JP4761574B2 - Inspection apparatus, correction method, inspection method, and pattern substrate manufacturing method - Google Patents

Description

  The present invention relates to an inspection apparatus, a correction method, an inspection method, and a pattern substrate manufacturing method, and in particular, an inspection apparatus having an image sensor that outputs an output signal from a plurality of pixels divided into a plurality of channels and each channel of the image sensor The present invention relates to a correction method for correcting an output signal from a laser beam, an inspection method using the same, and a pattern substrate manufacturing method.

  In order to increase the image processing speed, a CCD image sensor that divides and outputs charges accumulated in a plurality of pixels into a plurality of channels is widely used. In such a multi-channel drive type CCD image sensor, there is a problem that a level difference of an output signal occurs between channels due to variations in characteristics of each output channel.

  Therefore, a method for correcting a level difference existing between the channels of the CCD image sensor has been proposed (see, for example, Patent Documents 1 and 2). In the image reading apparatus described in Patent Document 1, a plurality of continuous pixels equal to the number of channels of the CCD image sensor are sequentially selected, and averaging processing or smoothing processing is performed. The level difference between channels due to variation is reduced.

Further, in the image reading apparatus described in Patent Document 2, a shift register that transfers charges accumulated in a pixel includes a CCD image sensor that outputs a divided part from a central part to a first half part and a second half part. The image data level in the vicinity of the joint of the rear application part is detected for each output direction, and linearity correction is performed to correct the linearity of the seam between the first half part and the second half part.
JP-A-11-275321 JP 2007-49673 A

  By the way, in defect inspection apparatuses such as a semiconductor inspection apparatus, an LCD inspection apparatus, and a mask inspection apparatus, inspection of defects and the like is performed by monitoring the substrate using a CCD image sensor. In these defect inspection apparatuses, a multi-channel drive type CCD image sensor as described above is used. Further, in order to inspect the entire surface of the substrate, the inspection is performed by accurately moving the CCD image sensor and the substrate to be inspected. In order to improve manufacturing yield and the like, a defect inspection apparatus that detects surface defects such as semiconductor wafers, mask blanks, and photomasks is required to perform inspection with higher sensitivity.

  As shown in FIG. 8, in the multi-channel drive type CCD image sensor, in addition to the sensitivity variation of each pixel, the linearity error of the first pixel of the joint of each channel (the first pixel of the joint of each channel and the pixels near the center) Sensitivity difference). When gain correction / offset correction is performed by setting a single gain for a single input, the output signal from each pixel for the single input can be made constant (FIG. 9). ). However, at the time of gray tone input, as shown in FIG. 10, due to the influence of the linearity error, insufficient gain or over gain occurs at the first pixel of the joint of each channel, and the output signal of the first pixel of the joint becomes the output signal of the other pixels. There is a case where a whisker signal protruding from the surface is generated.

  In a defect inspection apparatus for inspecting a repetitive pattern such as an LCD photomask, a pitch shift inspection (hereinafter referred to as a cell shift inspection) for comparing an image captured by a CCD image sensor with an image shifted by a repetitive pattern pitch is known. . In the cell shift inspection, a defect inspection is performed by comparing a difference signal (pitch shift difference signal (FIG. 11)) between a captured image and an image shifted by a repeated pattern pitch with a slice level. When a cell shift inspection is performed using the above-described multi-channel drive type CCD image sensor, a pseudo signal that is erroneously detected as a defect at the joint of each channel due to the influence of a beard signal even though there is no actual defect. Defects may occur.

  By setting the slice level high, it is possible to eliminate such a pseudo defect so as not to detect it, but there is a possibility that a true defect cannot be detected. Thus, there exists a problem that the detection sensitivity of a defect cannot be raised. The above-mentioned problems occur in the same manner also in the surface inspection of semiconductor wafers, mask blanks for manufacturing semiconductor devices, pattern inspection of photomasks, and the like.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an inspection apparatus, a correction method, an inspection method, and a pattern substrate manufacturing method that can suppress variations in sensitivity of each pixel. .

  An inspection apparatus according to a first aspect of the present invention is an inspection apparatus that inspects the sample by using an image sensor that receives light from the sample. The inspection apparatus is provided in the image sensor and corresponds to an incident light amount. Based on a relationship between a plurality of pixels that output an output signal, an output unit that divides and outputs the output signal output from the plurality of pixels into a plurality of channels, and an incident light amount and an output signal of each pixel A linearity correction unit that performs linearity correction of the output signal for each of the plurality of pixels in accordance with the set linearity correction data. As a result, it is possible to suppress the generation of a whisker signal generated at the joint of the channel, to prevent the occurrence of a pseudo defect and to improve the inspection sensitivity. In addition, the occurrence of pseudo defects due to sensitivity variations of each pixel can be suppressed.

