JP5408975B2 - Inspection position determination method, inspection information management system, and inspection support method - Google Patents

Description

  The present invention relates to an inspection position determination method, an inspection information management system, and an inspection method, and in particular, in the inspection process performed in the process of manufacturing a device such as a semiconductor element, a flat panel, and a solar cell in units of substrates, The present invention relates to an inspection position determination method for determining an inspection position on a substrate, an inspection information management system for managing information on the inspection item, and an inspection method for performing an inspection based on the inspection position on the substrate corresponding to the inspection item.

  Industrial products are manufactured through a plurality of processes, and many inspections are performed in the process. Industrial products include devices that are devices or apparatuses having specific functions, and examples include semiconductor elements. In order to form an insulating film and a circuit pattern, a semiconductor element is subjected to a plurality of processes such as diffusion of an oxide film, etching, ion implantation, sputtering, and cleaning, and a plurality of semiconductor elements are arranged on a silicon wafer as a substrate. Manufactured in the state. At that time, shape data is measured for inspection items such as width and thickness for each specific process. Alternatively, electrical characteristic data is measured for inspection items such as resistance and conductivity. And 100% inspection is performed after the last process in the manufacturing process of a semiconductor element, and only good products are shipped.

  Semiconductor devices are manufactured in units of wafers, so in each inspection process during manufacturing, specific elements on the wafer are selected and measured, and their average values and standard deviations are managed as quality records in units of wafers. It is common to do.

  However, if there is an abnormality in the 100% inspection after the final process, even if you follow up the inspection results during the manufacturing process, you cannot perform an analysis that takes into account the correspondence with the arrangement of elements on the wafer. It is impossible to specify which process is the main cause of the failure. In order to perform complete quality control, all the measurement items should ideally be managed on a chip basis. However, in reality, it is difficult to realize it by increasing the number of processes, particularly by increasing costs.

  Therefore, Patent Document 1 discloses a system for identifying a defect cause process in a semiconductor manufacturing process. A defect cause identifying system according to Patent Document 1 includes a characteristic map forming unit that forms a characteristic map that represents an in-plane distribution of electrical characteristics of a semiconductor device inspected by an inspection device, and a plurality of semiconductor devices, and a measurement A single map forming unit that forms a single map that expresses the in-plane distribution of the performance of each process measured by the apparatus for each process, and a plurality of single maps are selected from the single maps for each process. Are combined to form a composite map, and a specific unit is provided that identifies the corresponding process as the cause of failure by comparing the composite map with the characteristic map.

  In particular, in the embodiment disclosed in Patent Document 1, it is preferable to measure the performance for each mesh obtained by dividing the wafer surface in chip units or shot units. It is disclosed that the performance of each mesh is generated using an interpolation method such as a bilinear plot or a simple arithmetic average based on the performance of several points or at most about 50 points. That is, in Patent Document 1, inspection object data in an inspection item is measured data in a sampled semiconductor device that is a part of a semiconductor device in a wafer, and data interpolated using the interpolation method with respect to the measurement data. Are used. Therefore, the inspection can be simplified as compared with the measurement for all the semiconductor devices in the wafer.

Non-Patent Document 1 discloses a thin plate spline as a curved surface model identifying process for interpolating measured data. Non-Patent Document 1 discloses a generalized cross validation (GCV) algorithm as a technique for removing an abnormal value of measured data. Further, Patent Document 2 discloses a so-called data thinning-out method for performing interpolation by reducing given data as a simplification of interpolation processing.
JP 2007-36068 A Japanese Patent No. 3881510 Grace Wahba, "Spline Models for Observational Data", Society for Industrial & Applied, 1990.

  However, the measurement data in the sampled semiconductor device has different measurement value variations, that is, the distribution tendency of the measurement values, for each inspection item. Moreover, the importance for each inspection item varies depending on the degree of influence on quality. Therefore, as in Patent Document 1 and Patent Document 2, there is a problem that the reliability of inspection target data for specifying the cause of a defect varies only by performing interpolation processing uniformly regardless of the inspection item or the substrate. is there. This problem occurs not only in the semiconductor element manufacturing process but also in the entire device manufacturing process in which a plurality of devices are manufactured on a substrate through a plurality of processes.

  In particular, with respect to measurement items with high importance, there may be a case where reliable data cannot be obtained due to data loss by uniform interpolation processing considering only simplification of interpolation processing. Further, even for items with small variations or items with low importance, performing the same interpolation processing uniformly may make the processing redundant. Therefore, in the same manufacturing process, it is necessary to determine the inspection position in consideration of measurement data on a plurality of substrates.

