is because the higher the detection sensitivity is, the finer the foreign matter is detected, but as described above, when the foreign matter is smaller than the distance between the wiring patterns, a defect such as a short circuit does not occur.

Therefore, when calculating the influence dY on the yield, the size of the foreign matter used for the calculation should be limited, and the size of the foreign matter that maximizes the influence on the yield dY should be controlled. The smallest foreign material size. Here, limiting the size of the foreign material means that the data of the foreign material having a certain size or more is used.

Details will be described with reference to FIG. In FIG. 51, a graph 5101 is a diagram in which the vertical axis is the yield influence dY, and the horizontal axis is the foreign matter size threshold value. Here, the foreign matter size threshold value is used as a term indicating all foreign matter having a certain size or more. That is, in FIG. 51, the foreign matter size threshold value 5102 shows the case where the data of the foreign matter size “A” μm or more is used for the calculation, and the calculated value of the influence on the yield at this time is the point 5103,
Also, the foreign matter detection result at this time, that is, the foreign matter size "A"
The foreign matter detection result of μm or more indicates the inspection result 5104.

Similarly, the foreign matter size threshold value 510
5 shows the case where the data of the foreign matter size “B” μm or more is used, the calculated value of the influence on the yield is the point 5106, and the foreign matter detection result at that time is the inspection result 5107. Further, the foreign matter size threshold value 5108 is the foreign matter size “C” μ.
The case where data of m or more is used is shown. The calculated value of the influence on the yield is point 5109, and the foreign matter detection result at that time is the inspection result 5110.

A graph 5111 is obtained by calculating the above-mentioned influence on the yield with each foreign matter size threshold value. Since this graph 5111 is calculated by the above-described method, it corresponds to the influence of each foreign matter size on the yield. Therefore, it can be said that the foreign matter size threshold value that greatly affects the yield is the foreign matter size that can efficiently extract the foreign matter that affects the yield, and is the foreign matter size that should be managed in the device manufacturing line. That is, in FIG. 51, since the plot point 5112 on the graph 5111 indicates the maximum value of the calculated values,
The above-mentioned minimum foreign matter size to be managed is the foreign matter size threshold value 5113.

FIG. 24 shows an example of the result of calculating the influence dY on the yield. In FIG. 24, the vertical axis represents the influence on the yield d.
Y and the horizontal axis indicate the size of the foreign material used when the influence dY on the yield was calculated. For example, in FIG. 24, the point 2501 indicates that the yield effect dY is 0.1 as a result of calculation using the foreign substance data of 0.1 μm or more, and the point 2502 indicates 0.4 μm or more. As a result of calculation using the foreign substance data, the effect on yield dY
Indicates that it is 0.8. Where 0.1 μm
The use of the above-mentioned foreign matter data means that, of the detected foreign matter, the chip in which the foreign matter of 0.1 μm or more is detected is regarded as the chip in which the foreign matter exists, and the foreign matter of less than 0.1 μm is detected, or This indicates that a chip in which no foreign matter is detected is calculated as a chip in which no foreign matter exists. Therefore, according to FIG. 24, when the calculation is performed by using the data of the foreign matter of 0.4 μm or more, the most influence on the yield dY
Is calculated to be large, so it is sufficient to manage with a foreign substance of 0.4 μm or more.

FIG. 52 shows an example in which the influence dY on the yield is displayed for each process. FIG. 52 is a graph 5201 calculated with the data of the process 1 and a graph 520 calculated with the data of the process 2.
2 and management size display 5203 are also shown. In the example of FIG. 52, the process 1 is a case where the foreign matter of 0.3 μm or more should be controlled, and the step 2 is a case where the foreign matter of 0.7 μm or more should be controlled.

However, in this example, the size of the foreign matter is set to 0.1 μm.
Although an example in which the value is changed in m units is shown, other values may be set in 0.2 μm units or other values. Further, in the present embodiment, as the method of determining the size of the foreign matter to be managed, the example in which the influence dY on the yield is determined to be the maximum is described, but the size of the foreign matter is not necessarily the maximum. The influence on the yield may be a value close to the maximum value of dY, that is, the size of the foreign matter which is approximately the maximum value × 0.9 or more.

FIG. 33 shows another example of the calculation result. FIG. 33
Shows the calculation result of the influence dY on the yield and the foreign matter detection map at that time. FIG. 33A is an example in which the influence dY on the yield is calculated in units of about 0.07 μm and the value on the vertical axis is displayed in percentage. 33 (b) is a foreign matter detection map displaying all the foreign matter detected by the defect inspection apparatus of the present invention, and FIG.
Is a foreign matter detection map in which a foreign matter having a size of 1.1 μm or more is extracted. This value of 1.1 μm is shown in FIG.
Is the value at which the effect on yield, dY, becomes maximum.
Therefore, it is sufficient to manage the foreign matter based on the foreign matter detection map of FIG. 33 (c).