  In the inspection apparatus according to the second aspect of the present invention, in the inspection apparatus described above, the linearity correction unit performs linearity correction so that the linearity of pixels on both sides of the seam of the channel substantially coincides. As a result, it is possible to suppress the generation of a whisker signal generated at the joint of the channel, to prevent the occurrence of a pseudo defect and to improve the inspection sensitivity.

  In the inspection apparatus according to a third aspect of the present invention, in the inspection apparatus described above, the linearity correction unit corrects linearity so that each linearity of the plurality of pixels matches a reference level. As a result, it is possible to prevent the occurrence of a pseudo defect due to the generation of the beard signal generated at the joint of the channel and the sensitivity variation of each pixel.

  The inspection apparatus according to a fourth aspect of the present invention is the inspection apparatus, wherein the linearity correction unit includes a lookup table in which the linearity correction data created for each of the plurality of pixels is set. . As described above, by providing the lookup table, it is possible to reduce the time required for calculation related to the correction of linearity.

  A correction method according to a fifth aspect of the present invention is a correction method for correcting the linearity of an output signal of an image sensor that divides output signals from a plurality of pixels into a plurality of channels, and outputs the first light amount and Irradiating a second amount of light to set gains and offsets of the plurality of pixels; irradiating a light amount between the first amount of light and the second amount of light; and output signals of the plurality of pixels Creating linearity correction data for performing each linearity correction. Thereby, the sensitivity difference between each pixel can be suppressed.

  In the correction method according to the sixth aspect of the present invention, in the correction method described above, linearity correction data is created so that the linearity of the output signals of the pixels on both sides of the seam of the channel substantially match. Thereby, it is possible to suppress the generation of a beard signal at the joint of the channel.

  In the correction method according to the seventh aspect of the present invention, in the correction method described above, linearity correction data is created so that the linearity of each output signal of the plurality of pixels matches a reference level. Thereby, the sensitivity difference between each pixel can be suppressed.

  An inspection method according to an eighth aspect of the present invention includes a step of receiving light from an image sensor using the above correction method from a sample, and a step of detecting a defect based on an output signal whose linearity is corrected. Thereby, the sensitivity difference between each pixel can be suppressed and generation | occurrence | production of a pseudo defect can be suppressed.

  In the inspection method according to the ninth aspect of the present invention, the sample has a repetitive pattern, and the defect is detected by comparing the output signal in which the linearity is corrected and the output signal shifted by the repetitive pattern pitch. . The present invention is particularly effective in such a case.

  A pattern substrate manufacturing method according to a tenth aspect of the present invention includes a step of detecting a defect of the sample by the inspection method described above. Thereby, the manufacturing yield of the pattern substrate can be improved.

  According to the present invention, it is an object to provide an inspection apparatus, a correction method, an inspection method, and a pattern substrate manufacturing method that can suppress sensitivity variations among pixels.

  Embodiments of the present invention will be described below with reference to the drawings. The following description shows preferred embodiments of the present invention, and the scope of the present invention is not limited to the following embodiments. In the following description, the same reference numerals denote the same contents.

  An inspection apparatus according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a configuration of an inspection apparatus according to the present embodiment. In this embodiment, an inspection apparatus of a type that holds an object to be inspected vertically will be described. FIG. 2 is a diagram for explaining the configuration of an optical system used in the inspection apparatus shown in FIG. FIG. 3 is a diagram for explaining the configuration of the CCD linear sensor and the correction unit according to the present embodiment. Here, an inspection apparatus that inspects a photomask used in the manufacturing process of the liquid crystal display will be described as an example. In addition, the inspection apparatus according to the present embodiment is an inspection apparatus that inspects a repeated pattern formed at a predetermined pitch on a photomask.

  As shown in FIG. 1, the inspection apparatus according to the present embodiment includes a surface plate 1, a prism 2, a mask holder 3, a right angle stage 4 for a head, a CCD linear sensor 5, an air pad 6, a wire 7, a pulley 8, and a balance weight. 9, motor stage 10, vertical drive mechanism 11, horizontal drive mechanism 12, and the like. The inspection apparatus according to the present embodiment performs defect inspection by observing the surface state of the mask 13 with the CCD linear sensor 5.