  In the present invention, in a device manufacturing process for manufacturing a plurality of devices in units of substrates, an inspection position determination method capable of determining an inspection position that reduces redundancy while maintaining reliability according to the characteristics of measurement data in an inspection item, An object is to provide an inspection information management system and an inspection method.

  The inspection position determination method according to the first aspect of the present invention is to determine an inspection position on a substrate corresponding to an inspection item in an inspection process performed in the process of manufacturing a device in units of substrates. A substrate model generation step for generating, for each substrate, a substrate model that is a data model for interpolating data at an arbitrary position on the substrate based on measurement data at a predetermined inspection candidate position on the substrate; A representative model generation step of generating a representative model that is the data model corresponding to the inspection item based on the substrate model of the measurement method, measurement data of the predetermined inspection candidate position, and interpolation data interpolated by the representative model And an inspection position determination step of determining an inspection position corresponding to data that can generate the representative model using at least one of them.

  Thereby, in a certain inspection item, it can be narrowed down as a representative model taking into account the tendency of measurement data from a plurality of substrates, while maintaining the reliability according to the characteristics of the measurement data in the inspection item using the representative model The inspection position that reduces redundancy can be determined. Therefore, effective measurement data can be acquired for each inspection item, and the efficiency of follow-up investigation at the time of abnormality is improved.

  Further, the representative model generation step selects at least a part of the measurement data of the predetermined inspection candidate position and the interpolation data interpolated by the substrate model of each substrate, and the selected data between the substrates is predetermined It is desirable to classify the substrates into groups by performing analysis and generate a representative model for each group.

  As a result, the substrate models with higher correlation can be made into one group, and by generating a representative model for each group, even if there are multiple data models in one inspection item, it is appropriate. A representative model can be generated.

  Furthermore, it is preferable that the inspection position determination step performs a predetermined calculation process for the selected data for each group, and generates a representative model using the data after the calculation process.

  Thereby, a representative model can be effectively generated in the classified group, and the reliability of the measurement data in the inspection item is improved.

  Further, the inspection position determination step selects at least a part of the measurement data of the predetermined inspection candidate position and the interpolation data interpolated by the representative model, and the reproduction model which is the data model based on the selected data When the reproduction model approximates the representative model, the inspection position corresponding to the selected data is preferably determined as the inspection position. Thereby, it is possible to narrow down the inspection positions necessary for reproducing the representative model.

  In the inspection position determination step, the inspection position may be determined including the inspection position determined for each group. As a result, the minimum required inspection position can be determined in consideration of a plurality of representative models, and the amount of measurement data saved can be reduced.

  The inspection position determining step may determine the inspection position based on a ratio of the number of substrates classified into the group. Thereby, it is possible to determine an appropriate inspection position in consideration of the ratio of the data model tendency in the inspection item, and it is possible to further improve the reliability of the measurement data.

  The substrate model generation step may generate the substrate model by excluding a predetermined abnormal value from measurement data at the predetermined measurement position. Thereby, the generation accuracy of the substrate model and the representative model is improved, and an appropriate inspection position can be determined. Therefore, the reliability of measurement data can be further improved.

  The inspection information management system according to the second aspect of the present invention manages information related to inspection items in the process of manufacturing devices in units of substrates. An inspection information storage unit that stores a predetermined inspection candidate position on the substrate that is predetermined for each inspection item, and measurement data that is measured at the inspection candidate position, and the substrate unit from the inspection information storage unit Measurement data is acquired, a substrate model that is a data model for interpolating data at an arbitrary position on the substrate is generated based on the measurement data, and the substrate model is stored in the inspection information storage unit. Obtaining a plurality of the substrate models from the substrate model generation unit and the inspection information storage unit, and generating a representative model that is the data model corresponding to the inspection item based on the plurality of the substrate models; A representative model generation unit for storing a model in the inspection information storage unit, measurement data of the predetermined inspection candidate position, and interpolation data interpolated by the representative model. Using at least one of data, to determine the inspection position corresponding to the data capable of generating the representative model, and a test position determining section for storing the inspection position to the inspection information storage unit.