In this example, the data of one wafer is described, but the yield influence dY is calculated from the data of a plurality of wafers, and the average value of the respective values is calculated as the representative value of the yield influence dY. Also good. In this case, there is an advantage that erroneous evaluation due to unique wafer data can be reduced. In addition, the size of each foreign substance to be managed is calculated from the data of multiple wafers, and the smallest value among the calculated values from the data of multiple wafers is the size of the foreign substance to be managed in that process. Also good. In this case, it is possible to perform stricter control than judgment based on the data of one wafer, which can lead to improvement in quality of semiconductor devices.

Further, when the number of chips on the wafer is small, the accuracy of calculation of the degree of influence dY on yield may decrease. Therefore, when calculating the degree of influence dY on yield, data of a plurality of wafers is used. It may be calculated by

Next, a method of controlling the semiconductor device manufacturing process when the above-described yield effect dY is used will be described. FIG. 25 is a graph in which the above-mentioned yield influence dY is set on the vertical axis and the semiconductor manufacturing process is set on the horizontal axis. The abscissa indicates the process inspected by the foreign matter and defect inspection apparatus of the present invention.

Next, the operation will be described. First, the same wafer is used to perform an inspection in each process shown on the horizontal axis. Next, when it is determined whether each chip of the wafer is a good product or a defective product, the above-mentioned yield influence dY is calculated for each process. FIG. 25 is an example in which the yield influence dY is calculated in each process. For example, a point 2601 indicates that the yield influence dY calculated by the foreign matter detected in the process of step 4 was 0.8. ing. As described above, the yield influence dY is calculated in each process, and the process having a larger yield influence dY value is preferentially taken, so that the yield influence is large in the semiconductor manufacturing process. Measures can be taken from processes that are most likely to be the cause of defects.

In the above example, the case where all the data of the foreign matter detected in each process is used is explained. However, for the foreign matter which is known to be generated in a different process, the data of the foreign matter is used. The influence dY on the yield may be calculated using the remaining data that has been removed. As a method of excluding data, for example, in FIG. 25, the position information of the foreign matter detected in step 1 is compared with the position information of the foreign matter detected in step 2, and the foreign matter already detected in step 1 is It may be deleted from the foreign matter data in step 2.

Further, in the above example, the influence on the yield d
Although the evaluation method using dY = Yn × F × γ as Y has been described, in addition to the above, when performing evaluation when defects due to the process are eliminated, the above Yn = 1 and dY = F × γ may be used, or this method can be applied to any other index for calculating the influence of foreign matter. For example, in a memory product such as DRAM, the number of defective bits of each foreign matter is used as an index. Is also good. Further, for example, when paying attention to the chip in which the foreign matter is detected, the good product rate of the chip in which the foreign matter is detected, that is, the above Yp may be used as an index, and the number of the chips in which the foreign matter is detected, that is, The above γ may be used as an index, and the fatality rate F may be used as an index. When these indexes are used, Yp and F have an advantage that the influence of the foreign matter can be directly calculated, and γ has an advantage that they can be calculated immediately after the inspection. Furthermore, the value of (Y-Yp) may be used as an index, and the value of (Yn-Yp) may be used as an index.

FIG. 53 shows an example in which dY, F and γ are calculated and displayed. In FIG. 53, a graph 5301 is a calculated value of the yield influence dY, and a graph 5302 is a calculated value of the fatality rate F. A graph 5303 is a calculated value of the ratio γ of the number of chips in which foreign matter is detected.

Further, in this example, the foreign material data of a certain size or more is used as the data for calculating the influence dY on the yield, but the foreign material data of a specific size may be used for the calculation. In this case, it is possible to evaluate the influence on the foreign matter of a specific size, and thus it is possible to perform a precise evaluation.

Also, the influence dY on the yield may be calculated for each shape of the above-mentioned foreign matter. In this case, there is an advantage that efficient measures can be taken. In other words, it is often related to the shape of the foreign matter and the cause of the generation, and it is important to determine the shape of the foreign matter to be taken as a countermeasure. By taking measures, it is possible to efficiently take measures against defects in semiconductor devices.

Further, in the above-described embodiment, the example described with reference to FIG. 23 needs only the information of the width of the wiring pattern of the semiconductor device and the width of the space, so that the management is performed when the design of the semiconductor device is decided. There is a merit that the size of the foreign matter to be determined can be determined. For it,
The example described with reference to FIG. 29 is an index that takes into account information such as a wiring short circuit due to the height of the foreign matter as well as the width of the foreign matter, and has an advantage that it represents the actual device state.

Next, FIG. 54 shows a display example using the above-mentioned yield influence dY. FIG. 54 is a diagram in which the foreign matter size threshold value is arranged on the horizontal axis and the influence on the yield is arranged on the vertical axis.
Graph 5401, detection result 5402, and detection number 54
It is composed of 03.

In FIG. 54, a graph 5401 is a graph connecting the calculated values of the influence on the yield at each foreign substance threshold value. In addition, the detection result 5402 and the detected number 54
Reference numeral 03 denotes the foreign substance detection result and the number of detected foreign substances at the foreign substance size threshold value 5404. In this example, the example in which only one set of the detection result and the number of detections is displayed has been described, but the detection result and the number of detections at other foreign matter size thresholds may be displayed together.

