WO2022009392A1

WO2022009392A1 - Defect inspection device and defect inspection method

Info

Publication number: WO2022009392A1
Application number: PCT/JP2020/026882
Authority: WO
Inventors: 友貴入
Original assignee: 株式会社日立ハイテク
Priority date: 2020-07-09
Filing date: 2020-07-09
Publication date: 2022-01-13

Abstract

An object of the present disclosure is to provide a defect inspection device that can improve defect coordinate accuracy by correcting defect coordinates according to change over time during a wafer operation. The defect inspection device according to the present disclosure acquires, for a detection signal obtained from a first region on a calibration sample, the position of the object at each first distance in the first region, and acquires, for the detection signal obtained from a second region different from the first region on the calibration sample, the position of the object at each second distance in the second region, the second distance being different from the first distance (See FIG. 5).

Description

Defect inspection equipment, defect inspection method

The present disclosure relates to a defect inspection device that inspects a defect of a sample by irradiating the sample with light.

In the semiconductor manufacturing process, sample defects (scratches, foreign substances, etc.) have a large effect on the yield, and feeding back the defect inspection information from the defect inspection device to the semiconductor manufacturing process and the manufacturing device is the yield management. is important. The coordinate accuracy of the defect detected by the optical defect inspection device is important when identifying the defect portion, for example, in the semiconductor manufacturing process. Defect coordinate accuracy is also important when observing defects with a review device, classifying defects, and determining pass / fail. In recent years, with the miniaturization of semiconductors, the demand for defect coordinate accuracy has been increasing year by year.

Patent Document 1 describes a technique for reducing errors in detected defect coordinates. In the same document, a sample wafer for coordinate calibration in which a defect whose coordinates are known in advance is formed is irradiated with illumination light, scattered light from the sample wafer is detected, and the image coordinates of the defect on the surface are corrected. Based on the corrected image coordinates, defects on the surface of the object to be inspected are corrected. On the sample wafer for coordinate calibration, defects created at known positions are arranged at equal intervals in a grid pattern.

Japanese Unexamined Patent Publication No. 2011-075431

In the optical defect inspection device, improvement of defect coordinate accuracy is required. However, in the conventional coordinate correction, (a) the deflection of the wafer itself caused by the rotation of the stage, (b) the difference in the holding method such as how to place the wafer on the stage, (c) the difference in the rotation speed of the stage during inspection, and the laser. Sufficient consideration was not given to the difference in operating conditions such as the strength of the wafer. If the defect coordinates are not detected in consideration of these changes over time, there is a possibility that a discrepancy may occur between the actual defect position and the defect position recognized by the inspection device, which leads to an increase in observation time in the review device.

This disclosure has been made in view of the above-mentioned problems, and is a defect inspection capable of improving the defect coordinate accuracy by correcting the defect coordinates according to the wafer holding method and the change with time that occurs during operation. The purpose is to provide the device.

The defect inspection apparatus according to the present disclosure acquires the position of the object for each first distance in the first region for the detection signal obtained from the first region on the calibration sample, and obtains the position of the object on the calibration sample. For the detection signal obtained from the second region different from the first region, the position of the object is acquired for each second distance different from the first distance in the second region.

According to the defect inspection device according to the present disclosure, the defect coordinate accuracy can be improved. Further, by improving the defect coordinate accuracy, it is expected that the coordinate matching accuracy between the defect inspection device and the defect review device will be improved, and the time of the observation process by the defect review device will be shortened.

It is an overall schematic diagram of the defect inspection apparatus 100 which concerns on Embodiment 1. FIG. It is a figure which shows the flow of the defect inspection in this disclosure. It is a figure which shows the example which the surface of the calibration sample in Embodiment 1 was divided into regions. It is a figure which shows the example which formed the defect on the calibration sample. It is a figure which shows the example of the case where the sample stage 21 is fixed to the central portion of a wafer by back surface adsorption or the like in the region division of the calibration sample in Embodiment 1. FIG. It is a figure which shows the example of the case where the grid size is set according to the operating state of the stage apparatus 20 in the region division of the calibration sample in Embodiment 1. FIG. It is a figure which shows the example of the case where the sample stage 21 fixes substantially the entire surface of the wafer in the region division of the calibration sample in the first embodiment. It is a figure which shows the example of the case where the sample stage 21 fixes only the end portion of a wafer in the region division of the calibration sample in Embodiment 1. FIG. It is a flowchart explaining the procedure which the defect inspection apparatus 100 in Embodiment 1 corrects the coordinate deviation between the apparatus. It is a figure explaining the specific example of the procedure of correcting a defect coordinate in S106. FIG. 5 is a flowchart illustrating a procedure in which the defect inspection device 100 according to the second embodiment diagnoses a sign of abnormality in the device. An example of each map is shown.