  A rectangular parallelepiped prism 2 is attached on the surface plate 1, and a mask holder 3 is erected vertically on the side. This prism 2 is formed of granite in order to obtain a processing ease and flatness. Note that the prism 2 may be made of a material other than granite, such as metal or ceramic. A mask 13 to be inspected is attached to the mask holder 3. In order to hold the mask 13 vertically, the mounting angle between the mask 13 and the mask holder 3 can be adjusted. At the time of inspection, the mask 13 moves in the X direction.

  A right-angle stage 4 for the head is provided on two adjacent surfaces of the prism 2. A CCD linear sensor 5 is attached to the right-angle stage 4 for the head. An air pad 6 is provided between the right angle stage 4 for the head and the prism 2. A moving unit composed of the right-angle stage 4 for the head, the CCD linear sensor 5, the air pad 6, etc. moves up and down. That is, the CCD linear sensor 5 moves in the Y direction while being attached to the right angle stage 4 for the head.

  One end of a wire 7 is attached to the upper part of the right-angle stage 4 for the head. The wire 7 has a pulley 8 and a balance weight 9 attached to the other end. The balance weight 9 has a weight that can be balanced with moving parts such as the CCD linear sensor 5 and the right-angle stage 4 for the head. The head right-angle stage 4 is moved up and down by a motor stage 10 and a vertical drive mechanism 11 including a rack and pinion. In order to move in the vertical direction with good rectilinearity, the wire 7 is provided at the center of gravity of the moving part composed of the CCD linear sensor 5, the right angle stage 4 for the head, the air pad 6, and the like. This vertical movement control is performed by a control FA computer or the like provided outside, and the CCD linear sensor 5 can be moved to the inspection position of the mask 13. In addition, clean air is downflowing in the apparatus to suppress the generation of particles.

  The horizontal drive mechanism 12 moves the mask holder 3 to which the mask 13 is fixed in the X direction. The horizontal drive mechanism 12 includes a rail, a linear motor, and the like. The CCD linear sensor 5 is moved to a predetermined position by the vertical drive mechanism 11, and the mask holder 3 is moved at a constant speed in the X direction by the horizontal drive mechanism 12 while maintaining this state. As a result, the mask 13 is passed in front of the CCD linear sensor 5. Then, after moving the CCD linear sensor 5 in the vertical direction by a certain distance, the mask holder 3 is moved again in the X direction, and the surface condition of the mask 13 is inspected. By repeating this operation, the entire surface of the mask 13 can be inspected. The moving step in the vertical direction and the moving speed in the horizontal direction of the mask are adjusted according to the visual field range and performance of the CCD linear sensor 5.

  As shown in FIG. 2, the inspection apparatus according to the present embodiment is provided with a light source 14, a lens 15, a processing unit 16, and a correction unit 20. The light source 14 is, for example, a lamp light source, and emits illumination light in the direction of the mask 13. The mask 13 has a light shielding pattern 17 repeatedly formed on a transparent glass substrate at a predetermined pitch. That is, a portion other than the light shielding pattern 17 of the mask 13 is a transmission pattern. As described above, the mask 13 is fixed to the mask holder 3. The illumination light from the light source 14 passes through the mask holder 3 and enters the mask 13. Thereby, the mask 13 is illuminated uniformly from the back side. In the transmission pattern of the mask 13, most of the illumination light is transmitted. On the other hand, in the light shielding pattern 17 of the mask 13, most of the illumination light is shielded.

  The transmitted light that has passed through the mask 13 enters the lens 14. The transmitted light that has entered the lens 14 is refracted and enters the CCD linear sensor 5. The CCD linear sensor 5 has pixels arranged in a line for receiving light, and receives light from the surface of the mask 13. Here, the direction in which the pixels of the CCD linear sensor 5 are arranged is the Y direction, and the direction parallel to the sample surface and perpendicular to the Y direction is the X direction. The CCD linear sensor 5 outputs an output signal output according to the amount of incident light received by each pixel to the correction unit 20. The output signal of the CCD linear sensor 5 indicates the transmittance of the mask 13.