The method for determining the size to be managed from the detected foreign matter has been described above, but the present method can be applied regardless of whether or not a detected matter other than the foreign matter or defect exists. That is, this is an effective method not only when the defect inspection apparatus inspects a normal pattern under the condition that the normal pattern is not erroneously detected, but also under the condition where the normal pattern is erroneously detected. Therefore, it is not necessary to strictly set the inspection conditions of the defect inspection apparatus, and there is an advantage that the operation of setting the inspection conditions is simple or unnecessary.

[Inspection of foreign matter by area and analysis of cause of defect]
Next, an example will be described in which the defect inspection apparatus of the present invention manages foreign matter data for each area on a wafer and takes countermeasures against defects.

FIG. 11 is a diagram schematically showing a region of a semiconductor wafer.

FIG. 12 is a schematic diagram explicitly showing foreign matter of a specific size on the wafer when foreign matter data is managed for each area.

FIG. 13 and FIG. 14 are graphs showing the detected number of foreign matters by size of each area.

Generally, when a chip pattern is formed on a semiconductor wafer, the pattern is not always formed uniformly, and the pattern formation density is high in some areas and low in some areas. For example, assuming that the chip shown in FIG. 11 is a microprocessor, for example, the area 1101 is a memory cell circuit portion and the area 1102.
Is a data input / output circuit portion, and the area 1103 is a portion where no circuit pattern exists. Usually, the degree of integration of circuit patterns is different in these areas 1101, 1102, 1103. Therefore, as a result, the size of the foreign matter that causes a defect also differs in each region. That is, the size of the foreign matter to be managed / analyzed differs depending on the area within the chip. Specifically, for example, in the region 1101, foreign matter having a size α or more is defective, in the region 1102, foreign matter having a size β or more, and in the region 1103, foreign matter having a size γ or more is defective. In such a case, the area information and the size information of the defective foreign matter are stored in the inspection apparatus in advance as management data. As a method of inputting the area information and the size information of the defective foreign matter, a screen for inputting coordinate values and the size of the foreign matter may be provided directly in the inspection apparatus, or the optical image of the wafer may be input by a TV camera or the like. The area may be selected from the input image. Further, the data may be downloaded from the host system, or the data may be read into the inspection device from a removable storage medium, for example, a floppy (registered trademark) disk.

[0187] As described above, the inspection device is inspected with the area and the size information of the foreign matter determined to be defective. Then, the area is determined based on the position information of the detected foreign matter in the inspection device, and the size information of the detected foreign matter is compared with the size information of the defective foreign matter to determine whether or not it causes the defect.

As a result, by changing the output display form of the foreign matter determined to cause the defect and the foreign matter determined not to cause the defect, the foreign matter causing the defect is clearly indicated to the user, and the user causes the defect. Foreign objects can be seen immediately.

This method will be concretely described with reference to FIG.

On the wafer 1201 shown in FIG. 12, the position of the detected foreign matter 1202 is shown and output. Conventionally, since the detection result is as shown in FIG. 12A, a foreign substance is appropriately selected and analyzed for the cause of the failure. Therefore, the probability that a foreign substance to be truly analyzed can be selected is low, and it takes time to analyze the cause of the defect. However, as shown in FIG. 12B using the previous determination, the foreign matter determined to cause the defect, that is,
By changing the display of the foreign matter 1203 to be analyzed,
The foreign matter 1203 to be analyzed can be easily selected from the detected foreign matter, the probability of selecting the foreign matter to be analyzed is increased, and the cause of the failure can be analyzed quickly. Although the display pattern is changed in FIG. 11 to change the display, the color or size of the display pattern may be changed. Further, it is possible to display only the foreign matter that causes the defect. Further, in the present embodiment, the area division within the chip is performed as the area division, but this is divided into areas within the wafer surface, for example, the area division is performed according to the distance from the wafer center to the wafer edge for management. The size of the foreign matter may be changed. Further, the layout of the semiconductor chips may be displayed on the wafer shape 1201.

Next, a method for taking measures against defects by grasping the detected number of foreign matters for each area with reference to FIGS. 13 and 14 will be described.

In this example, one wafer is classified into three areas. Suppose that the area is an area A, an area B, and an area C, and the number of foreign matters is detected for each area. Then, the result is displayed to the user as a graph for each area.

For example, as shown in FIG. 13, the horizontal axis represents the size of the foreign matter, and the vertical axis represents the detected number of the foreign matter. Color coding is performed for each of the areas A, B, and C to determine the foreign matter. Display the graphs side by side according to size category.

Further, as shown in FIG. 14, it may be displayed in a graph by vertically arranging for each category of the size of the foreign matter.

Specifically, for example, in the case of a semiconductor wafer, the three regions are, for example, a memory cell circuit portion, a circuit portion other than the memory cell circuit, and a portion having no circuit pattern. Displaying as shown in FIGS. 13 and 14 makes it easy to manage foreign matter in each area. Here, as a method of inputting the area information, a screen for inputting coordinate values and the size of the foreign matter may be provided in the inspection device and may be directly input,
A region may be selected from an image obtained by inputting an optical image of a wafer with a TV camera or the like. Further, the data may be downloaded from the host system, or the data may be read into the inspection device from a removable storage medium such as a floppy disk.