  Thereby, in a certain inspection item, it can be narrowed down as a representative model taking into account the tendency of measurement data from a plurality of substrates, while maintaining the reliability according to the characteristics of the measurement data in the inspection item using the representative model The inspection position that reduces redundancy can be determined. Therefore, effective measurement data can be acquired for each inspection item, and the efficiency of follow-up investigation at the time of abnormality is improved.

  Further, the representative model generation unit selects at least a part of the measurement data of the predetermined inspection candidate position and the interpolation data interpolated by the substrate model of each substrate, and the selected data between the substrates is predetermined It is desirable to classify the substrates into groups by performing analysis, and to generate the data model in the group as the representative model.

  As a result, the substrate models with higher correlation can be made into one group, and by generating a representative model for each group, even if there are multiple data models in one inspection item, it is appropriate. A representative model can be generated.

  Furthermore, it is preferable that the representative model generation unit performs a predetermined calculation process on the selected data for each group, and generates a representative model using the data after the calculation process.

  Thereby, a representative model can be effectively generated in the classified group, and the reliability of the measurement data in the inspection item is improved.

  Further, the inspection position determination unit selects at least a part of the measurement data of the predetermined inspection candidate position and the interpolation data interpolated by the representative model, and the reproduction model which is the data model based on the selected data When the reproduction model approximates the representative model, the inspection candidate position of the selected data is stored in the inspection information storage unit as the inspection position. Thereby, it is possible to narrow down the inspection positions necessary for reproducing the representative model.

  The inspection position determination unit may determine an inspection position including an inspection position determined for each group. As a result, the minimum required inspection position can be determined in consideration of a plurality of representative models, and the amount of measurement data saved can be reduced.

  The inspection position information determination unit may store the inspection position information in the inspection information storage unit based on a ratio of the number of substrates classified into the group. Thereby, it is possible to determine an appropriate inspection position in consideration of the ratio of the data model tendency in the inspection item, and it is possible to further improve the reliability of the measurement data.

  The substrate model generation unit may generate the substrate model by excluding a predetermined abnormal value from measurement data in the predetermined measurement position information. Thereby, the generation accuracy of the substrate model and the representative model is improved, and an appropriate inspection position can be determined. Therefore, the reliability of measurement data can be further improved.

  The inspection method according to the third aspect of the present invention performs an inspection based on an inspection position on the substrate corresponding to an inspection item in an inspection process performed in the process of manufacturing a device in units of substrates. In order to interpolate data at an arbitrary position on the substrate based on a pre-measurement step for measuring the inspection item at a predetermined inspection candidate position on the substrate and measurement data measured by the pre-measurement step A board model that is a data model of the above is generated for each board, a representative model that is the data model corresponding to the inspection item is generated based on a plurality of the board models, and measurement data of the predetermined inspection candidate position And an inspection position determination step for determining an inspection position corresponding to data capable of generating the representative model using at least one of interpolation data interpolated by the representative model, and the inspection position determination in the process A manufacturing-time measurement step for measuring at the inspection position determined by the step, and the manufacturing-time measurement Based on the measurement data measured by the step, and a step of generating the substrate model. Thereby, effective measurement data according to the inspection position for each inspection item can be acquired, and the efficiency of the follow-up investigation at the time of abnormality is improved.

  According to the present invention, in a device manufacturing process for manufacturing a plurality of devices in units of substrates, an inspection position determination method capable of determining an inspection position for reducing redundancy while maintaining reliability according to the characteristics of measurement data in an inspection item, An inspection information management system and an inspection method can be provided.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted as necessary for the sake of clarity.

<Embodiment 1 of the Invention>
FIG. 1 is a block diagram showing an example of the configuration of an inspection information management system 100 according to the first embodiment of the present invention. The inspection information management system 100 manages information related to inspection items in a device manufacturing process for manufacturing a plurality of devices in units of substrates. Here, a semiconductor element is assumed as an example of the device. That is, the inspection information management system 100 is intended for a semiconductor manufacturing process in which a plurality of semiconductor elements are manufactured in units of silicon wafers (hereinafter referred to as wafers) that are substrates. The inspection information management system 100 determines an inspection position on the substrate corresponding to the inspection item in the semiconductor manufacturing process described above, and performs an inspection based on the inspection position. In addition, the device concerning this invention is not limited to this, Industrial products, such as a flat panel and a solar cell, may be sufficient. Therefore, this invention is applicable also about manufacture inspection of industrial products, such as a flat panel and a solar cell. The inspection information management system 100 may select a specific device from a plurality of devices on the substrate and determine the device as an inspection position. Further, the inspection information management system 100 may include one or a plurality of devices on a substrate, a plurality of inspection candidate positions on the device, and determining an inspection position from the plurality of inspection candidate positions.