  The correction unit 20 performs linearity correction and gain correction of an output signal from each pixel of the CCD linear sensor 5. A method of correcting the output signal from each pixel will be described in detail later. The processing unit 16 performs arithmetic processing for detecting a defect on the mask 13 based on the output signal on which the linearity correction has been performed. Specifically, a pitch shift inspection (cell shift inspection) is performed in which an image captured by the CCD linear sensor 5 is compared with an image shifted by a repeated pattern pitch. In the cell shift inspection, a differential signal (pitch shift differential signal) between the captured image and an image shifted by the repeated pattern pitch is acquired. The processing unit 16 detects a defect by comparing a preset slice level with the pitch shift difference signal. In addition, the processing unit 16 specifies the position of the detected defect on the mask 13. That is, it is determined which position on the mask 13 corresponds to the timing at which the defect is detected, and the defect position on the mask 13 is stored. Thereby, the defect location on the mask 13 can be specified.

  As shown in FIG. 3, the CCD linear sensor 5 includes a plurality of pixels 51 that output an output signal corresponding to the amount of incident light, and an output unit 52 that transfers and outputs the output signals from the plurality of pixels 51. Yes. The plurality of pixels 51 accumulate electric charges corresponding to the amount of incident light by photoelectric conversion. In the output unit 52, charges accumulated in the plurality of pixels 51 are transferred by a shift register, and the charges transferred by the variable amplifier are converted into voltages. The CCD linear sensor 5 used in the present invention divides the output signals from the plurality of pixels 51 into a plurality of channels and outputs them. Accordingly, the plurality of pixels 51 are divided into a plurality of channels, and an output unit 52 is provided for each channel. For example, when a CCD linear sensor with 2048 pixels is used, the output signal from each pixel can be divided into four channels Ch1 to Ch4 for every 512 pixels that are continuous and output. In FIG. 3, only one output unit 52 is shown for simplification of the drawing.

  The correction unit 20 includes a lookup table (LUT) 21, a linearity correction unit 22, and a gain correction unit 23. The LUT 21 is provided for each of the plurality of pixels 51. Each LUT 21 is set with linearity correction data calculated based on the relationship between the incident light quantity of each pixel 51 and the output signal. The LUT 21 is for correcting the linearity of the output signal of each pixel by table conversion and correcting the difference in output signal due to the sensitivity difference of each pixel. In other words, the correction is performed so that the relationship between the input and the output which are nonlinear is linear.

  An example of linearity correction data will be described with reference to FIG. In FIG. 4, the horizontal axis represents the amount of light incident on the pixel (referred to as input level), and the vertical axis represents the level of the output signal output from the pixel (referred to as output level). As shown in FIG. 4, in the present embodiment, the linearity of the output level is corrected so that the output level matches the linear reference level indicated by the broken line. Accordingly, linearity correction data to be added to the input signal is set in the LUT 21 so that the output level corresponding to the input level of the pixel matches the reference level.

  A signal output from each pixel 51 of the CCD linear sensor 5 via the output unit 52 is transmitted to the linearity correction unit 22. The linearity correction unit 22 corrects the linearity of the input output signal for each pixel. Specifically, the linearity correction unit 22 refers to and adds the linearity correction data of the LUT 21 corresponding to the pixel 51 according to which pixel 51 the input signal is output from. Thereby, the linearity correction of the output signal from each pixel can be performed. The signal whose linearity has been corrected is transmitted to the gain correction unit 23, and gain correction is performed. Thereby, in the case of the same amount of incident light quantity, the inclination of the output signal from each pixel can be corrected, and the level of the output signal from each pixel can be made substantially constant.

  As described above, by generating linearity correction data for performing linearity correction for each pixel and performing linearity correction, even if there is a difference in sensitivity between the plurality of pixels 51, the output level is made constant. Can do. Also, by creating the linearity correction data before the mask 13 is inspected, the time required for the arithmetic processing can be shortened.

  Conventionally, the maximum output of each pixel has been corrected by performing gain correction that performs a single correction on a single input. Further, the output in the dark when the light of each pixel is not input is corrected by performing offset correction. For this reason, there is no difference in the output level of each pixel with respect to the input when this gain correction is performed. However, when there is an input that is darker (gray tone) than the incident light when this gain correction is performed, there is a difference in the linearity of the sensitivity of each pixel, resulting in variations in the output from each pixel.

  In the present embodiment, correction is performed so that the level of the output signal output from each pixel substantially matches the reference level in accordance with the linearity correction data set for each pixel. For this reason, as shown in FIG. 5, the output from each pixel, that is, the sensitivity, is made substantially constant even when gray tone light darker than the incident light used when performing gain correction is input. Can do. Even in the first pixel at the joint of each channel, there is no difference in sensitivity from other pixels. For this reason, it is possible to suppress the generation of a beard signal that has been generated due to the difference in sensitivity of the first pixel at the joint of each channel.