Now, a method of finding the defective product by counting the number of detected foreign matters of each size for each area will be described.

As described above, the size of a foreign substance which is determined to be defective when the foreign substance exists in each region is different. In a certain area, since it is not a very fine circuit, a relatively large foreign matter will not be regarded as a defect, and in a certain area, a fine circuit and a relatively small foreign matter may cause trouble. . In this way, the thresholds for issuing warnings for each area are set to α, β, and γ for each of the areas A, B, and C, and α = 1.0 in the examples shown in FIGS. 13 and 14, for example. [Μm] β = 1.6 [μm] γ = 2.0 [μm].

According to this, the total sum of the numbers of foreign matters detected with the size exceeding the threshold value for each area is as follows.

Area A ... 24 areas B ... 3 areas C ... 1 Therefore, the foreign matter detected in the area C is apparently
Although they are very large, they do not affect the quality of the product so much, while the area A is the area C.
Although the number of foreign substances is not so large, the quality of the product is likely to be affected, and therefore it can be said that the foreign substances attached to the area A have a high probability of being determined as a defective product. In this way, by setting a threshold value that is regarded as a defect of foreign matter for each area, the total number of detected foreign matter exceeding them is obtained, and the good or bad of the object to be inspected is determined and the fact is displayed to the user. As a result, a rational inspection can be performed according to the characteristics of the area.

[Apparatus Performance Evaluation Method Using Foreign Particle Size]
Next, an evaluation method of the inspection device using the present invention will be described.

FIG. 55 is a diagram in which the influence on the yield is calculated for each device or each detection sensitivity. FIG. 55 is a graph in which the above-mentioned influence on the yield is arranged on the vertical axis and the foreign matter size threshold value is arranged on the horizontal axis. In FIG. 55 (a), the calculation graph 5501 and the inspection apparatus in the inspection apparatus A are shown. Calculation graph 550 in B
2, FIG. 55 (b) is a calculation graph 55 in the inspection apparatus A.
01 and the calculation graph 5503 of the inspection apparatus C.

Next, the evaluation method will be described. First, the same inspection object is inspected with respect to the inspection apparatus to be evaluated, and the graph of the influence on the yield according to the foreign matter size threshold value in FIG. 55 is created. An example of creating a graph at this time is shown in FIGS. 55 (a) and 55 (b).

FIG. 55A shows an example in which a calculation graph 5501 in the inspection apparatus A and a calculation graph 5502 in the inspection apparatus B are created. In FIG. 55A, the minimum foreign matter size threshold is about 0.6 μm in both of the inspection devices, but the inspection device A has a larger effect on the yield. This is because the inspection apparatus A detects more foreign matter that affects the yield. That is, the inspection device B is the inspection device A.
It can be said that the rate of capturing foreign matter is lower. Therefore, the inspection apparatus A is more suitable than the inspection apparatus B for the inspection object used in this example.

Next, FIG. 55B shows an example in which a calculation graph 5501 in the inspection apparatus A and a calculation graph 5503 in the inspection apparatus C are created. In FIG. 55 (b), the influence on the yield of either inspection device is about the same value until the foreign matter size threshold is about 1.3 μm. However, the inspection apparatus C does not have data of a portion where the foreign matter size threshold value is smaller than 1.3 μm. This is because the inspection device C does not detect foreign matter smaller than 1.3 μm. That is,
It can be said that the inspection device C lacks in detection sensitivity. Therefore, the inspection apparatus A is more suitable than the inspection apparatus B for the inspection object used in this example.

The performance of the inspection apparatus can be evaluated as described above. Furthermore, by performing this evaluation in each process, it is possible to select the optimum inspection device for each process.

In the above example, the evaluation method in which a graph is created has been described as an example, but it is not always necessary to create a graph, and the maximum value of the influence on the yield may be obtained and the evaluation may be performed using this value. Further, in this example, the influence on the yield is used as the evaluation index, but the evaluation may be performed using another evaluation index used at the time of explaining the method of determining the controlled foreign matter size.
If the inspection apparatus to be evaluated does not have the function of outputting the size of the foreign matter or defect, the review apparatus may review the detection result of the inspection apparatus to be evaluated to obtain the size of the foreign matter or defect.

FIG. 56 shows a display example when three inspection devices are evaluated. FIG. 56 is a graph in which the influence on the yield is calculated by three inspection devices.
Reference numerals 602 and 5603 are calculation results of the inspection devices. By displaying the calculation results of a plurality of inspection devices as shown in FIG. 56, the performance between the inspection devices can be easily grasped.

[Regarding Display] Regarding the display according to the present invention described above, it may be displayed on the defect inspection apparatus of the present invention, or may be displayed on a terminal connected to a host system. In this case, the advantage of displaying on the terminal of the host system is that the result can be viewed from any place connected to the host system.

