Inspection method and inspection system

Abstract

To perform an inspection at high throughput for a plurality of inspection items including a dimension of a pattern on a substrate related to the substrate after plasma etching.SOLUTION: An inspection method of a substrate in an etching system having an imaging device comprises: (A) a step of acquiring image data by imaging a substrate after plasma etching with the imaging device; and (B) a step of calculating a dimension of a pattern on the substrate after plasma etching and at least one of information on a defect on the substrate after plasma etching and information on the thickness of a film on the substrate and appearance of the substrate on the basis of the image data of the substrate after plasma etching.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to an inspection method and an inspection system. [Background technology]

[0002] Patent Document 1 discloses a system including a coating / developing apparatus and an etching apparatus. This system includes a line width inspection apparatus that inspects the developed line width and the etched line width, a film thickness measurement unit that measures the thickness of the resist film, and a defect inspection apparatus that inspects the surface defects after development and after etching. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-190446 A Summary of the Invention [Problem to be solved by the invention]

[0004] The technology disclosed herein performs high-throughput inspection of a plurality of inspection items, including dimensions of patterns on a substrate, after plasma etching. [Means for solving the problem]

[0005] One aspect of the present disclosure is a method for inspecting a substrate in an etching system equipped with an imaging device, comprising the steps of: (A) imaging a substrate after plasma etching with the imaging device to obtain image data; and (B) calculating, based on the image data of the substrate after plasma etching, at least one of dimensions of a pattern on the substrate after plasma etching, information on defects on the substrate after plasma etching, a thickness of a film on the substrate, and information on an appearance of the substrate; (C) imaging the substrate before plasma etching with the imaging device to obtain image data; (D) calculating at least one of dimensions of a pattern on the substrate before plasma etching, information on defects on the substrate before plasma etching, a thickness of a film on the substrate, and information on the appearance of the substrate based on the image data of the substrate before plasma etching; and correcting the image data of the substrate before plasma etching used in the (D) step; Including The correction step corrects the image data of the substrate before plasma etching based on a measurement result of an accumulated use time or a temperature of a light source of the imaging device and a conversion table that converts a correction amount from the accumulated use time or the temperature, which is calculated in advance. . Effect of the Invention

[0006] According to the present disclosure, it is possible to perform high-throughput inspection of a plurality of inspection items, including dimensions of patterns on a substrate, after plasma etching. [Brief description of the drawings]

[0007] [Figure 1] 1 is a diagram illustrating a schematic configuration of an etching system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing a schematic configuration of an imaging module. [Diagram 3] FIG. 2 is a vertical cross-sectional view showing a schematic configuration of an imaging module. [Figure 4] FIG. 2 is a functional block diagram of an inspection control device and a main control device related to inspection in the etching system. [Diagram 5] 1 is a flowchart illustrating an example of wafer processing, including wafer inspection, performed using the etching system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] 2. Description of the Related Art In a manufacturing process for semiconductor devices and the like, an etching process using plasma, that is, plasma etching, is performed on a substrate such as a semiconductor wafer (hereinafter referred to as a "wafer"). The results of this plasma etching process affect subsequent processing of the substrate and the performance of the semiconductor device. Therefore, it is essential to inspect the state of the substrate after the plasma etching process. Generally, the dimensions of the pattern on the substrate (line width or hole diameter, etc.) are important inspection items for the substrate after the plasma etching process, but other inspection items such as film thickness, defects, and appearance are also important. However, if a different device is provided for each inspection item, the throughput decreases.

[0009] Therefore, the technology disclosed herein makes it possible to perform high-throughput inspection of a plurality of inspection items, including dimensions of patterns on a substrate, after plasma etching.

[0010] Hereinafter, an inspection method and an etching system according to the present embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are denoted by the same reference numerals, and duplicated description will be omitted.

[0011] <Etching system> FIG. 1 is a diagram showing a schematic configuration of an etching system according to the present embodiment. 1 performs plasma etching on a substrate such as a wafer W. The etching system 1 includes vacuum transfer modules TM1 and TM2, plasma etching modules (hereinafter, abbreviated as etching modules) PM1 to PM12 as etching devices, load lock modules LL1 and LL2, an atmospheric transfer module AM, and an imaging module IM for inspection.

[0012] The vacuum transfer modules TM1 and TM2 each have reduced pressure transfer chambers 11 and 12 that are configured with a housing that is substantially polygonal in plan view (substantially rectangular in the illustrated example).

[0013] Etching modules PM1 to PM6 are connected to two opposing side surfaces of the reduced pressure transfer chamber 11. Load lock modules LL1 and LL2 are connected to one of the other two opposing side surfaces of the reduced pressure transfer chamber 11, and a path (not shown) for connection to the reduced pressure transfer chamber 12 of the vacuum transfer module TM2 is connected to the other side surface.

[0014] The etching modules PM7 to PM12 are connected to two opposing side surfaces of the reduced pressure transfer chamber 12. A path (not shown) for connecting to the reduced pressure transfer chamber 11 of the vacuum transfer module TM1 is connected to one of the other two opposing side surfaces of the reduced pressure transfer chamber 12.

[0015] The reduced pressure transfer chambers 11, 12 each have a vacuum transfer mechanism TR1, TR2 arranged therein, which is configured to be capable of transferring a wafer W, and are maintained in a reduced pressure atmosphere. The vacuum transfer mechanisms TR1, TR2 each have transfer arms AR1-AR4 that hold the wafer W during transfer. The transfer arms AR1-AR4 are configured to be able to rotate, extend and retract, and move up and down freely.

[0016] The vacuum transfer mechanism TR1 uses, for example, transfer arms AR1 and AR2 to transfer the wafer W among the load lock modules LL1 and LL2, the etching modules PM1 to PM6, and a path (not shown). The vacuum transfer mechanism TR2 uses, for example, transfer arms AR3 and AR4 to transfer the wafer W between the etching modules PM7 to PM12 and paths (not shown).

[0017] Each of the etching modules PM1 to PM12 performs plasma etching on the wafer W. Furthermore, each of the etching modules PM1 to PM12 is connected to vacuum transfer modules TM1 and TM2 via a gate valve G1.