  Here, a method for correcting an output signal from the CCD linear sensor 5 and a defect inspection method for the mask 13 will be described with reference to FIGS. FIG. 6 is a diagram for explaining a method of creating linearity correction data of an output signal in the defect device according to the present embodiment. FIG. 7 is a flowchart for explaining a method of creating linearity correction data. As shown in FIG. 7, first, gain correction and offset correction are performed (step S1). First, as in the conventional case, offset correction is performed so that the output signals are equal to zero when the light amount from the light source is zero (second light amount). Then, a predetermined first light amount of light is emitted from the light source 14 used for inspection, and the gain is set so that the maximum output signal of each pixel becomes constant. At this time, the light is uniformly irradiated so that each pixel 51 is irradiated with the same first light amount. This reduces the level difference between the dark output between the pixels and the maximum output.

  Then, linearity correction data is created by irradiating light of a light amount between the first light amount and the second light amount, that is, gray tone light. In order to create linearity correction data, first, the gray-scale light from the light source 14 is irradiated to each pixel 51 of the CCD linear sensor 5 (step S2). At this time, the light is uniformly irradiated so that each pixel 51 is irradiated with the same gray-tone light. Then, the output signal with respect to the incident light amount of each pixel is plotted. Thereafter, while gradually decreasing the light amount, the output signal with respect to the incident light amount at each light amount is plotted. Thereby, for example, a graph as shown by the curve in FIG. 4 is obtained. In addition, as a graph of the output signal with respect to the incident light quantity, a straight line may be supplemented between plotted points, or a curve may be supplemented.

  Thereafter, as shown in FIG. 7, linearity correction data for correcting the linearity is calculated so that the output signal for each input light amount substantially matches the reference level indicated by the broken line (step S3). Then, the calculated linearity correction data is set in the LUT 21 (step S4). As shown in FIG. 6, a plurality of LUTs 21 are created for each pixel. Thereby, the linearity of each pixel can be corrected and the sensitivity difference between each pixel can be reduced.

  When a gray tone signal is input, each linearity correction data is added to the output signal of each pixel according to the amount of incident light. As a result, even when a gray tone signal is input, it is possible to suppress variations in output level due to sensitivity differences among the pixels.

  When the defect of the mask 13 is inspected, the light from the mask 13 is received using the CCD image sensor 5 in which the output signal is corrected as described above. Then, the difference (pitch shift difference signal) between the linearity-corrected signal output from the CCD linear sensor 5 and the signal shifted by the pattern pitch is calculated. The pitch shift difference signal is calculated from the difference between output signals from different pixels. Then, the pitch shift difference signal is compared with a preset slice level (threshold). As described above, no beard signal is generated even at the joint of each channel, so that the slice detection level can be set low to improve the defect detection sensitivity.

  In the above-described example, the level of the output signal from each pixel is matched with the reference level, but the present invention is not limited to this. In manufacturing, it is known that the linearity of the first pixel of each channel tends to deviate from other pixels. For this reason, the output levels of the pixels on both sides of the joint between the channels may be matched.

  By using the inspection apparatus of the present invention for inspection of masks and mask blanks, or inspection processing of semiconductor wafers, it is possible to improve the manufacturing yield of semiconductor devices by manufacturing defect substrates and manufacturing pattern substrates. . In manufacturing a typical semiconductor device, a mask original plate is set in an exposure apparatus, and a resist-formed wafer is exposed using light, an ion beam, an electron beam, or the like. The semiconductor wafer subjected to the exposure process is subjected to a development process, and a resist pattern is formed on the wafer. Thereby, a pattern substrate is manufactured. According to this pattern, a widely known thin film deposition process, etching process, oxidation process, ion implantation process, and the like are performed to form a semiconductor device. With the mask inspected using the inspection apparatus or inspection method of the present invention, or the mask using mask blanks, the exposure process in the manufacture of the semiconductor device can be carried out. Also, a semiconductor device manufacturing process can be performed on a wafer inspected using the inspection apparatus or inspection method of the present invention to manufacture a semiconductor device. Moreover, you may perform defect correction using a well-known defect correction apparatus.

  In this embodiment, an example in which a defect is inspected by reflected light from the sample surface has been described. However, the above-described defect inspection can also be performed by using scattered light on the sample surface or transmitted light that passes through the sample. is there.