[Regarding Optical System of Defect Inspecting Device] Above,
In the description of the present invention, regarding the optical system of the defect inspection apparatus,
Although the method of detecting a foreign substance by using scattered light and measuring the size thereof has been described, the technique of the present invention detects the foreign substance or defect by the optical system by the reflected light and measures the size thereof. Even if it is a thing, it is applicable. In general, the one using scattered light has a good inspection efficiency, but has a difficulty in measurement accuracy,
The one using reflected light is the opposite, and the efficiency of the inspection is poor, but the measurement accuracy is excellent. It means that the method of the present invention can be applied to both.

[0210]

According to the present invention, in conducting inspection and defect analysis in the manufacturing process of semiconductor wafers and thin film substrates, inspection and defect analysis according to the characteristics of foreign matters and patterns and the characteristics of the region of the object to be inspected. Therefore, it is possible to provide a defect inspection apparatus and a defect inspection method capable of promptly taking measures against defects.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a defect inspection apparatus according to the present invention.

FIG. 2 is a block diagram when operating the defect inspection apparatus according to the present invention as a system.

FIG. 3 is a diagram showing image data when a foreign substance is present and a diagram showing a distribution of signal intensity when the foreign substance data is measured.

FIG. 4 is a diagram comparing two types of signal intensity distributions and an explanatory diagram for obtaining the maximum value of signal intensity.

FIG. 5 is a diagram showing that the relationship between the size of foreign matter and the number of generated foreign matter changes depending on the cause of a defect.

FIG. 6 is a line graph showing the detected number of foreign matters and the size of the foreign matters.

FIG. 7 is a diagram showing a histogram of the number of detected foreign matters and the size of the foreign matters.

FIG. 8 is a plan view of a wafer showing a foreign matter of a specific size on the wafer.

FIG. 9 is a graph showing a transition of the number of detected particles for each size of a specific foreign matter in time series.

FIG. 10 is a front view of a screen for displaying a cause of a defect in which a foreign substance has occurred to a user.

FIG. 11 is a plan view schematically showing a region of a semiconductor wafer.

[FIG. 12] When foreign matter data is managed for each area,
It is a top view of the wafer which showed the foreign material of a specific size on the wafer explicitly.

FIG. 13 is a diagram showing a graph displaying the number of detected foreign matters by size of foreign matter by region (No. 1).

FIG. 14 is a diagram showing a graph displaying the number of detected foreign matters by size of foreign matter by area (No. 2).

FIG. 15 is a graph showing the relationship between the maximum value of signal intensity and the size of foreign matter in the defect inspection apparatus according to the present invention.

FIG. 16 is a block diagram when operating the defect inspection apparatus and the review apparatus according to the present invention as a system.

17A is a graph showing a distribution of saturated signal intensity on an XY plane, and FIG. 17B is a graph for explaining obtaining a maximum value of signal intensity.

FIG. 18A is a block diagram showing a schematic configuration of an apparatus for detecting foreign matter and scratches, and FIG. 18B is a diagram illustrating a method of determining foreign matter and scratches.

FIG. 19 is a block diagram illustrating a flow for calculating the size of a foreign substance when the determination of the foreign substance and the scratch is used.

FIG. 20 is a graph showing histograms of the number of detected foreign matters and the size of the foreign matters for a plurality of inspection objects.

FIG. 21 is a graph showing a histogram for each defect type and size.

FIG. 22 is a front view of a display screen showing an example of a display of the defect inspection apparatus according to the present invention.

FIG. 23 is a plan view of a wiring pattern for explaining the relationship between the wiring pattern and the size of foreign matter.

FIG. 24 is a graph illustrating the relationship between the detection sensitivity of the defect inspection apparatus according to the present invention and the influence of the detected foreign matter on the yield.

FIG. 25 is a diagram showing an example in which the influence on yield is calculated for each manufacturing process.

FIG. 26 is a histogram showing the relationship between the size of foreign particles and the number of detected particles when standard particles are measured by the defect inspection apparatus according to the present invention.

FIG. 27 is a histogram showing the relationship between the size of a foreign substance and the number of detected foreign substances before the size of the foreign substance is calibrated by the defect inspection apparatus according to the present invention.

FIG. 28 is a graph showing the relationship between the particle size measured by the inspection apparatus and the particle size measured by the SEM for explaining the method of calibrating the particle size by the defect inspection apparatus according to the present invention.

FIG. 29 is a plan view of a wafer illustrating a method of calculating the influence on the yield based on the presence or absence of foreign matter.

30 (a) and 30 (b) are graphs showing the correlation between the size of a foreign substance measured by the defect inspection apparatus according to the present invention and the SEM size (first).

FIG. 31 is a graph showing the correlation between the size of a foreign substance measured by the defect inspection apparatus according to the present invention and the SEM size, and an enlarged view of representative defects (No. 2).

FIG. 32 is a histogram showing the detected number of foreign particles measured by the defect inspection apparatus according to the present invention for each size.

FIG. 33 (a) is a graph showing the relationship between the size of foreign matter and the yield impact measured by the defect inspection apparatus according to the present invention;
FIG. 3B is a plan view of the wafer showing the distribution of all foreign matters, and FIG. 8C is a plan view of the wafer showing the distribution of foreign matters having a size of 1.1 μm or more.