<Embodiment 1>
FIG. 1 is an overall schematic view of the defect inspection device 100 according to the first embodiment of the present disclosure. The defect inspection device 100 inspects the defect of the sample 1 by irradiating the sample 1 moving while rotating with illumination light L1 (L1a and L1b) and scanning the sample 1 spirally or concentrically. Defect inspection system. As the sample 1, for example, a disk-shaped wafer (including a wafer at each stage of the semiconductor manufacturing process such as a bare wafer, a wafer with a film, a wafer with a bump, and a wafer with a pattern) is assumed. The defects detected by the defect inspection device 100 are scratches and waviness of the sample 1, foreign matter adhering to the sample 1, and the like.

The defect inspection device 100 includes a stage device 20, a lighting detection unit 24, a signal processing unit 16, a storage area unit 17, a sign diagnosis unit 18, a controller 19, and a stage control unit 23.

The stage device 20 includes a sample stage 21 and an XZθ stage. The XZθ stage has a rotary stage, a straight X stage, and a height direction Z stage. The sample stage 21 is an inspection table that holds the sample 1 horizontally. The sample stage 21 may be a type that holds the sample 1 by adsorbing to the back surface of the sample 1, or a type that holds the sample 1 by fixing only the end of the sample 1 at some points. Scales and encoders that show the position coordinates are placed on each stage. The detected position coordinates (R, θ) are output to the controller 19. The sensor 25 detects the height of the sample 1 and outputs it to the controller 19. As the sensor 25, a non-contact displacement sensor such as an optical type or an eddy current type can be used. The size of the warp of the sample 1 can also be measured by the sensor 25.

The illumination detection unit 24 includes an irradiation optical system and a detection optical system. The irradiation optical system irradiates the sample 1 with the illumination light L1. The illumination optical system includes a light source 10, mirrors 11a to 11c,

irradiation lenses

12 and 26, and an optical element correction mechanism 27. The detection optical system detects the inspection light L2 scattered or reflected in the sample 1. The detection optical system includes a condenser lens 13, a detector 14, and a detection circuit 15. The mirror 11c switches between irradiating the illumination light from the vertical direction (L1b) and irradiating it from diagonally above (L1a). The

mirrors

11a and 11b adjust the course of the irradiation light L1 so as to irradiate the irradiation light from diagonally above. The optical element correction mechanism 27 monitors and corrects the optical axis of the irradiation optical system.

In FIG. 1, the lights L1a and L1b emitted from the light source 10 are applied to the sample 1 via the mirrors 11a to 11c and the

irradiation lenses

12 and 26. When the sample 1 is rotated and moved by the stage device 20, the irradiation light L1 is irradiated in a spiral trajectory from the center of the sample 1 to the outer edge, whereby the entire surface of the sample 1 is inspected. The detection result of the inspection light L2 from the sample 1 is output to the signal processing unit 16 via the condenser lens 13, the detector 14, and the detection circuit 15. The irradiation light may be a locus from the outer edge of the sample 1 toward the center.

The signal processing unit 16 generates an inspection result from the detection result by the illumination detection unit 24 and the Rθ coordinates input from the controller 19. The inspection results include the position, size, shape, etc. of defects (foreign matter, scratches, etc.). The signal processing unit 16 calculates a correction value from the inspection results for each operation and operating state of the wafer stored in the storage area unit 17. The signal processing unit 16 corrects the detection coordinates of the inspection result by using the correction value, thereby improving the defect detection coordinate accuracy.

The storage area unit 17 stores the inspection result and the correction value generated by the signal processing unit 16, and also stores the deviation amount of the defect coordinates. By storing these for each wafer holding method and operating state, the same correction value can be used when the inspection is performed under the same conditions.