  Note that the present invention can be used not only for defect inspection of mask blanks, masks, semiconductor devices, and semiconductor wafers but also for other samples. The optical system of the present invention can be applied not only to a defect inspection apparatus that is one of sample states, but also to an optical scanning device that detects a general sample state, such as a microscope. The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the same effect can be obtained by using other various optical components and optical elements without being limited to the illustrated optical system.

It is a figure which shows the structure of the defect inspection apparatus which concerns on embodiment. It is a figure which shows a part of structure of the defect inspection apparatus which concerns on embodiment. It is a figure which shows a part of structure of the defect inspection apparatus which concerns on embodiment. It is a figure for demonstrating linearity correction data. It is a figure which shows an example of the output signal of the defect inspection apparatus which concerns on embodiment. It is a figure for demonstrating the correction method which concerns on embodiment. It is a flowchart for demonstrating the production method of the linearity correction data which concerns on embodiment. It is a figure which shows an example of the output signal of the conventional defect inspection apparatus. It is a figure which shows an example of the output signal after performing offset correction / gain correction of the conventional defect inspection apparatus. It is a figure which shows an example of an output signal when the light of the gray tone of the conventional defect inspection apparatus is input. It is a figure which shows an example of the pitch shift difference signal at the time of the defect detection of the conventional defect inspection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Surface plate 2 Square pillar 3 Mask holder 4 Right angle stage for head 5 CCD linear sensor 6 Air pad 7 Wire 8 Pulley 9 Balance weight 10 Motor stage 11 Vertical drive mechanism 12 Horizontal drive mechanism 13 Mask 14 Light source 15 Mask 16 Light-shielding pattern 20 Processing device 21 LUT
22 Linearity correction unit 23 Gain correction unit

Claims (10)

An inspection apparatus that inspects the sample using an image sensor that receives light from the sample,
A plurality of pixels provided in the image sensor and outputting an output signal corresponding to the amount of incident light;
An output unit configured to divide and output the output signal output from the plurality of pixels into a plurality of channels;
Using the linearity correction data created for each of the plurality of pixels, a linearity correction unit that performs linearity correction of the output signal;
Based on the output signal linearity corrected by the linearity correction unit, a processing unit for detecting a defect,
Set gain and offset based on said output signal when irradiated with light of a first light quantity and the second light quantity, was irradiated with light of the light amount between the first light amount and the second amount The linearity correction data is created based on the output signal obtained by correcting the output signal at the time using the gain and offset,
The inspection apparatus in which the linearity correction unit performs linearity correction of the output signal for each of the plurality of pixels using the linearity correction data.   The inspection apparatus according to claim 1, wherein the linearity correction unit performs linearity correction so that the linearity of pixels on both sides of the seam of the channel substantially matches.   The inspection apparatus according to claim 1, wherein the linearity correction unit corrects linearity so that linearity of each of the plurality of pixels matches a reference level.   The inspection apparatus according to claim 1, wherein the linearity correction unit includes a lookup table in which the linearity correction data created for each of the plurality of pixels is set. The sample is a pattern substrate having a repeated pattern,
The said process part detects a defect by comparing the output signal which correct | amended the linearity, and the thing which shifted the said output signal by the pattern pitch repeatedly. Inspection equipment. Receiving light from the sample by an image sensor that divides and outputs output signals from a plurality of pixels into a plurality of channels;
Based on the output signal when the light of the first light quantity and the second light quantity is irradiated, the gain and offset of the plurality of pixels are set, and the light quantity of light between the first light quantity and the second light quantity is set. Creating linearity correction data for each of the plurality of pixels based on an output signal obtained by correcting the output signal using the gain and the offset;
Correcting the linearity of the output signal from the image sensor for each of the plurality of pixels by the linearity correction data created for performing the linearity correction of each of the output signals of the plurality of pixels;
Detecting a defect based on an output signal whose linearity is corrected.   The inspection method according to claim 6, wherein the linearity correction data is created so that the linearity of the output signals of the pixels on both sides of the seam of the channel substantially match.   The inspection method according to claim 6 or 7, wherein linearity correction data is created so that linearity of output signals of the plurality of pixels matches a reference level. The sample is a pattern substrate having a repeated pattern,
The inspection method according to any one of claims 6 to 8, comprising a step of detecting a defect by comparing an output signal in which linearity is corrected and a signal obtained by repeatedly shifting the output signal by a pattern pitch.   A manufacturing method of a pattern substrate including a step of detecting a defect of the sample by the inspection method according to claim 6.

Images