[0018] The load lock modules LL1 and LL2 are provided to connect the vacuum transfer module TM1 and the atmospheric transfer module AM ​​(specifically, a loader module LM described later) via gate valves G2 and G3. The load lock modules LL1 and LL2 are configured to temporarily hold a wafer W. The load lock modules LL1 and LL2 are also configured so that the interior can be switched between an atmospheric pressure atmosphere and a reduced pressure atmosphere.

[0019] The atmospheric transfer module AM ​​has a loader module LM equipped with a transfer mechanism TR3 described later, and load ports LP1 to LP4 on which a FOUP (Front-Opening Unified Pod) F is placed. The FOUP F is a container capable of storing a plurality of wafers W. The atmospheric transfer module AM ​​may further have an orienter module (not shown) that adjusts the horizontal orientation of the wafer W.

[0020] The loader module LM has a rectangular housing in a plan view, and the inside of the housing is maintained at atmospheric pressure. On one side constituting the long side of the loader module LM housing, a plurality of load ports LP1 to LP4 (four in the illustrated example) are arranged side by side. On the other side constituting the long side of the loader module LM housing, load lock modules LL1 and LL2 are arranged side by side.

[0021] A transfer mechanism TR3 configured to be capable of transferring the wafer W is provided inside the housing of the loader module LM. The transfer mechanism TR3 has a transfer arm AR5 that holds the wafer W during transfer. The transfer arm AR5 is configured to be movable along the longitudinal direction of the housing of the loader module LM, and is also configured to be freely rotatable, extendable, and movable up and down.

[0022] The transfer mechanism TR3 uses, for example, a transfer arm AR5 to transfer the wafer W among the FOUP F on the load ports LP1 to LP4, the load lock modules LL1 and LL2, and the imaging module IM for inspection.

[0023] The imaging module IM is connected to, for example, one side surface constituting a short side of the housing of the loader module LM. The imaging module IM captures an image of the wafer W for inspection of the wafer W. A specific configuration of the imaging module IM will be described later.

[0024] Further, the etching system 1 includes a main control unit CU1 and an inspection control unit CU2. In one embodiment, the inspection control unit CU2 controls the process related to the imaging module IM among the various processes described in the present disclosure, and the main control unit CU1 controls the other processes. In one embodiment, the main control unit CU1 and the inspection control unit CU2 process computer-executable instructions that cause the etching system 1 to execute the various processes described in the present disclosure. The main control unit CU1 and the inspection control unit CU2 may be configured to control each of the other elements of the etching system 1 to execute the various processes described herein. In one embodiment, some or all of the main control unit CU1 and the inspection control unit CU2 may be included in the other elements of the etching system 1. For example, the main control unit CU1 and the inspection control unit CU2 may include computers 30 and 40, respectively. The computers 30 and 40 may include, for example, processing units (CPUs: Central Processing Units) 31 and 41, memory units 32 and 42, and communication interfaces 33 and 43. The processing units 31, 41 may be configured to perform various control operations based on programs stored in the storage units 32, 42. The storage units 32, 42 may include a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interfaces 33, 43 may communicate with other elements of the etching system 1 via a communication line such as a local area network (LAN). The main control unit CU1 and the inspection control unit CU2 may have a common computer. In other words, the main control unit CU1 and the inspection control unit CU2 may share a part or all of the computer.

[0025] <Imaging module IM> Next, the imaging module IM will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a cross-sectional view showing a schematic configuration of the imaging module IM. Fig. 3 is a vertical-sectional view showing a schematic configuration of the imaging module IM.

[0026] The imaging module IM has a casing 110 as shown in FIG. 2. A mounting table 120 on which a wafer W is placed is provided inside the casing 110 as shown in FIG. 3. The mounting table 120 can be rotated and stopped freely by a rotation drive unit 121 such as a motor. A guide rail 122 is provided on the bottom surface of the casing 110, and extends from one end side (the X-axis negative direction side in FIG. 3) to the other end side (the X-axis positive direction side in FIG. 3) inside the casing 110. The mounting table 120 and the rotation drive unit 121 are provided on the guide rail 122, and can be moved along the guide rail 122 by a drive unit 123.

[0027] An imaging device 130 is provided on the side surface at the other end side (the X-axis positive side in FIG. 3) inside the casing 110. For example, a wide-angle CCD camera is used as the imaging device 130. A half mirror 131 is provided near the center of the upper part of the casing 110. The half mirror 131 is provided at a position facing the imaging device 130, with the mirror surface tilted 45 degrees upward toward the imaging device 130 from a state in which the mirror surface faces vertically downward. A light source 132 is provided above the half mirror 131. The half mirror 131 and the light source 132 are fixed to the upper surface inside the casing 110. Illumination from the light source 132 passes through the half mirror 131 and is irradiated downward. Therefore, the light reflected by an object in this irradiation area is further reflected by the half mirror 131 and taken into the imaging device 130. That is, the imaging device 130 can capture an image of an object in the irradiation area by the light source 132. The captured image is input to the inspection control device CU2.

[0028] In the imaging module IM, while the wafer W moves from one end side to the other end side (from the negative X-axis direction side to the positive X-axis direction side in FIG. 4) within the casing 110 along the guide rails 122, the imaging device 130 intermittently captures images of the entire surface of the wafer W. As a result, image data of the entire surface of the wafer W is acquired in the inspection control device CU2.

[0029] <Inspection control device CU2 and main control device CU1> FIG. 4 is a functional block diagram of the inspection control device CU2 and the main control device CU1 related to inspection in the etching system 1.

[0030] 4, the inspection control device CU2 has an acquisition unit 211, an image data correction unit 212, a necessary information selection unit 213, a dimension calculation unit 214, a defect information calculation unit 215, a film thickness calculation unit 216, an appearance information calculation unit 217, a first condition correction unit 218, a second condition correction unit 219, and a processing result determination unit 220, which are realized by a processor such as a CPU reading and executing a program stored in a storage unit 42. The storage unit 42 of the inspection control device CU2 has an image data storage unit 231, a pre-processing information storage unit 232, and a post-processing information storage unit 233.

[0031] The main control device CU1 includes a determination unit 241 that is realized by a processor such as a CPU reading and executing a program stored in the storage unit 32.