The sign diagnosis unit 18 detects a sign of an abnormality by monitoring a change in the amount of deviation using the inspection result and the amount of deviation stored in the storage area unit 17, the detection result by each sensor, and the like. The details of the predictive diagnosis unit 18 will be described in the second embodiment.

The stage control unit 23 controls the operation of the stage device 20. For example, the stage device 20 can be controlled by controlling a motor driver that drives the drive device of the straight-ahead X stage, a motor driver that drives the drive device of the rotary stage, and the like. When a command value for the operation of the stage device 20 is input from the controller 19, the stage control unit 23 drives the drive device in response to the command, whereby the stage device 20 operates.

FIG. 2 is a diagram showing the flow of defect inspection in the present disclosure. For example, the FIB device 42 creates a built-in defect on the sample 1. The method of forming the built-in defect is not limited to the method using the FIB device 42. The review device 41 reviews the built-in defect, and the defect inspection device 100 inspects the built-in defect. By matching the defect coordinates in the review device 41 with the defect coordinates in the defect inspection device 100, the correction value of the defect coordinates can be calculated. The defect coordinates detected by the defect inspection device 100 can also be reviewed by the review device 41.

In order to carry out defect inspection in this way, it is necessary to carry out inspection across each device and confirm the defect position. Therefore, if the number of built-in defects is large, the inspection time in the defect inspection device 100 and the review time in the review device 41 become excessive. In order to shorten the time of the entire defect inspection, it is necessary to efficiently form built-in defects, change the sampling interval, and acquire necessary and sufficient data.

FIG. 3 is a diagram showing an example in which the surface of the calibration sample in the first embodiment is divided into regions. In the example of FIG. 3, the grid regions are all equal in size and the grid is square. The size and shape of the grid region can be arbitrarily specified. Since the data processing time depends on the number of grids, it is desirable to set the number of grids to the minimum necessary.

FIG. 4 is a diagram showing an example in which a defect is formed on a calibration sample. The coordinates of the grid points are known. The built-in defect 30 is arranged on the grid point. The built-in defect 30 has a shape, size, and position that can be detected by scattered light. It is desirable to arbitrarily set the size and shape of the built-in defect 30 according to the purpose of use. The built-in defect 30 can be made by using, for example, a focused ion beam (FIB) device or photolithography. The defect inspection device 100 corrects the defect coordinates by using the calibration sample.

The grid size and arrangement of the grid points formed on the calibration sample may be changed between the region where the defect coordinates are likely to be displaced between the devices and the other region. Factors that cause defect coordinate deviation include (a) deflection of the wafer itself caused by the rotation of the stage, (b) differences in wafer holding methods such as how to place the wafer on the stage, and (c) difference in the rotation speed of the stage during inspection. , Differences in operating conditions such as laser strength, etc. In changing the region division of the calibration sample, the shape, size, and position of the built-in defect 30 may be arbitrarily arranged.

The arrangement interval of the built-in defects 30 may be changed for each area. Alternatively, as shown in FIG. 4, the built-in defects 30 are evenly arranged in the entire region in advance, and the distance interval between the grid points when the defect inspection device 100 detects the built-in defects 30 is changed for each region. The grid size and arrangement may be virtually changed for each area. As a method of changing the processing interval for detecting the built-in defect 30, the user may specify the coordinates of each area via the GUI (Graphical User Interface). For example, the following three patterns can be considered.

First: The user specifies the first area on the calibration sample, and the other area on the calibration sample is the second area. Second: The user specifies the first region and the second region (or the grid size of each region) individually on the calibration sample. Third: After inspecting all the built-in defects 30, the user specifies the first region and the second region on the calibration sample. In the first and second methods, the built-in defects 30 to be inspected in advance can be narrowed down, so that the inspection time can be shortened. In the third method, although all points are inspected, the points for calculating the correction value can be narrowed down, and the calculation processing time can be shortened. As a result, the inspection time can be shortened.

FIG. 5 is a diagram showing an example in which the sample stage 21 is fixed to the central portion of the wafer by back surface adsorption or the like in the region division of the calibration sample in the first embodiment. Since the inspection of the sample 1 is carried out while the stage device 20 is rotating, the outer edge portion of the sample 1 is more likely to have coordinate deviation than the fixed central portion. The unfixed portion also causes warpage due to the wafer itself. Therefore, the fixed portion is defined as the first region, the non-fixed portion is defined as the second region, and the grid size of the first region is larger than the grid size of the second region. The first region can be arbitrarily set according to the size of the central portion of the sample stage 21.