  The inspection information management system 100 in FIG. 1 includes a production line 1, a measuring device 2, an inspection device 3, an inspection support device 4, an inspection information storage device 5, and a communication line 6. The manufacturing line 1 includes manufacturing apparatuses 1a, 1b,..., And 1n used in each manufacturing process for manufacturing a plurality of semiconductor elements on a wafer. Here, the manufacturing process includes, for example, oxide film diffusion, etching, ion implantation, sputtering, and cleaning.

  In addition, the manufacturing apparatuses 1 a, 1 b,..., And 1 n, the measuring apparatus 2, the inspection apparatus 3, the inspection support apparatus 4, and the inspection information storage apparatus 5 are connected via a communication line 6. The communication line 6 may be a communication network such as the Internet, a public network, a dedicated line, and a mobile communication network.

  The inspection information storage device 5 is a storage device that stores inspection items 51, measurement positions 52, measurement data 53, substrate models 54, representative models 55, and inspection positions 56. The inspection information storage device 5 may be a nonvolatile storage device such as a hard disk drive or a flash memory, or may be a volatile storage device such as a DRAM (Dynamic Random Access Memory).

  The inspection item 51 is information indicating inspection items such as width, thickness, resistance, conductivity, and the like for the wafer in each manufacturing process. A plurality of inspection items 51 may exist in one manufacturing process, and one inspection item 51 may be used when inspecting a plurality of manufacturing steps.

  The measurement position 52 is information indicating the position of the semiconductor element on the wafer, and here is two-dimensional coordinate information. The measurement position 52 according to the first embodiment of the present invention indicates an initial sampling location on the wafer in the inspection position determination process described later. The measurement position 52 is a predetermined inspection candidate position on the substrate.

The measurement data 53 is data measured for the measurement position 52 on the measurement target wafer for each inspection item 51 by the measurement apparatus 2 described later. The measurement data 53 is associated with the inspection item 51 and the wafer and exists for each measurement position 52. The measurement data 53 is, for example, shape data when the inspection item 51 is width or thickness or the like, and is electrical characteristic data when the inspection item 51 is resistance or conductivity, or is not limited thereto.

  The substrate model 54 is a data model for interpolating data at an arbitrary position on the substrate. The substrate model 54 is generated by the inspection support apparatus 4 described later based on the measurement data 53 measured for each wafer.

  Here, the data model in the present invention is represented by an N-dimensional curved surface model that approximates the relationship between N (N is an integer of 2 or more) types of variables. For example, when the measurement position 52 is two-dimensional coordinate information, it can be represented by a two-dimensional function expression. However, the substrate model 54 is not limited to a curved surface model, and may be a curved line or other models. The substrate model 54 can interpolate values at arbitrary positions other than the measurement position 52 on the wafer. Therefore, the measuring apparatus 2 does not need to measure all the semiconductor elements on the wafer.

  The representative model 55 is a data model in the inspection item 51. At least one representative model 55 is generated by the inspection support apparatus 4 in the inspection item 51.

  The inspection position 56 is information indicating the position of the semiconductor element on the wafer, like the measurement position 52. The inspection position 56 is a position determined by the inspection support device 4.

  The measuring device 2 performs measurement related to the inspection item 51 for a plurality of wafers manufactured in each manufacturing process using the manufacturing devices 1a, 1b,. In the measurement, the measurement device 2 measures the measurement position 52 in each wafer, and stores the measured data as the measurement position 52 in the inspection information storage device 5 in association with the inspection item 51 and the wafer.

  The inspection support apparatus 4 executes an inspection position determination process for determining an inspection position 56 on the wafer corresponding to the inspection item 51. The inspection support apparatus 4 functions as a board model generation unit 41, a representative model generation unit 42, and an inspection position determination unit 43. Further, the inspection support apparatus 4 can instruct the measurement apparatus 2 to perform measurement based on the measurement position 52 in the inspection position determination process.

  For each inspection item 51, the substrate model generation unit 41 acquires measurement data 53 for each wafer from the inspection information storage device 5, generates a substrate model 54 for the wafer based on the measurement data 53, and generates the substrate model 54. Store in the inspection information storage device 5.