[0032] The acquiring unit 211 acquires image data of the wafer W, specifically, image data of the entire surface of the wafer W, based on the imaging result of the wafer W by the imaging module IM. The image data acquired by the inspection control device CU2 is, for example, RGB data indicating luminance information of R (red), G (green), and B (blue) for each pixel. Note that data of a color system other than the RBG color system (for example, the CMYK color system) may be used as the image data. The image data acquired by the inspection control device CU2 is stored, i.e., memorized, in the image data storage unit 231.

[0033] The image data correction unit 212 corrects the image data of the wafer W acquired by the acquisition unit 211 and used in the dimension calculation unit 214 and the like. The imaging result of the imaging device 130 may change due to a change over time in the intensity of the light emitted from the light source 132 of the imaging module IM, a state of the light source 132 (for example, the temperature of the light source 132), and the like. For this reason, the image data correction unit 212 corrects the image data of the wafer W acquired by the acquisition unit 211, for example, based on the usage time of the light source 132 of the imaging module IM and the temperature of the light source 132. For this correction, for example, a conversion table is used for converting the usage time of the light source 132 and the temperature of the light source 132 into the correction amount of the image data (specifically, the correction amount of the pixel value). These conversion tables are calculated in advance and stored in the storage unit 42. For this correction, for example, the inspection control device CU2 is provided with a timer (not shown) that measures the usage time of the light source 132, and the imaging module IM is provided with a temperature sensor (not shown) that measures the temperature of the imaging device 130.

[0034] The necessary information selection unit 213 selects an inspection item for which inspection based on the image data of the wafer W is required, that is, information that needs to be calculated from the image data of the wafer W. This selection is performed, for example, based on inspection information (described later) input from the main control device CU1.

[0035] The inspection according to this embodiment is performed on at least the wafer W after plasma etching out of the wafer W before plasma etching and the wafer W after plasma etching, and may also be performed on the wafer W before plasma etching. Therefore, the necessary information selection unit 213 selects inspection items for at least the wafer W after plasma etching, and may also select inspection items for the wafer W before plasma etching. The inspection items selected by the necessary information selection unit 213 may be partly or entirely common between the wafer W after plasma etching and the wafer W before plasma etching, or may all be different.

[0036] In addition, for the wafer W after plasma etching, the necessary information selection unit 213 selects, as inspection items, at least one of the dimensions of the pattern on the wafer W, information on defects on the wafer W, the thickness of the film on the wafer W, and information on the appearance of the wafer W.

[0037] The dimension calculation unit 214 calculates the dimensions (specifically, planar dimensions) of the pattern on the wafer W based on the image data of the wafer W. The pattern dimensions are, for example, the line width in the case of a line-and-space pattern, and the hole diameter in the case of a hole pattern. The calculation by the dimension calculation unit 214 uses dimension conversion data that converts the above dimensions from the luminance information of the image data of the wafer W. The dimension conversion data is acquired in advance and stored in the storage unit 42.

[0038] The defect information calculation unit 215 calculates information on defects on the wafer W based on the image data of the wafer W. Specifically, the defect information calculation unit 215 calculates, for example, the number of defects on the surface of the wafer W based on the image data of the wafer W and defect detection data (data for detecting defects based on image data). More specifically, the defect information calculation unit 215 calculates, for example, the difference between each pixel of the wafer portion in the image data of the wafer W and an adjacent pixel, that is, differential data, and detects micro-defects based on the differential data and the defect detection data, and calculates the number of micro-defects. The defect information calculated by the defect information calculation unit 215 may include at least one of the size and position of the micro-defects instead of or in addition to the number of micro-defects. The defect information may be at least two of the number, size, and position of the micro-defects indexed based on the defect detection data. The defect detection data is acquired in advance and stored in the storage unit 42.

[0039] The film thickness calculation unit 216 calculates the thickness of a film on the wafer W based on the image data of the wafer W. Specifically, the film thickness calculation unit 216 calculates, for example, the thickness of a layer to be etched on the wafer W and the film thickness of a mask pattern (e.g., a resist pattern) formed on the layer to be etched based on the image data of the wafer W. The film thickness calculation unit 216 uses film thickness conversion data for converting the thickness of the film from brightness information of the image data of the wafer W. The film thickness conversion data is acquired in advance and stored in the storage unit 42.

[0040] The dimension calculation unit 214, the defect information calculation unit 215, and the film thickness calculation unit 216 may calculate information such as pattern dimensions for only a portion of an area constituting the wafer W, based on image data of that area.

[0041] Furthermore, the dimension calculation unit 214, the defect information calculation unit 215, and the film thickness calculation unit 216 may calculate corresponding information such as the dimension of a pattern for each region constituting the wafer W, based on the image data of the region. That is, the dimension calculation unit 214, the defect information calculation unit 215, and the film thickness calculation unit 216 may acquire an in-plane distribution of the corresponding information on the wafer W, based on the image data of the wafer W.

[0042] The appearance information calculation unit 217 calculates, i.e., acquires, information on the appearance of the wafer W based on the image data of the wafer W. The appearance information of the wafer W calculated by the appearance information calculation unit 217 is, for example, information obtained by performing image processing on the image data of the entire surface of the wafer W. Specifically, the appearance information of the wafer W is, for example, information obtained by multiplying the R luminance value, the G luminance value, and the B luminance value of the image data of the wafer W, which is RGB data, by a coefficient predetermined for each color. The appearance information of the wafer W may be information obtained by extracting a part of the image data of the entire surface of the wafer W (for example, information obtained by extracting only the image data of a specific chip). Furthermore, the appearance information of the wafer W may be the image data of the wafer W acquired by the acquisition unit 211 or the image data itself corrected by the image data correction unit 212. Information required for the appearance information calculation unit 217 to calculate / acquire the information on the appearance of the wafer W (for example, the above-mentioned coefficients and the positions of the parts to be extracted) is acquired in advance as appearance calculation data and stored in the storage unit 42.

[0043] The dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217 perform the above-mentioned calculation / acquisition for the post-plasma etched wafer W. The information for the post-plasma etched wafer W calculated / acquired by the dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217 is stored, i.e., memorized, in the post-processing information storage unit 233.

[0044] Furthermore, the dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217 may perform the above-mentioned calculation / acquisition on the pre-plasma etching wafer W. The information on the pre-plasma etching wafer W calculated / acquired by the dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217 is stored, i.e., memorized, in the pre-processing information storage unit 232.