FIG. 6 is a diagram showing an example in which the grid size is set according to the operating state of the stage device 20 in the region division of the calibration sample in the first embodiment. The stage device 20 also moves straight while rotating in the θ direction. The second region is a region where the Rθ velocity becomes irregular due to the acceleration / deceleration of the stage device 20. The more variable the Rθ speed is, the more mechanical vibration or the like applied to the stage can be changed, and irregular coordinate deviations can occur. The first region is a region where acceleration / deceleration is smaller than that of the second region (ideally, there is no acceleration / deceleration). In the region where acceleration / deceleration is small, the coordinate deviation between the devices is considered to be small, so that the grid size can be increased.

The difference in the rotation speed on the surface area of the calibration sample also causes the difference in the laser intensity applied to the calibration sample. Therefore, it can be said that the calibration sample of FIG. 6 takes into consideration the difference in laser intensity caused by the difference in rotation speed in addition to the difference in rotation speed.

FIG. 7 is a diagram showing an example in which the sample stage 21 fixes substantially the entire surface of the wafer in the region division of the calibration sample in the first embodiment. Since there are many fixed regions as compared with FIG. 5, the first region is made wider than that of FIG. 5, and the second region is made narrower than that of FIG.

FIG. 8 is a diagram showing an example in which the sample stage 21 fixes only the end portion (edge) of the wafer in the region division of the calibration sample in the first embodiment. When only the end portion is fixed, the wafer tends to bend and the coordinate shift easily occurs in the fixed portion. This is because a force acts between the fixing member and the wafer. Therefore, the grid size is large with most of the wafer including the central portion as the first region, and the grid size is small with the end portion fixing the wafer and the sample stage 21 as the second region.

FIG. 9 is a flowchart illustrating a procedure in which the defect inspection device 100 in the first embodiment corrects a coordinate deviation between the devices. Each step of FIG. 9 will be described below.

(FIG. 9: Steps S100 to S101)
If the first region and the second region on the calibration sample have already been set, proceed to S102 (S100: Yes), and if not set, for example, the user sets each region on the GUI (S100: No, S101).

(FIG. 9: Steps S102 to S104)
The defect inspection device 100 inspects (actually measures) the coordinates of the grid points (built-in defects 30) on the calibration sample (S102). As a result, the measured coordinates of the grid points on the calibration sample can be obtained (S103). The signal processing unit 16 compares the actually measured coordinates of the built-in defect 30 with the known coordinates, and calculates the amount of deviation between the two (S104). This deviation amount represents the deviation amount between the known value and the measured value of the grid points on the calibration sample, but it is also the defect deviation amount when the defect is actually measured.

(FIG. 9: Step S105)
The signal processing unit 16 calculates a correction value for correcting the coordinate deviation according to the correlation between the defect deviation amount and each parameter. Each parameter referred to here is a value obtained from each sensor included in the defect inspection device 100, such as an eccentric amount of the calibration sample, a rotation deviation amount of the calibration sample, an optical axis deviation amount, and the like. The amount of eccentricity and the amount of rotational deviation of the calibration sample can be obtained from the sensor that detects the amount of movement of the stage. The amount of optical axis deviation can be obtained from the optical element correction mechanism 27.

(FIG. 9: Step S105: Supplement)
It is considered that the factor that causes the amount of defect deviation appears at least indirectly in the value detected by each sensor. Therefore, there is a correlation between the amount of defect deviation / each parameter / correction value. By acquiring this correlation in advance and applying the defect deviation amount obtained by actual measurement and each parameter to the correlation, a correction value corresponding to these can be obtained. This step is to do this.

(FIG. 9: step S106)
The signal processing unit 16 corrects the defect coordinates by using the correction value acquired in S105. Specifically, the correction amount can be determined by the weighted average as shown in FIG. 10 described later, using the distances from the four known grid points around the actually measured defect to the defect. Instead of the weighted average, the correction amount may be determined by an appropriate function such as a spline function.

FIG. 10 is a diagram illustrating a specific example of the procedure for correcting the defect coordinates in S106. The defect 54 is a defect detected in the inspection process. The grid points 50 to 53 are actually measured grid points. In S105, the correction value between the known grid points and the grid points 50 to 53 is calculated in advance. In FIG. 10, the correction value is also shown for each grid point. For example, the correction value between the grid point 50 and the corresponding known grid point is (x, y).