FIG. 34 is a graph showing the relationship between the size of a foreign substance and the cumulative number of foreign substances in the defect inspection apparatus according to the present invention.

FIG. 35 is a graph showing the relationship between the size of foreign matter and the number of detections for each size, and an approximate curve in the defect inspection apparatus according to the present invention.

FIG. 36 is a graph showing the relationship between the foreign matter size and the foreign matter number ratio as an example of the foreign matter detection result displayed in the defect inspection apparatus according to the present invention.

FIG. 37 is a graph showing a relationship between a foreign particle size and a cumulative foreign particle number as an example of the foreign particle detection result displayed in the defect inspection apparatus according to the present invention.

FIG. 38 is a graph showing the relationship between the foreign particle size and the cumulative foreign particle number as an example of the foreign particle detection result displayed in the defect inspection apparatus according to the present invention.

FIG. 39 is a diagram showing a relationship between a foreign matter size and the number of detected foreign matter as an example of the foreign matter detection result displayed in the defect inspection apparatus according to the present invention.

FIG. 40 is a diagram showing a plurality of cases regarding a relationship between a foreign matter size and the number of detected foreign matter, as an example of the foreign matter detection result displayed in the defect inspection apparatus according to the present invention.

FIG. 41 is a graph showing the relationship between the size of the minimum detected foreign matter and the inspection area ratio in the defect inspection device according to the present invention.

42 (a) is a diagram showing an image of a foreign matter, and FIG. 42 (b) is a diagram showing a distribution of gray values of the image of (a).

43 (a) and (b) are front views of a display screen showing a display example of a detection result of a foreign matter according to the present invention.

FIG. 44 is a block diagram when operating the defect inspection apparatus according to the present invention as a system in a device manufacturing line.

FIG. 45 is a three-dimensional representation of a Gaussian distribution for explaining a method of correcting a saturated signal value.

46 (a) to (c) are graphs showing the relationship between the amount of scattered light by incident illumination and the amount of scattered light by oblique illumination of foreign matter and scratches.

[Fig. 47] Fig. 47 is a graph showing a display example in the case of determining a foreign substance and a scratch by using the characteristic amounts 1 and 2 or the characteristic amounts 3 and 4.

48A is a graph showing the relationship between the scattered light intensity from a foreign substance and the length measurement size, and FIG. 48B is a graph showing the relationship between the scattered light intensity from a defect and the length measurement size.

FIG. 49 is a front view of a display screen showing a display example when a foreign matter and a flaw are discriminated in the defect inspection apparatus according to the present invention.

FIG. 50 is a front view of a display screen showing another display example when a foreign matter and a flaw are discriminated in the defect inspection apparatus according to the present invention.

FIG. 51 is an explanatory diagram of a method for determining the controlled foreign matter size in the defect inspection apparatus according to the present invention.

FIG. 52 is a graph showing a relationship between a foreign matter size threshold value and a yield influence degree in the defect inspection apparatus according to the present invention.

FIG. 53 is a graph showing the relationship between the foreign matter size threshold value, the yield impact, the fatality rate, and the ratio of the number of chips in which foreign matter is detected in the defect inspection apparatus according to the present invention.

FIG. 54 is a graph showing a relationship between a foreign matter size threshold value and a yield influence degree in the defect inspection apparatus according to the present invention.

55A and 55B are graphs showing the relationship between the foreign matter size threshold value and the yield impact degree for each inspection device.

FIG. 56 is a graph showing the relationship between the foreign matter size threshold and the yield impact of three inspection devices in the defect inspection device according to the present invention.

[Explanation of symbols]

101 ... Illumination optical system 102 ... Inspected object 103 ...
Detection optical system 104 ... Photodetection unit 105 ... Signal processing circuit 106 ... Data display unit 107 ... Stage unit 108 ... Autofocus illumination unit 109 ...
Autofocus light receiving unit 201 ... Foreign object data 2
02 ... Waveform of foreign matter data 201 ... Maximum value of signal strength of foreign matter data 302 ... Saturation area of signal strength of foreign matter data 303 ... Saturation level of signal strength 304 ... Unsaturated data of signal strength of foreign matter data 401, 402, 403
... Distribution area of foreign matter 701 ... Outer shape of semiconductor wafer
1101, 1102, 1103 ... Area in chip 1
201 ... Semiconductor wafer 1201 ... Foreign matter to be analyzed on detection result 1301 ... Foreign matter inspection apparatus 1302 ... Data server 1303 ... Reviewing apparatus
1304 ... Electrical test equipment 1305 ... Analytical equipment
1306 ... Network connecting each device 1601 ... Inspection device 1602 ... Review device 1
Reference numeral 603 ... Network for connecting each device 1801 ...
Substrate 1802 ... Foreign matter 1803 ... Epi-illumination light
1804 ... Oblique illumination light 1805 ... Photodetector 18
06 ... Storage circuit 1807 ... Comparison circuit 1901 ... Signal strength storage unit
1902 ... Foreign matter / scratch discrimination section 1903 ... Conversion curve selection section 1904 ... Foreign matter size calculation section 2205 ... Foreign matter 2401 ... Wiring width W1 wiring pattern 2402 ... Wiring width W2 wiring pattern 2
403 ... Wiring pattern with wiring width W3 2404 ... Foreign matter, 2405 ... Foreign matter position across wiring pattern 300
1 ... A chip in which no foreign matter is detected and is a good product 3002 ... A chip in which no foreign matter is detected and is a defective product 300
3 ... Chip in which foreign matter is detected and is good product 3004 ... Chip in which foreign matter is detected and is defective product 4401 ... Semiconductor device manufacturing process 4402 ... Inspection process 44
03 ... Inspection device group 4404 ... Database 44
05 ... Measuring device group