[0045] The above-mentioned dimension calculation unit 214, defect information calculation unit 215, film thickness calculation unit 216, and appearance information calculation unit 217 constitute a "calculation unit" according to the present disclosure.

[0046] The first condition correction unit 218 determines whether or not correction of the processing conditions for the plasma etching for the wafer W is necessary, based on information about the wafer W before plasma etching calculated by the dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217. Specifically, the first condition correction unit 218 determines that correction of the processing conditions for the plasma etching for the wafer W is necessary, for example, when the thickness of the etching target layer on the wafer W before plasma etching calculated by the film thickness calculation unit 216 is greater than a threshold value.

[0047] Furthermore, the first condition correction unit 218 corrects the processing conditions of the plasma etching for the wafer W based on the information about the wafer W before the plasma etching. Specifically, the first condition correction unit 218 calculates a correction amount of the processing conditions of the plasma etching for the wafer W based on, for example, the information about the wafer W before the plasma etching. More specifically, when the thickness of the etching target layer on the wafer W before the plasma etching calculated by the film thickness calculation unit 216 is greater than a threshold value, the first condition correction unit 218 calculates a correction amount of the processing time of the plasma etching for the wafer W based on the thickness so that the processing time is extended.

[0048] The etching system 1 corrects the processing conditions of the plasma etching process based on the correction amount calculated by the first condition correcting unit 218, and performs the plasma etching process on the corresponding wafer W under the corrected processing conditions. In other words, the first condition correction unit 218 is intended to feed forward information about the wafer W before plasma etching, calculated by the dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217, to plasma etching by the etching system 1.

[0049] Data necessary for the first condition correction unit 218 to determine whether or not the processing conditions need to be corrected and to calculate the amount of correction based on the information about the wafer W before the plasma etching is acquired in advance as first correction data and stored in the storage unit 42. The first correction data includes, for example, an inspection item (information) used in the above determination and its threshold value, a table in which the type of inspection item whose calculation result exceeds the threshold value is associated with the type of processing condition to be corrected, and a table in which the calculation result of the inspection item is associated with the amount of correction of the processing condition.

[0050] The second condition correction unit 219 judges whether or not correction of processing conditions for the subsequent plasma etching for the wafer W is necessary, based on information about the wafer W after the plasma etching calculated by the dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217. Specifically, when the film thickness calculation unit 216 calculates the thickness of the resist pattern formed on the etching target layer on the wafer W after the plasma etching, the second condition correction unit 219 judges that correction of processing conditions for the subsequent plasma etching for the wafer W is necessary, for example, when the thickness of the resist pattern is not within an allowable range.

[0051] Further, the second condition correction unit 219 corrects the processing conditions of the plasma etching for the subsequent wafers W based on the information on the wafer W after the plasma etching. Specifically, the second condition correction unit 219 calculates the correction amount of the processing conditions of the plasma etching for the subsequent wafers W based on, for example, the information on the wafer W after the plasma etching. More specifically, for example, when the film thickness calculation unit 216 calculates the thickness of the resist pattern formed on the etching target layer on the wafer W after the plasma etching, the second condition correction unit 219 calculates the correction amount of the processing time of the plasma etching for the subsequent wafers W based on the thickness when the thickness of the resist pattern is smaller than a threshold value, so that the processing time of the plasma etching for the subsequent wafers W is shortened.

[0052] Furthermore, the second condition correction unit 219 may determine whether or not correction of processing conditions for plasma etching for the subsequent wafers W is necessary based on the difference in information about the wafer W before and after plasma etching, which is calculated by the dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217. Specifically, when the film thickness calculation unit 216 calculates the thickness of the resist pattern formed on the etching target layer on the wafer W before and after plasma etching, the second condition correction unit 219 makes a determination, for example, as follows. That is, when the difference in thickness of the resist pattern before and after plasma etching, i.e., the reduction amount, is not within an allowable range, the second condition correction unit 219 determines that correction of processing conditions for plasma etching for the subsequent wafers W is necessary.

[0053] The second condition correction unit 219 may also correct the processing conditions of the plasma etching for the subsequent wafers W based on the difference in information about the wafer W before and after the plasma etching. Specifically, the second condition correction unit 219 calculates the correction amount of the processing conditions of the plasma etching for the subsequent wafers W based on, for example, the difference in information about the wafer W before and after the plasma etching. More specifically, for example, when the film thickness calculation unit 216 calculates the thickness of the resist pattern formed on the etching target layer on the wafer W before and after the plasma etching, the second condition correction unit 219 calculates the correction amount as follows. That is, when the difference in thickness of the resist pattern before and after the plasma etching, i.e., the reduction amount, is smaller than a threshold value, the second condition correction unit calculates the correction amount of the processing time of the plasma etching for the subsequent wafers W based on the reduction amount so that the processing time of the plasma etching for the subsequent wafers W is shortened.

[0054] The etching system 1 corrects the processing conditions of the plasma etching process based on the correction amount calculated by the second condition correcting unit 219, and performs the plasma etching process on the corresponding wafer W under the corrected processing conditions. In other words, the second condition correction unit 219 is intended to feed back information about the wafer W after plasma etching calculated by the dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217 to the plasma etching by the etching system 1.

[0055] Data necessary for the second condition correction unit 219 to determine whether or not the processing conditions need to be corrected and to calculate the amount of correction based on the information on the wafer W after the plasma etching is acquired in advance as second correction data and stored in the storage unit 42. The second correction data includes, for example, the inspection items (information) used in the above determination, their associated threshold values ​​and the above-mentioned allowable ranges, a table in which the types of inspection items that are below the threshold values ​​are associated with the types of processing conditions to be corrected, and a table in which the calculation results of the inspection items are associated with the amounts of correction of the processing conditions.

[0056] The processing result determination unit 220 determines the result of the performed plasma etching based on the information about the wafer W after the plasma etching calculated by the dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217. The processing result determination unit 220 determines the result of the plasma etching, i.e., the level of performance, based on at least one of the information about the wafer W after the plasma etching calculated by the dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217, for example.