In S106, the distance between the defect 54 and each of the grid points 50 to 53 is obtained, and the correction value weighting is determined. The weighting range is 0 <= dx <= 1 and 0 <= dy <= 1. The weighted average of the correction values of the grid points 50 to 53 is used as the correction value of the defect 54. The correction value using the weighted average is (x, y) * (1-dx) * (1-dy) + (x, y + 1) * (1-dx) * dy + (x + 1, y) * dx * (1). It can be calculated by −dy) + (x + 1, y + 1) * dx * dy.

<Embodiment 1: Summary>
The defect inspection device 100 according to the first embodiment divides the surface region of the calibration sample into a second region where the amount of defect deviation is desired to be strictly detected and a first region where the defect deviation amount does not need to be strictly detected, and is a second region. In, the built-in defect 30 is detected at intervals shorter than the first region. This makes it possible to accurately detect the coordinate deviation caused by the change with time such as the wafer state in the second region.

In the first embodiment, the built-in defects 30 on the calibration sample may be arranged on different grid sizes in the first region and the second region, and the grid sizes are the same in the first region and the second region. While setting, the distance interval for detecting the built-in defect 30 by the signal processing unit 16 may be changed in the arithmetic processing. In the former case, the processing of the signal processing unit 16 can be simplified. In the latter case, the calibration sample can be manufactured more easily than the former.

The defect inspection device 100 according to the first embodiment determines a correction value for correcting the coordinate deviation according to the correlation between the parameter detected by each sensor included in the defect inspection device 100 and the defect deviation amount. .. This is based on the fact that the cause of the coordinate deviation is considered to appear in the detection parameters. By this method, the correction value can be appropriately determined according to the operating state of the defect inspection device 100 (including the wafer) at that time. That is, it is possible to determine an appropriate correction value for the change over time in the operating state of the defect inspection device 100.

<Embodiment 2>
FIG. 11 is a flowchart illustrating a procedure in which the defect inspection device 100 according to the second embodiment of the present disclosure diagnoses a sign of abnormality in the device. This flowchart is carried out by the predictive diagnosis unit 18. The configuration of the defect inspection device 100 is the same as that of the first embodiment. Each step of FIG. 11 will be described below.

(FIG. 11: Step S200)
The predictive diagnosis unit 18 acquires a wafer holding method and a defect deviation amount for each operating state from the storage area unit 17. The deviation amount is acquired in advance by the defect inspection device 100 measuring the calibration sample.

(FIG. 11: Step S201)
The predictive diagnosis unit 18 acquires the amount of deviation of each parameter from the storage area unit 17. The parameters referred to here are the same as the parameters in S105. That is, it is a parameter representing the state of each part of the defect inspection device 100 detected by each sensor included in the defect inspection device 100.

(FIG. 11: Step S202)
The predictive diagnosis unit 18 creates a deviation amount map showing the change with time of the deviation amount. For example, the first map represents the amount of deviation at time 1, and the second map represents the amount of deviation at time 2. A deviation amount map may be created for each grid point, or one map showing the deviation amount of all grid points may be created. The latter is assumed in FIG. 12, which will be described later. The predictive diagnosis unit 18 also creates a parameter map showing the change over time of the parameters for each parameter.

(FIG. 11: Step S203)
The predictive diagnosis unit 18 predicts the n + 1th shift amount map based on the change with time from the first to the nth slip amount map. For example, the n + 1th sheet can be predicted by using a moving average method or the like. The predictive diagnosis unit 18 also predicts the n + 1th sheet for each parameter map.

(FIG. 11: Steps S204 to S207)
The predictive diagnosis unit 18 is n + 1 when the deviation amount map of the n + 1th sheet exceeds the threshold value (S204: Yes) and any of the parameter maps of the n + 1th sheet exceeds the threshold value (S205: Yes). It is determined that an abnormality of the defect inspection device 100 may occur at the time corresponding to the first sheet (S206). The predictive diagnosis unit 18 outputs the determination result as a predictive diagnosis result (S207). The output format may be any format such as screen display and data output.