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI Theme Coat (reference) H01L 21/66 H01L 21/66 J Z G01B 11/24 F (72) Minor Minoru Totsuka Yokohama, Kanagawa Prefecture 292 Yoshida-cho, Tokyo, Ltd., Production Engineering Laboratory, Hitachi, Ltd. (72) Inventor Yoshimasa Oshima, 292, Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture, Ltd., Production Engineering Laboratory, Hitachi, Ltd. (72) Inventor, Rei Hamamatsu Yokohama, Kanagawa 292, Yoshida-cho, Totsuka-ku, Ltd. Within the Hitachi, Ltd. Institute of Industrial Science (72), Inc. (72) Inventor Kenji Watanabe, 5-20-1, Josuihonmachi, Kodaira-shi, Tokyo Within the Hitachi, Ltd. semiconductor group (72) Inventor ▲ Tetsuya Tetsuya 3-16-3 Higashi, Shibuya-ku, Tokyo Inside Hitachi Electronics Engineering Co., Ltd. (72) Inventor Takahiro Jingu Tokyo Shibuya-ku, Higashi 3-chome 16th No. 3 Hitachi Electronics Engineering Co., Ltd. in the F-term (reference) 2F065 AA03 AA23 AA49 AA54 BB02 CC18 CC19 DD13 FF04 FF43 GG02 GG05 GG06 GG22 GG24 HH03 HH04 JJ02 JJ03 JJ16 JJ17 JJ19 JJ25 JJ26 LL08 LL09 LL22 LL32 QQ03 QQ13 QQ14 QQ18 QQ29 QQ43 QQ45 RR04 SS02 SS04 SS09 SS13 UU01 UU02 UU05 2G051 AA51 AB01 AB02 AC04 CB01 CB05 DA07 EB01 EC02 FA01 FA02 4M106 AA01 BA05 CA39 CA41 DA02 DJ20 DJ04 BA02 DJ20 DJ23 DJ02 DJ04 DJ06 DJ02 DJ04 DJ06 DJ06 DJ04 DJ06 DJ06 DJ02 DJ04 DJ06 DJ02 DJ04 DJ06 BA03 CA02 FA35 FA59 FA69 JA11

Claims (20)