  The representative model generation unit 42 acquires all the board models 54 in the inspection item 51 from the inspection information storage device 5, generates a representative model 55 corresponding to the inspection item 51 based on the acquired board model 54, and represents the representative model. 55 is stored in the examination information storage device 5.

  The inspection position determination unit 43 sets the measurement position 52 corresponding to the interpolation data that can generate the representative model 55 among the interpolation data interpolated by the representative model 55 at the measurement position 52 to the inspection position 56 corresponding to the inspection item 51. Is stored in the inspection information storage device 5. The inspection position determination unit 43 can generate the representative model 55 using at least one of the measurement data 53 of the measurement position 52 that is a predetermined inspection candidate position and the interpolation data interpolated by the representative model 55. The inspection position 56 corresponding to the data may be determined. That is, the inspection position determination unit 43 may not use the measurement data 53. In that case, the inspection position 56 may be determined at a position other than the measurement position 52.

  Thereby, in a certain inspection item, it can be narrowed down as a representative model taking into account the tendency of measurement data from a plurality of substrates, while maintaining the reliability according to the characteristics of the measurement data in the inspection item using the representative model The inspection position that reduces redundancy can be determined. Therefore, effective measurement data can be acquired for each inspection item, and the efficiency of follow-up investigation at the time of abnormality is improved.

  In particular, the representative model generation unit 42 selects the wafer based on the correlation between the interpolation data interpolated by the substrate model 54 in the wafer at the measurement position 52 and the interpolation data at the measurement position 52 in another wafer different from the wafer. The data model in the group is generated as a representative model 55.

  As a result, the substrate models with higher correlation can be made into one group, and by generating a representative model for each group, even if there are multiple data models in one inspection item, it is appropriate. A representative model can be generated.

  In addition, when the representative model generation unit 42 generates a plurality of representative models 55 for a certain inspection item 51, the inspection position determination unit 43 determines that the interpolation data interpolated by each of the plurality of representative models 55 represents the representative model 55. When the interpolation data can be generated, the measurement position 52 corresponding to the interpolation data is stored in the inspection information storage device 5 as the inspection position 56.

  Thereby, even when there are a plurality of data models in one inspection item, it is possible to narrow down an appropriate inspection position in consideration of each data model. Therefore, the reliability of the measurement data in the inspection item is improved.

  Further, the inspection position determination unit 43 stores the measurement position 52 corresponding to the smallest interpolation data among the interpolation data that can generate the representative model 55 as the inspection position 56 in the inspection information storage device 5. Thereby, the minimum necessary inspection position can be determined, and the storage amount of measurement data can be reduced.

  Further, the measuring device 2 performs measurement at the inspection position 56 determined by the inspection support device 4 in the device manufacturing process, and stores the measurement data 53 in the inspection information storage device 5.

  The inspection apparatus 3 inspects all semiconductor elements on all wafers at the end of the device manufacturing process in the manufacturing line 1. When there is a semiconductor element determined to be abnormal in the inspection, the inspection apparatus 3 notifies the inspection support apparatus 4 to activate the substrate model generation unit 41 in the inspection support apparatus 4. Then, the inspection support apparatus 4 generates a substrate model 54 relating to the wafer including the semiconductor element determined to be abnormal. As a result, the value at an arbitrary position other than the inspection position 56 on the wafer can be interpolated, and therefore the investigation of the cause of the abnormality can be supported by providing the interpolation data.

  FIG. 2 is a block diagram showing a configuration of the examination support apparatus 4 according to the first embodiment of the present invention. The inspection support apparatus 4 is a general-purpose computer system, and includes a CPU (Central Processing Unit) 411, a RAM (Random Access Memory) 412, a ROM (Read Only Memory) 413, a communication unit 414, and a hard disk 420. Prepare. The hard disk 420 is a non-volatile storage device, and stores an OS (Operating System) 421 and an inspection position determination program 422 for performing inspection position determination processing. The CPU 411 controls various processes in the inspection support apparatus 4, that is, processes of various programs, access to the RAM 412, ROM 413, the communication unit 414, and the hard disk 420. The communication unit 414 accesses the inspection information storage device 5 through the communication line 6, and transmits and receives various data including the inspection item 51, measurement position 52, measurement data 53, substrate model 54, representative model 55, and inspection position 56. And so on.

  In the inspection support apparatus 4, the CPU 411 reads and executes the OS 421 and the inspection position determination program 422 stored in the RAM 412, the ROM 413, or the hard disk 420. Thereby, the test | inspection assistance apparatus 4 can perform a test | inspection position determination process.