(FIG. 11: Steps S204 to S205: Supplement)
As for the threshold value, the upper limit or the lower limit can be arbitrarily determined in advance. If it deviates from the upper and lower thresholds, that is, if it deviates from the predetermined normal range, it is diagnosed that there is an abnormality sign, and if it is within the upper and lower thresholds, there is no abnormality sign.

FIG. 12 shows an example of each map. In FIG. 12, the n + 1th sheet of the deviation amount map 500 exceeds the threshold value. The n + 1th sheet of the eccentricity map 502 does not exceed the threshold value, but the n + 1th sheet of the optical axis deviation amount map 501 also exceeds the threshold value, so that it is determined to be abnormal. The parameter map can be increased according to the number of parameters stored in the storage area portion 17. The parameters can be increased by installing the corresponding sensor in the defect inspection device 100. For example, an optical axis sensor or a beam stabilizer may be provided to see the amount of laser shake, an acceleration sensor may be provided to measure the vibration of the stage, and a linear scale may be provided to measure the position of the stage.

The predictive diagnosis unit 18 feeds back the predictive diagnosis result to the defect inspection device 100. This will reduce the amount of deviation. For example, by monitoring the optical axis deviation with the optical element correction mechanism 27, the optical axis deviation can be corrected. The stage device 20 includes a sensor for detecting the outer circumference of the wafer and an encoder in the θ direction, whereby the amount of eccentricity of the wafer can be detected and corrected.

These monitors and sensors are used for correction during inspection, but there is a risk that errors will occur in the output results due to temperature drift of the monitors and sensors themselves. Therefore, when it is determined in the sign diagnosis that there is an abnormality sign, the offset amount may be obtained from the error of the sensor itself, and the defect inspection may be performed including the offset at the time of inspection. Thereby, the defect position coordinate accuracy at the time of defect detection can be improved. That is, the predictive diagnosis result of FIG. 12 has the significance of predicting the causal parameter that causes the abnormality in the n + 1th sheet, in addition to predicting the abnormality of the defect inspection device 100.

Similarly, if the deviation amount and the parameter exceed the threshold value before the nth sheet, the predictive diagnosis unit 18 estimates that the defect inspection device 100 is abnormal at that time and the cause parameter causing the abnormality. can do.

<About a modified example of this disclosure>
The present disclosure is not limited to the embodiments described above, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present disclosure in an easy-to-understand manner, and is not necessarily limited to the one including all the configurations described. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

In the above embodiment, the example in which the grid points are formed in a regular square shape is shown, but the grid shape is not limited to this. The grid shape is arbitrary as long as the difference between the coordinates of the built-in defect 30 at the known grid points on the calibration sample and the coordinates of the built-in defect 30 obtained by actually measuring the calibration sample is corrected.

In the above embodiment, it has been described that the first region and the second region are set on the calibration sample, but the third and subsequent regions may also be set. Even when the third and subsequent regions are set, the grid sizes of the regions are different from each other.

In the above embodiments, the sample (or calibration sample, the same applies hereinafter) can be inspected by irradiating the sample with light and detecting reflected or scattered light from the sample. The present disclosure may be applied in any case.

In the above embodiment, the signal processing unit 16, the predictive diagnosis unit 18, the controller 19, and the stage control unit 23 can be configured by hardware such as a circuit device that implements these functions, and these functions can be provided. It can also be configured by executing the implemented software by an arithmetic unit.

10: Light source 14: Detector 16: Signal processing unit 20: Stage device 21: Sample stage 25: Sensor 100: Defect inspection device