[Claims] 1. A device for detecting a foreign matter defect or a pattern defect of an object to be inspected, comprising: illuminating means for irradiating the object to be inspected with light; and the object to be inspected by irradiating light from the illuminating means. Detecting means for detecting reflected light or scattered light of the light, detecting means for processing a signal obtained by detecting the reflected light or scattered light by the light detecting means to detect a foreign matter defect or a pattern defect, and the detecting means. Processing means for determining the size of the foreign matter defect or pattern defect using the information of the foreign matter defect or pattern defect detected by the means, and for determining the frequency of the obtained foreign matter defect or pattern defect size; A defect inspection apparatus comprising: an output unit that outputs information on the size of the obtained foreign matter defect or pattern defect and the occurrence frequency for each size. 2. The defect inspection apparatus according to claim 1, wherein the output means displays the information on the cause of the defect on the screen in association with the information on the size of the foreign matter defect or the pattern defect. 3. The display means discriminates, on the screen, information on a foreign matter defect or pattern defect of a specific size among the foreign matter defects or pattern defects from information on foreign matter defects or pattern defects of other sizes. The defect inspection apparatus according to claim 1, wherein 4. The processing means comprises an input section for inputting information of good / defective obtained by electrically inspecting the object to be inspected, and information of the result of the electrical inspection inputted to the input section and the processing. Calculating the degree of influence on the yield of the foreign matter defect or the pattern defect using the information on the size of the defect obtained by the means, and outputting the result of the degree of influence on the calculated yield from the output means. The defect inspection apparatus according to claim 1, wherein: 5. An apparatus for detecting a foreign matter defect or a pattern defect of an object to be inspected, comprising: illuminating means for irradiating the object to be inspected with light; and the object to be inspected by irradiating light from the illuminating means. And a signal obtained by detecting the reflected light or the scattered light by the light detecting means to divide the object to be inspected into a plurality of inspection areas. For each of the divided inspection areas, detection means for detecting a foreign matter defect or pattern defect based on a reference corresponding to the inspection area, and information of the foreign matter defect or pattern defect detected by the detection means for each inspection area are used. Processing means for obtaining information on the occurrence frequency of the foreign matter defect or pattern defect for each inspection area, and information on the occurrence frequency of the foreign matter defect or pattern defect for each inspection area obtained by the processing means Defect inspection apparatus characterized by comprising a display unit that. 6. The display means distinguishes and displays information of a foreign matter defect or pattern defect of a specific size for each inspection area from information of foreign matter defects or pattern defects of other sizes. The defect inspection apparatus according to claim 5. 7. The defect inspection apparatus according to claim 5, wherein the display means displays a frequency distribution of the size of the foreign matter defect or the pattern defect for each area. 8. An apparatus for detecting foreign matter defects and pattern defects of an object to be inspected, comprising: illumination means for irradiating the object to be inspected with light; and the object to be inspected by irradiation of light by the illumination means. Of the reflected light or the scattered light, and a signal obtained by detecting at least one of the reflected light or the scattered light by the light detecting means is processed to detect a foreign matter defect or a pattern defect. Detection means for detecting at least any one, processing means for classifying at least one of the foreign matter defect and the pattern defect detected by the detection means for each type of the defect, and each type of the defect classified by the processing means And a display unit for displaying information on the frequency of occurrence of defects. 9. The processing means classifies information on the frequency of defect occurrence for each type of defect classified by the processing means by size of the defect and obtains the frequency of occurrence of defects for each size. 9. The defect inspection apparatus according to claim 8, wherein the display unit displays information regarding a frequency of occurrence of defects for each of the obtained classifications. 10. The defect inspection apparatus according to claim 8, wherein the display unit displays information regarding the distribution of the defect occurrence on the inspection target object by classifying the information for each defect type. . 11. A method for detecting a foreign matter defect or a pattern defect of an object to be inspected, which comprises irradiating light to the object to be inspected, and reflecting light or scattered light from the object to be inspected by the irradiation of the light. Is detected, the signal obtained by detecting the reflected light or scattered light is processed to detect a foreign matter defect or a pattern defect, and the information of the detected foreign matter defect or pattern defect is used to detect the foreign matter defect or the pattern defect. It is characterized in that the size is obtained and the frequency of the obtained size of the foreign matter defect or pattern defect is obtained, and the information of the obtained size of the foreign matter defect or pattern defect and the occurrence frequency for each size is output. Defect inspection method. 12. The defect inspection method according to claim 11, wherein information on a cause of failure is displayed on a screen in association with information on the size of the foreign matter defect or the pattern defect. 13. Among the particle defects or pattern defects, information of particle size defects or pattern defects of a specific size is distinguished from information of particle size defects or pattern defects of other sizes and displayed on the screen. The defect inspection method according to claim 11, which is characterized in that. 14. The yield of the foreign matter defect or the pattern defect is influenced by using the information of good / defective obtained by the electrical inspection of the inspection object and the information of the size of the defect obtained by the processing means. 12. The defect inspection method according to claim 11, wherein the degree is calculated, and the result of the degree of influence on the calculated yield is displayed on the screen. 15. A method for detecting a foreign matter defect or a pattern defect of an object to be inspected, which comprises irradiating light to the object to be inspected, and reflecting light or scattered light from the object to be inspected by the irradiation of the light. Based on a reference corresponding to the inspection region, the signal obtained by detecting the reflected light or scattered light for each of the divided inspection regions by dividing the inspection object into a plurality of inspection regions. The foreign matter defect or pattern defect is detected by processing, and the information of the occurrence frequency of the foreign matter defect or pattern defect for each inspection area is obtained by using the information of the foreign matter defect or pattern defect detected for each inspection area. A defect inspection method, wherein information on the frequency of occurrence of the foreign matter defect or pattern defect for each inspection region is displayed. 16. The information of a foreign particle defect or pattern defect of a specific size is displayed for each of the inspection areas in distinction from the information of foreign particle defects or pattern defects of other sizes. Defect inspection method. 17. The defect inspection method according to claim 15, wherein a frequency distribution of the size of the foreign matter defect or the pattern defect is displayed for each area on the screen. 18. A method for detecting a foreign matter defect or a pattern defect of an object to be inspected, which comprises irradiating light to the object to be inspected, and reflecting light or scattered light from the object to be inspected by the irradiation of the light. Of the reflected light or scattered light, the signal obtained by detecting at least one of the reflected light and the scattered light is processed to detect at least one of a foreign matter defect or a pattern defect, and the detected foreign matter defect or pattern defect. The defect inspection method, wherein at least one of the defects is classified according to the kind of the defect, and information regarding the frequency of occurrence of the defect for each classified kind of the defect is displayed. 19. The information on the frequency of occurrence of defects for each of the classified types of defects is classified for each size of the defects, the frequency of occurrence of defects for each size is obtained, and the defect for each of the obtained classifications is obtained. 19. The defect inspection method according to claim 18, wherein information on the frequency of occurrence is displayed on the screen. 20. The defect inspection method according to claim 18, wherein the information on the distribution of the defect occurrences on the inspection object is classified for each defect type and displayed on the screen.