  Subsequently, an inspection position determination process according to the first embodiment of the present invention is shown in a flowchart of FIG. In the following description, the process of identifying a curved surface model refers to the process of generating the above-described substrate model and a data model that is a representative model. In the embodiment of the present invention, the curved surface model is identified. However, it goes without saying that the same method can be applied to the identification of the curved model.

  Here, in order to clarify the effect of the invention, an example in which the inspection position determination process is applied to simulation data will be described. It is assumed that the inspection item 51 and the measurement position 52 are stored in the inspection information storage device 5 as initial values. FIG. 4 is a diagram illustrating an example of the measurement position 52. In FIG. 4, the measurement positions 52 are 21 positions. However, the present invention is not limited to this. For example, all the semiconductor element positions may be the measurement positions 52.

  Further, it is assumed that a plurality of wafers have already been manufactured in order to determine the inspection position in an arbitrary manufacturing apparatus of the manufacturing line 1. In the following example, the number of wafers is 40. However, the number of wafers is not limited to this, and it may be at least 2 or more. By determining the inspection position from a plurality of wafers, it is possible to acquire measurement data that takes into account the characteristics of the inspection items, and improve the reliability of the inspection.

  First, the inspection support apparatus 4 performs measurement related to the inspection item 51 at a predetermined measurement position 52 on the wafer by the measurement apparatus 2 (S101). Specifically, the examination support apparatus 4 acquires the examination item 51 and the measurement position 52 from the examination information storage device 5 and performs measurement based on the examination item 51 and the measurement position 52 with respect to the measurement apparatus 2. Give instructions. Then, the measuring device 2 performs measurement on the position shown in FIG. 4 on the wafer described above based on the inspection item 51 and stores the measurement data 53 in the inspection information storage device 5. Here, as an example, it is assumed that measurement data as shown in FIG. 5 is measured.

  Next, the inspection support apparatus 4 identifies the substrate model 54 for each wafer (S102). Specifically, the board model generation unit 41 of the inspection support apparatus 4 acquires the measurement data 53 associated with the inspection item 51 from the inspection information storage device 5 and thin plate splines as shown in Non-Patent Document 1 for each wafer. Is used to identify a curved surface model. The method for identifying the curved surface model is not limited to the thin plate spline. Here, as an example, a curved surface model of four wafers is shown by contour lines in FIG.

  Subsequently, the inspection support apparatus 4 classifies the plurality of substrate models 54 into groups according to the patterns (S103). Specifically, the representative model generation unit 42 of the inspection support apparatus 4 acquires the substrate model 54 from the inspection information storage device 5 and calculates interpolation data at the measurement position 52 by the substrate model 54. Then, the representative model generation unit 42 classifies the wafers into groups based on the correlation between the interpolation data for a certain wafer and the interpolation data for another wafer. Here, the representative model generation unit 42 selects at least part of the interpolation data interpolated by the measurement data 53 and the board model 54 of each board, and performs a predetermined analysis on the selected data between the boards. The substrates may be classified into groups, and a representative model 55 may be generated for each group. The predetermined analysis may be, for example, cluster analysis, CART or k-mean algorithm.

  FIG. 7 is a diagram illustrating an example in which a plurality of substrate models in the inspection item 51 are classified by cluster analysis. Here, according to the threshold value of the classification of the substrate model 54, the 40 wafers are classified into two groups of pattern 1 and pattern 2, respectively. In the embodiment of the present invention, the substrate model 54 may be classified into at least one group.

  And the test | inspection assistance apparatus 4 identifies the representative model 55 for every classified group (S104). For example, the representative model generation unit 42 of the inspection support apparatus 4 first averages the measurement data 53 of the wafers belonging to the pattern 1 for each measurement position 52. Then, the representative model generation unit 42 identifies a curved surface model from the averaged data using a thin plate spline. FIG. 8 is a diagram illustrating an example of a representative model in the pattern 1. Similarly, the representative model generation unit 42 identifies a curved surface model for the pattern 2. FIG. 9 is a diagram illustrating an example of a representative model in the pattern 2. The representative model generation unit 42 may perform a predetermined calculation process for each group on the data selected at the time of classification, and generate a representative model using the data after the calculation process. Here, the predetermined calculation process is not limited to the average, and may be a median, an intermediate value, only a minimum, only a maximum, or the like.