[0057] The determination of the result of the plasma etching by the process result determination unit 220 may also use information about the wafer W before plasma etching calculated by the dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217. Specifically, for example, the process result determination unit 220 may determine the level of the result of the plasma etching based on the difference between the information about the wafer W before the plasma etching and the information about the wafer W after the plasma etching.

[0058] A plurality of types of the above-mentioned dimension conversion data, defect detection data, film thickness conversion data, appearance calculation data, first correction data, second correction data, and result determination data may be stored in the storage unit 42. For example, different dimension conversion data, defect detection data, film thickness conversion data, appearance calculation data, first correction data, second correction data, and result determination data may be stored in the storage unit 42 depending on the type of the etching target layer.

[0059] Data necessary for the processing result determination unit 220 to determine the result of the plasma etching based on the information on the wafer W after the plasma etching is acquired in advance as result determination data and stored in the storage unit 42. The result determination data includes, for example, inspection items (information) used for the determination, and a table in which the calculation results of the inspection items are associated with levels.

[0060] When performing wafer processing including inspection of a wafer W, the main control device CU1 acquires a processing recipe for the wafer W to be processed in advance or acquires it when starting the processing, and stores or memorizes it in the storage unit 32. The processing recipe includes an inspection recipe. In the inspection recipe, for example, the following is set or specified in advance for the target wafer W: (1) Information on whether inspection is required before plasma etching (2) Inspection items that require calculation in inspections after plasma etching (3) Inspection items that require calculation in the inspection before plasma etching (set only if necessary) (4) Area on wafer W where inspection items should be calculated (5) Data to be used for calculating the inspection items (e.g., type of dimension conversion data, type of data for determining results, etc.) (6) First correction data to be used for the target wafer W (set only if necessary) (7) Second correction data to be used for the target wafer W (set only if necessary) (8) Data for determining the result to be used for the target wafer W (set only if necessary)

[0061] Furthermore, the determination unit 241 of the main control device CU1 determines whether or not inspection before plasma etching is required for the wafer W to be processed, based on an inspection recipe included in the processing recipe set for that wafer W. Depending on the result of this determination, an inspection before plasma etching is performed by the inspection control device CU2.

[0062] <Wafer processing> Next, a wafer process including inspection of the wafer W performed using the etching system 1 will be described with reference to Fig. 5. Fig. 5 is a flowchart for explaining an example of the wafer process performed using the etching system 1.

[0063] (Step S1) First, as shown in FIG. 5, the determining unit 241 of the main control device CU1 determines whether or not the wafer W to be processed needs to be inspected before plasma etching. This determination is made based on, for example, a processing recipe set for the wafer W to be processed. An example of the wafer W to be processed is a wafer having a silicon oxide layer and a resist layer formed in that order on the surface of the wafer W. For example, this wafer is one in which lines and spaces are formed in the oxide layer using the resist layer as a mask. Another example of the wafer W to be processed is a wafer having a polysilicon layer and a resist layer formed in this order on the surface of the wafer W. For example, this wafer is a wafer in which a gate is formed in the polysilicon layer using the resist layer as a mask.

[0064] (Step S2) If it is determined that the inspection before plasma etching is not necessary (if NO), the process proceeds to step S8, but on the other hand, if it is determined that the inspection before plasma etching is necessary (if YES), the inspection before plasma etching of the wafer W to be processed is started, and the wafer W to be processed is transported to the imaging module IM for inspection. Specifically, under the control of the main control device CU1, the wafer W to be processed is taken out of the FOUP F by the transport mechanism TR3 and transported to the imaging module IM for inspection.

[0065] At this time, the main controller CU1 outputs, for example, the following items (3) to (6) as pre-etching inspection information to the inspection controller CU2 based on the processing recipe set for the wafer W to be processed. (3) Inspection items that require calculation in the inspection before plasma etching (4) Area on wafer W where inspection items should be calculated (5) Data to be used in calculating test items (6) First correction data to be used for the target wafer W

[0066] (Step S3) Thereafter, under the control of the inspection control device CU2, in the imaging module IM, an image is captured by the imaging device 130 so as to scan the surface of the wafer W before the plasma etching.

[0067] (Step S4) Next, the acquisition unit 211 of the inspection control device CU2 acquires image data of the wafer W based on the image capturing result of the wafer W before plasma etching by the imaging device 130, and stores the image data in the image data storage unit 231. The image data acquired and stored here is, for example, RGB data.

[0068] (Step S5) Next, the inspection control device CU2 calculates and stores information on the inspection items of the wafer W before plasma etching.

[0069] Specifically, the inspection items that need to be inspected are selected based on the above information (3) included in the above-mentioned pre-etching inspection information by the necessary information selection unit 213. As a result, at least one of the dimensions of the pattern on the wafer W, information on defects on the wafer W, the thickness of the film on the wafer W, and information on the appearance of the wafer W is selected. Then, information on the selected inspection item is calculated by a corresponding calculation unit among the dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217 based on the image data of the wafer W before plasma etching, and is stored in the pre-processing information storage unit 232.

[0070] For example, the dimension calculation unit 214 calculates the dimension of the pattern on the above region as the dimension of the pattern on the wafer W before plasma etching, based on the image data of the region specified in (4) contained in the inspection information and the dimension conversion data specified in (5) above.

[0071] When defects are selected as an inspection item that requires inspection, the defect information calculation unit 215 calculates the number of defects on the entire surface of the wafer W as information on the defects on the wafer W before plasma etching, for example, based on the image data of the entire wafer W and the defect detection data specified in (5) above that is included in the inspection information.

[0072] When the film thickness is selected as an inspection item that needs to be inspected, the film thickness calculation unit 216 calculates the film thickness on the region as the thickness of the film on the wafer W before plasma etching, for example, based on the image data of the region specified in (4) included in the inspection information and the film thickness conversion data specified in (5). When the film thickness of the resist pattern on the etching target layer is calculated, it may be calculated based on the image data of the region in which the number of openings formed is small and most of the region is covered with the resist film. When the film thickness of the etching target is calculated when a resist pattern is formed on the etching target layer, it may be calculated based on the image data of the region in which the etching target layer is exposed from the resist pattern, i.e., the region corresponding to the opening portion of the resist pattern.