Claims

A defect inspection device that inspects defects in a sample by irradiating the sample with light.
A stage that holds the sample,
A light source that irradiates the sample with light,
A detector that detects the light scattered or reflected from the sample,
A signal processing unit that inspects the defect using a detection signal representing the result of the detector detecting the light.
Equipped with
The signal processing unit is configured to correct the coordinates of the defect by using the detection signal representing the result of the detector detecting the light obtained from the calibration sample in which the object is formed on the grid point. And
The signal processing unit acquires the position of the object for each first distance in the first region for the detection signal obtained from the first region on the calibration sample.
For the detection signal obtained from the second region different from the first region on the calibration sample, the signal processing unit may use the object for each second distance different from the first distance in the second region. Defect inspection device characterized by acquiring the position of.
Claim 1 is characterized in that the first region is arranged at a position where the deviation amount in which the result of detecting the coordinates of the object deviates from the actual coordinates of the object is smaller than that of the second region. The defect inspection device described.
The first region is
Deflection of the calibration sample caused by the rotation of the stage,
The position of the fixing point where the calibration sample is fixed to the stage,
The difference in rotation speed on the calibration sample when the stage rotates,
The defect inspection apparatus according to claim 2, wherein the deviation amount caused by at least one of the two is arranged at a position smaller than that of the second region.
The first region is arranged in the center of the surface of the calibration sample and the peripheral region thereof.
The defect inspection apparatus according to claim 2, wherein the second region is a region of the surface of the calibration sample excluding the first region.
The first region is arranged so as to surround the center of the surface of the calibration sample.
The defect inspection apparatus according to claim 2, wherein the second region is a region of the surface of the calibration sample surrounded by the first region and a region outside the first region.
The second region is a peripheral region where the calibration sample is fixed to the stage.
The defect inspection apparatus according to claim 2, wherein the first region is a region of the surface of the calibration sample excluding the second region.
The defect inspection apparatus according to claim 2, wherein the first distance is larger than the second distance.
In the first region, the signal processing unit acquires the position of the object for each first distance by setting the interval between the grid points on the calibration sample to the first distance.
The signal processing unit is characterized in that, in the second region, the position of the object is acquired for each second distance by setting the interval between the grid points on the calibration sample to the second distance. 2. The defect inspection device according to claim 2.
In the first region, the object is formed for each first distance.
The defect inspection apparatus according to claim 1, wherein in the second region, the object is formed for each second distance.
The signal processing unit acquires the amount of deviation in which the result of detecting the coordinates of the object deviates from the actual coordinates of the object.
The defect inspection device further includes a sensor for detecting a parameter causing the deviation amount.
The defect inspection device according to claim 1, wherein the signal processing unit corrects the coordinates of the defect according to the correlation between the deviation amount and the parameter.
The signal processing unit weights and adds the correction value corresponding to each grid point according to the difference between the coordinates of the defect and the coordinates of each of the four grid points surrounding the defect, thereby causing the defect. The defect inspection apparatus according to claim 1, wherein a correction value for correcting the coordinates is calculated.
The defect inspection device further determines whether or not the deviation amount may exceed the threshold value according to the time course of the deviation amount in which the result of detecting the coordinates of the object deviates from the actual coordinates of the object. The defect inspection device according to claim 1, further comprising a predictive diagnostic unit.
The defect inspection device further includes a sensor for detecting a parameter causing the deviation amount.
The predictive diagnosis unit creates a deviation amount map describing the change with time of the deviation amount and a parameter map describing the change with time of the parameter.
The predictive diagnosis unit determines whether or not the deviation amount may exceed the threshold value according to the deviation amount map, and determines whether or not the deviation amount may exceed the threshold value.
The predictive diagnosis unit determines whether or not the parameter may exceed the threshold value according to the parameter map, and determines whether or not the parameter may exceed the threshold value.
The claim is characterized in that the predictive diagnosis unit notifies that the defect inspection device is abnormal when the deviation amount may exceed the threshold value and the parameter may exceed the threshold value. 12. The defect inspection device according to 12.
When the deviation amount described by the deviation amount map exceeds the threshold value and the parameter described by the parameter map exceeds the threshold value, the predictive diagnostic unit has the deviation amount. 13. The defect inspection apparatus according to claim 13, wherein an estimation result indicating that the cause of the above is the parameter is output.
It is a defect inspection method for inspecting a defect of the sample by irradiating the sample with light.
The step of irradiating the sample with light,
The step of detecting the light scattered or reflected from the sample,
A step of inspecting the defect using a detection signal representing the result of detecting the light in the detection step.
Have,
In the step of inspecting the defect, the coordinates of the defect are corrected by using the detection signal representing the detection result in the step of detecting the light reflected from the calibration sample in which the object is formed on the grid point. ,
In the step of inspecting the defect, for the detection signal obtained from the first region on the calibration sample, the position of the object is acquired for each first distance in the first region.
In the step of inspecting the defect, the detection signal obtained from the second region different from the first region on the calibration sample is obtained for each second distance different from the first distance in the second region. A defect inspection method characterized by acquiring the position of the object.