  Thereafter, the inspection support apparatus 4 determines inspection positions 56 necessary for reproducing all the representative models 55 (S105). Specifically, first, the inspection position determination unit 43 of the inspection support apparatus 4 selects at least a part of the measurement positions 52. Next, the inspection position determination unit 43 generates a reproduction model that is a data model based on the interpolation data corresponding to the selected measurement position among the interpolation data at the measurement position 52 interpolated by the representative model 55. Then, the inspection position determination unit 43 stores the selected measurement position as the inspection position 56 in the inspection information storage device 5 when the reproduction model approximates the representative model. Thereby, it is possible to narrow down the inspection positions necessary for reproducing the representative model.

  Furthermore, when the reproduction model approximates the representative model, the inspection position determination unit 43 repeats identifying a reproduction model by further reducing a part of the measurement position 52, thereby obtaining the least amount of interpolation data. It is good to specify. Thereby, the inspection support apparatus 4 can determine the minimum inspection position 56 necessary for reproducing all the representative models 55.

  For example, first, the inspection position determination unit 43 selects 20 positions from among 21 measurement positions 52 excluding one place. Next, the inspection position determination unit 43 identifies a reproduction model based on the measurement data 53 corresponding to the 20 locations. Then, in step S104, an absolute error between the averaged data for the pattern 1 and the interpolation data interpolated at 21 positions that are the measurement positions 52 by the reproduction model is calculated. The inspection position determination unit 43 also calculates such an absolute error from the measurement positions 52 excluding the other one of the 21 measurement positions 52, and for the smallest absolute error, the absolute error is a predetermined value. It is determined whether or not the threshold value is exceeded. If the predetermined threshold is not exceeded, the absolute error is calculated in the same manner except for one place from the 20 places except for the one place, and the process is performed until the predetermined threshold is exceeded. Then, the inspection position determination unit 43 determines the measurement position immediately before exceeding the predetermined threshold as the inspection position 56.

  The inspection position determination unit 43 selects at least part of the interpolation data interpolated by the measurement data 53 and the representative model 55, generates a reproduction model that is a data model based on the selected data, and generates the reproduction model. Is approximate to the representative model 55, the inspection position corresponding to the selected data may be determined as the inspection position 56. Here, the approximation described above is not limited to the case where the absolute error is within a predetermined threshold, and a relative error or the like may be used.

  Alternatively, the number of inspection positions of the inspection position may be determined first, and the inspection position may be determined so as to minimize the absolute error or the like from any combination of the number of inspection positions.

  In order to narrow down the portions necessary for reproducing such a curved surface model, for example, a data thinning method disclosed in Patent Document 2 may be employed.

  When a plurality of representative models 55 are generated in step S104, for example, when two curved models of pattern 1 and pattern 2 are identified, the inspection position determination unit 43 calculates an absolute error from each pattern. However, it is only necessary to adopt the one having the smallest absolute error. That is, when the interpolation data interpolated by each of the plurality of representative models 55 is interpolation data that can generate each representative model, the inspection position determination unit 43 determines the measurement position corresponding to the interpolation data. The inspection position 56 is determined.

  In the example according to the first embodiment of the present invention, the above-described absolute error threshold is set to 0.01, and the measurement positions necessary for reproducing the representative model 55 in the pattern 1 and the pattern 2 can be narrowed down from 21 to 14 locations. did it. FIG. 10 is a diagram illustrating an example of inspection positions where a representative model in the pattern 1 can be generated. FIG. 11 is a diagram illustrating an example of inspection positions where a representative model in the pattern 2 can be generated. FIG. 12 is a diagram illustrating an example of the inspection position determined by the inspection position determination process according to the first embodiment of the present invention.

  As described above, according to the first embodiment of the present invention, in the device manufacturing process for manufacturing a plurality of devices in units of substrates, the inspection reduces the redundancy while maintaining the reliability according to the characteristics of the measurement data in the inspection item. The position can be determined.

  In step S103, the classification threshold may be arbitrarily changed. By lowering the classification threshold, the number of groups to be classified relatively increases. However, the substrate model 54 having a high correlation belongs to each group, and the accuracy of the representative model 55 is increased. Further, by increasing the classification threshold, the number of groups to be classified is relatively reduced, but by reducing the representative model 55, the processing load in step S105 is reduced, and the efficiency of the inspection position determination process itself is increased.