[0073] When appearance is selected as an inspection item that requires inspection, the appearance information calculation unit 217 calculates image data by extracting a portion of the image data of the wafer W as information on the appearance of the wafer W before plasma etching, for example, based on the appearance calculation data specified in (5) above contained in the inspection information.

[0074] The image data of the wafer W before plasma etching used for calculating the information of the inspection item in step S5 may be data corrected by the image data correction unit 212. The image data correction unit 212 corrects the image data of the wafer W before plasma etching based on, for example, the measurement result of the accumulated usage time of the light source 132 by a timer (not shown) or the measurement result of the temperature of the light source 132 by a temperature sensor (not shown) and the above-mentioned conversion table.

[0075] (Step S6) Next, the first condition correcting unit 218 determines whether or not the processing conditions for the plasma etching for the wafer W to be processed need to be corrected, based on the information on the inspection items calculated in step S5. Specifically, the first condition correction unit 218 determines whether or not the above correction is necessary based on, for example, the information on the inspection item calculated in step S5 and the first correction data specified in (5) above, which is included in the pre-etching inspection information.

[0076] In addition, if the information on the inspection item calculated in step S5 indicates an abnormal value (for example, if the number of defects exceeds a threshold value or the appearance data matches abnormal data), processing from step S6 onwards may be stopped, and further, operation of the etching system 1 may be stopped and wafer processing for the subsequent wafers W may be stopped.

[0077] (Step S7) In step S6, if it is determined that correction is not necessary (NO), the process proceeds to step S9, but if it is determined that correction is necessary (YES), the first condition correction unit 218 calculates the correction amount of the plasma etching processing conditions for the wafer W to be processed and outputs it to the main control unit CU1. Specifically, the first condition correction unit 218 calculates a correction amount of the plasma etching processing condition for the wafer W to be processed based on, for example, the information of the inspection item calculated in step S5 and the first correction data specified in (6) above included in the above-mentioned pre-etching inspection information, and outputs the calculated correction amount to the main control device CU1. Then, the process proceeds to step S9.

[0078] (Step S8) For example, in step S8 which is performed in parallel with the above-mentioned steps S4 to S7, the wafer W to be processed is transferred from the inspection imaging module IM to a desired etching module (here, it is assumed that the wafer W is transferred to the etching module PM1).

[0079] Specifically, under the control of the main controller CU1, the wafer W to be processed is taken out of the FOUP F or the imaging module IM for inspection by the transfer mechanism TR3, and transferred to, for example, the load lock module LL1. Then, the wafer W to be processed is taken out of the load lock module LL1 by the vacuum transfer mechanism TR1, and transferred to the etching module PM1. Then, the process proceeds to step S9.

[0080] (Step S9) In step S9, plasma etching is performed on the target wafer W. In step S9, which is performed following the calculation of the correction amount in step S7, plasma etching is performed on the target wafer W under processing conditions corrected based on the correction amount calculated in step S7. If it is determined in step S6 that correction is not required or if it is determined in step S1 that plasma etching processing is not required, in step S9, plasma etching is performed under processing conditions predetermined in the processing recipe.

[0081] (Step S10) After the plasma etching, inspection of the wafer W after the plasma etching is started, and the wafer W is transferred to an imaging module IM for inspection. Specifically, under the control of the main control device CU1, first, the plasma-etched wafer W is removed from the etching module PM1 by the vacuum transfer mechanism TR1 and transferred to, for example, a load lock module LL2. Then, the plasma-etched wafer W is transferred from the load lock module LL2 to an imaging module IM for inspection by the vacuum transfer mechanism TR1.

[0082] At this time, the main control device CU1 outputs, based on the processing recipe set for the wafer W, for example, the following (2), (4), (5), (7), and (8) to the inspection control device CU2 as post-etching inspection information. (2) Inspection items that require calculation in inspections after plasma etching (4) Area on wafer W where inspection items should be calculated (5) Data to be used in calculating test items (7) Second correction data to be used for the target wafer W (8) Data for determining the result to be used for the target wafer W

[0083] (Step S11) Thereafter, under the control of the inspection control device CU2, in the imaging module IM, an image is captured by the imaging device 130 so as to scan the surface of the wafer W after the plasma etching.

[0084] (Step S12) Next, the acquisition unit 211 of the inspection control device CU2 acquires image data of the wafer W based on the image capturing result of the wafer W after the plasma etching by the imaging device 130, and stores the image data in the image data storage unit 231. The image data acquired and stored here is, for example, RGB data.

[0085] (Step S13) Subsequently, the inspection control device CU2 calculates and stores information on the inspection items of the wafer W after the plasma etching.

[0086] Specifically, the inspection items that need to be inspected are selected based on the above information (2) included in the above-mentioned post-etching inspection information by the necessary information selection unit 213. As a result, at least one of the dimensions of the pattern on the wafer W, information on defects on the wafer W, the thickness of the film on the wafer W, and information on the appearance of the wafer W is selected. Then, information on the selected inspection item is calculated by a corresponding calculation unit among the dimension calculation unit 214, the defect information calculation unit 215, the film thickness calculation unit 216, and the appearance information calculation unit 217 based on the image data of the wafer W after plasma etching, and is stored in the post-processing information storage unit 233.

[0087] For example, the dimension calculation unit 214 calculates the dimension of the pattern on the above region as the dimension of the pattern on the wafer W after plasma etching, based on the image data of the region specified in (4) contained in the inspection information and the dimension conversion data specified in (5) above.

[0088] When defects are selected as an inspection item that requires inspection, the defect information calculation unit 215 calculates the number of defects on the entire surface of the wafer W as information on the defects on the wafer W after plasma etching, for example, based on the image data of the entire wafer W and the defect detection data specified in (5) above that is included in the inspection information.

[0089] When film thickness is selected as an inspection item that requires inspection, the film thickness calculation unit 216 calculates the thickness of the film on the above region as the thickness of the film on the wafer W after plasma etching, for example, based on the image data of the region specified in (4) above included in the inspection information and the film thickness conversion data specified in (5) above.

[0090] When appearance is selected as an inspection item that requires inspection, the appearance information calculation unit 217 calculates image data by extracting a portion of the image data of the wafer W as information on the appearance of the wafer W after plasma etching, for example, based on the appearance calculation data specified in (5) above contained in the inspection information.

[0091] The image data of the wafer W after plasma etching used for calculating the information on the inspection items in step S13 may be data corrected by the image data correction unit 212.

[0092] (Step S14) Next, the processing result determination unit 220 determines the result of the plasma etching based on the information of the inspection items calculated in step S13. Specifically, the process result determination unit 220 determines the result of the plasma etching, that is, the quality level, based on at least one of the pieces of information on the inspection items calculated in step S13. For this determination, a difference between the information on the examination item calculated in step S13 and the information on the examination item calculated in step S5 corresponding to the information on the examination item may be used, which allows for a more accurate determination.

[0093] In addition, if the information on the inspection item calculated in step S13 indicates an abnormal value (for example, if the number of defects exceeds a threshold value or the appearance data matches abnormal data), operation of the etching system 1 may be stopped and wafer processing for subsequent wafers W may be discontinued.

[0094] (Step S15) The determination result of the plasma etching by the processing result determination unit 220 is output to, for example, a quality control server outside the etching system 1.

[0095] (Step S16) Further, second condition correcting unit 219 calculates the correction amount of the processing condition for the subsequent plasma etching for wafer W, and outputs it to main controller CU1. Specifically, the second condition correction unit 219 calculates a correction amount for the processing conditions of the plasma etching for the subsequent wafers W, based on, for example, the information on the inspection items calculated in step S13 and the second correction data specified in (7) above, which is included in the post-etching inspection information. This calculation may use the difference between the information of the inspection item calculated in step S13 and the information of the inspection item calculated in step S5 corresponding to the information, thereby making it possible to calculate more appropriate processing conditions.

[0096] (Step S17) For example, in step S17 performed in parallel with the above-mentioned steps S11 to S16, the plasma-etched wafer W is unloaded from the etching system 1. Specifically, under the control of the main controller CU1, the transport mechanism TR3 unloads the plasma-etched wafer W from the inspection imaging module IM to the FOUP F.

[0097] The above steps are performed for each wafer W.

[0098] As described above, in the inspection according to the present embodiment, based on the image data of the wafer W after plasma etching acquired based on the imaging result of the imaging module IM of the etching system 1, at least one of the dimensions of the pattern on the wafer W after plasma etching, information on defects on the wafer W after plasma etching, the thickness of the film on the wafer W, and the method of the appearance of the wafer W is calculated. That is, in the inspection according to the present embodiment, the image data of the wafer W after plasma processing used to calculate the information of each inspection item can be created from the results of imaging at the same timing by the same imaging module IM. Therefore, it is not necessary to transport the wafer W to a different module for each inspection item. Therefore, it is possible to perform high-throughput inspection of multiple inspection items including the dimensions of the pattern on the wafer W after plasma etching.

[0099] In addition, in this embodiment, for the same reasons as for the wafer W after plasma etching, inspection can be performed with high throughput on multiple inspection items, including the dimensions of the patterns on the wafer W, for the wafer W before plasma etching.

[0100] Furthermore, in this embodiment, the image data used to calculate information on various inspection items is corrected by the image data correction unit 212 based on the accumulated usage time of the light source 132, etc. This makes it possible to more accurately calculate the dimensions of the pattern on the wafer W after plasma etching, etc. This makes it possible to more accurately determine the results of the plasma etching.

[0101] In this embodiment, the first condition correcting unit 218 calculates the processing conditions for the plasma etching of the target wafer W based on the calculation results of the information of the inspection items related to the wafer W before the plasma etching. Therefore, appropriate plasma etching processing results can be obtained for the target wafer W.

[0102] Furthermore, in this embodiment, the second condition correction unit 219 calculates processing conditions for the plasma etching of the subsequent wafers W based on the calculation results of the information on the inspection items related to the wafer W after the plasma etching. Therefore, appropriate plasma etching processing results can be obtained for the subsequent wafers W.

[0103] <Variation 1> The wafer processing described with reference to FIG. 5 may be performed for each product wafer W, and the following may be performed automatically for an inspection wafer W different from the product wafer W. That is, a step of capturing an image of the inspection wafer W after plasma etching with an imaging module IM to obtain image data of the inspection wafer W, and a step of inspecting the inspection wafer W based on the image data of the inspection wafer after plasma etching may be performed automatically. By performing the inspection in this manner, the soundness of the etching system including the etching characteristics can be ensured. In other words, it can be determined whether the desired etching performance is obtained.

[0104] The inspection wafer W is, for example, a wafer W on which only an etching target layer is formed and no mask pattern is formed. For example, a plurality of inspection wafers W are collectively accommodated in a specific FOUP F on a load port LP1 or the like.

[0105] The timing at which the above-mentioned processes for the inspection wafer W are performed is determined by the main control device CU1 based on the following information, for example. The following information is stored in the storage unit 32, for example. -Pre-specified frequency (e.g. number of sheets to be processed, number of lots to be processed, cumulative processing time, etc.) Status of maintenance of the etching system 1 (e.g., information on whether maintenance has been performed) History of plasma etching of product substrates in the etching system 1 (e.g., information on whether processing conditions that generate a large amount of reaction products were continuous or not)

[0106] The determination as to whether the above-mentioned predetermined condition is satisfied is performed, for example, by the main control device CU1, and information required for the determination is obtained in advance and stored in the storage unit 32, for example.

[0107] In the process of inspecting the inspection wafer W based on image data of the inspection wafer W after plasma etching, for example, the inspection control device CU2 calculates information on the same inspection items for the inspection wafer W after plasma etching as for the product wafer W after plasma etching. Furthermore, the processing result of the plasma etching on the inspection wafer W may be determined in the same manner as the plasma etching on the product wafer W. In this case, not only the information on the inspection items of the inspection wafer W after plasma etching, calculated based on the image data of the inspection wafer W after plasma etching, but also the information on the inspection items of the inspection wafer W before plasma etching, calculated based on the image data of the inspection wafer W before plasma etching, may be used to determine the processing result of the plasma etching.

[0108] The inspection using the inspection wafer W may be performed for each of the etching modules PM1 to PM12.

[0109] <Variation 2> In the above embodiment, the "calculation unit" according to the present disclosure calculates, from image data of the wafer W after plasma etching, at least one of the pattern dimensions on the wafer W, information on defects on the wafer W, the thickness of a film on the wafer W, and information on the appearance of the wafer W, as inspection items for the wafer W after plasma etching. The "calculation unit" according to the present disclosure may further calculate, from image data of the wafer W after plasma etching, a three-dimensional shape of a pattern on the wafer W, as an inspection item for the wafer W after plasma etching. The three-dimensional shape of the pattern is, for example, the three-dimensional shape of a line of a line pattern.

[0110] In order to calculate the three-dimensional shape, the imaging module IM may be provided with a plurality of light sources that emit light having different wavelengths. Then, image data of the wafer W may be acquired for each wavelength of light, and the three-dimensional shape may be acquired based on the acquired results.

[0111] <Other Modifications> In the above embodiment, the imaging module IM is configured to image the wafer W located in an atmospheric pressure atmosphere. Alternatively, the imaging module IM may be configured to image the wafer W located in a reduced pressure atmosphere. In this case, the imaging module IM is provided, for example, at any of the etching modules PM1 to PM12 in FIG. 1. In the above case, the imaging module IM may have a configuration similar to that shown in FIG. 2 and FIG. 3, or when it is difficult for the imaging device 130 to operate accurately in a reduced pressure atmosphere, the imaging device 130 may be provided outside the casing 110, and the imaging device 130 may image the wafer W in the casing 110 through an optical window provided in a side wall or the like of the casing 110.

[0112] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0113] 1 Etching System IM Imaging module PM1~PM12 Plasma Etching Modules W wafer

Claims

1. A method for inspecting a substrate in an etching system including an imaging device, comprising: (A) capturing an image of a substrate after plasma etching with the imaging device to obtain image data; (B) calculating, based on image data of the substrate after plasma etching, at least one of dimensions of a pattern on the substrate after plasma etching, information on defects on the substrate after plasma etching, a thickness of a film on the substrate, and information on an appearance of the substrate; (C) capturing an image of the substrate before plasma etching using the imaging device to obtain image data; (D) calculating, based on image data of the substrate before plasma etching, at least one of dimensions of a pattern on the substrate before plasma etching, information on defects on the substrate before plasma etching, a thickness of a film on the substrate, and information on an appearance of the substrate; and correcting image data of the substrate before plasma etching used in the step (D), The correction step corrects image data of the substrate before plasma etching based on a measurement result of a cumulative usage time or a temperature of a light source of the imaging device and a conversion table that converts a correction amount from the cumulative usage time or the temperature, the conversion table being calculated in advance.

2. determining whether or not a substrate inspection is required before plasma etching; 2. The inspection method according to claim 1, wherein the steps (C) and (D) are performed when it is determined that a substrate inspection before plasma etching is necessary.

3. 3. The inspection method according to claim 1, wherein the step (D) further comprises calculating a three-dimensional shape of the pattern on the substrate before plasma etching.

4. 4. The inspection method according to claim 1, further comprising a step of determining a result of the plasma etching based on the information after the plasma etching obtained in the step (B).

5. 5. The inspection method according to claim 1, further comprising correcting image data of the substrate after the plasma etching used in the step (B).

6. 6. The inspection method according to claim 1, wherein the step (B) further comprises calculating a three-dimensional shape of the pattern on the substrate after plasma etching.

7. The step (A) for a testing substrate; 7. The inspection method according to claim 1, further comprising the steps of: (E) performing an inspection based on image data of the inspection substrate after plasma etching; and (C) automatically performing the inspection based on image data of the inspection substrate after plasma etching.

8. 8. The inspection method according to claim 7, further comprising a step of determining the timing for performing the steps (A) and (E) on the inspection substrate based on at least one of a pre-specified frequency, a maintenance status, and a history of plasma etching on the product substrate.

9. A method for inspecting a substrate, comprising: (a) calculating at least one of dimensions of a pattern on the substrate after plasma etching, information on defects on the substrate after plasma etching, a thickness of a film on the substrate, and information on an appearance of the substrate based on image data of the substrate after plasma etching acquired in an etching system including an imaging device; (b) calculating at least one of dimensions of a pattern on the substrate before plasma etching, information on defects on the substrate before plasma etching, a thickness of a film on the substrate, and information on an appearance of the substrate before plasma etching, based on image data of the substrate before plasma etching acquired in the etching system; correcting image data of the substrate before plasma etching used in the step (b); The correction step corrects image data of the substrate before plasma etching based on a measurement result of a cumulative usage time or a temperature of a light source of the imaging device and a conversion table that converts a correction amount from the cumulative usage time or the temperature, the conversion table being calculated in advance.

10. determining whether or not a substrate inspection is required before plasma etching; 10. The inspection method according to claim 9, wherein the step (b) is performed when it is determined that a substrate inspection before plasma etching is necessary.

11. 11. The inspection method according to claim 9, wherein the step (b) further comprises calculating a three-dimensional shape of the pattern on the substrate before plasma etching.

12. 12. The inspection method according to claim 9, further comprising the step of determining a result of the plasma etching based on the information after the plasma etching obtained in the step (a).

13. 13. The inspection method according to claim 9, further comprising correcting image data of the substrate after plasma etching used in the step (a).

14. 14. The inspection method according to claim 9, wherein the step (b) further comprises calculating a three-dimensional shape of the pattern on the substrate after plasma etching.

15. an imaging device for imaging the substrate; an etching apparatus for performing plasma etching on a substrate; a calculation unit that calculates at least one of dimensions of a pattern on the substrate after plasma etching, information on defects on the substrate after plasma etching, a thickness of a film on the substrate, and information on an appearance of the substrate based on image data of the substrate after plasma etching captured by the imaging device, the calculation unit further calculates, based on image data of the substrate before plasma etching captured by the imaging device, at least one of dimensions of a pattern on the substrate before plasma etching, information on defects on the substrate before plasma etching, a thickness of a film on the substrate, and information on an appearance of the substrate; an image data correction unit that corrects image data of the substrate before plasma etching used in the calculation unit, an etching system, wherein the image data correction unit corrects the image data of the substrate before plasma etching based on a measurement result of an accumulated usage time or a temperature of a light source of the imaging device and a conversion table that converts a correction amount from the accumulated usage time or the temperature, the conversion table being calculated in advance.

Images