  Next, an inspection process using the inspection position 56 determined by the inspection position determination process will be described. FIG. 13 is a flowchart showing the inspection process according to the first embodiment of the present invention. First, the measuring device 2 performs measurement at the inspection position 56 determined in step S105 in the device manufacturing process (S201). Then, the measuring device 2 measures the inspection position 56 on the manufactured wafer based on the inspection item 51 and stores the measurement data 53 in the inspection information storage device 5. At this time, the measurement apparatus 2 may be executed by an instruction from the inspection support apparatus 4 as in step S101. However, the inspection support device 4 instructs the inspection position 56.

  Next, the inspection support apparatus 4 identifies the substrate model 54 for each wafer as in step S102 (S202). Thereby, effective measurement data according to the inspection position for each inspection item can be acquired, and the efficiency of the follow-up investigation at the time of abnormality is improved.

  Note that step S201 can be performed more accurately by executing it every time a wafer is manufactured. Further, when there is a semiconductor element determined to be abnormal in the inspection by the inspection apparatus 3, step S202 may be executed only on the wafer including the semiconductor element.

  In the semiconductor manufacturing process, the manufacturing apparatus used in each manufacturing process is designed with the goal of obtaining precise reproducibility. Therefore, it can be said that one or more specific limited patterns are reproduced also for the data model derived from the data group measured in the manufacturing process. Therefore, in each manufacturing process, the derived data path model is classified into a limited one, and when narrowing down the measurement position for each pattern, the relationship with the data model in other patterns is taken into account. It is possible to narrow down the inspection position according to.

<Other embodiments of the invention>
The embodiment of the present invention is applied to a plurality of inspection items in a plurality of manufacturing processes, thereby reducing redundancy while maintaining reliability according to the characteristics of measurement data in the inspection items or manufacturing processes. The inspection position to be determined can be determined.

  The representative model generation unit 42 may generate the substrate model by excluding predetermined abnormal values from the measurement data 53 at the measurement position 52. Thereby, the generation accuracy of the substrate model and the representative model is improved, and an appropriate inspection position can be determined. Therefore, the reliability of measurement data can be further improved.

  When a thin plate spline is used for the identification process of the curved surface model, for example, measurement data 53 that causes a large error is measured using a GCV (Generalized Cross Validation) algorithm disclosed in Non-Patent Document 1. The position 52 can be specified. Note that the abnormal value removal method is not limited to the GCV algorithm.

  Further, the inspection position determination unit 43 calculates the absolute error for each pattern in step S105 based on the sum ratio based on the ratio of the number of wafers classified into groups, determines the inspection position 56, and the inspection information storage device 5 It is good to store in. Thereby, it is possible to determine an appropriate inspection position in consideration of the ratio of the data model tendency in the inspection item, and it is possible to further improve the reliability of the measurement data.

  Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention described above.

It is a block diagram which shows an example of a structure of the test | inspection information management system concerning Embodiment 1 of this invention. It is a block diagram which shows the structure of the test | inspection assistance apparatus concerning Embodiment 1 of this invention. It is a flowchart figure which shows the test | inspection position determination process concerning Embodiment 1 of this invention. It is a figure which shows the example of a measurement position. It is a figure which shows the example of measurement data. It is a figure which shows the example of a board | substrate model. It is a figure which shows the example of a classification | category of a board | substrate model. It is a figure which shows the example of a representative model. It is a figure which shows the example of a representative model. It is a figure which shows the example of the test | inspection position which can produce | generate a representative model. It is a figure which shows the example of the test | inspection position which can produce | generate a representative model. It is a figure which shows the example of the test | inspection position determined by the test | inspection position determination process concerning Embodiment 1 of this invention. It is a flowchart figure which shows the test | inspection process concerning Embodiment 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Inspection information management system 1 Manufacturing line 1a Manufacturing apparatus 1b Manufacturing apparatus 1n Manufacturing apparatus 2 Measuring apparatus 3 Inspection apparatus 4 Inspection support apparatus 41 Board | substrate model generation part 42 Representative model generation part 43 Inspection position determination part 5 Inspection information storage apparatus 51 Inspection item 52 Measurement position 53 Measurement data 54 Substrate model 55 Representative model 56 Inspection position 6 Communication line 411 CPU
412 RAM
413 ROM
414 Communication unit 420 Hard disk 421 OS
422 Inspection position determination program

Claims (15)

An inspection position determination method for determining an inspection position on a substrate corresponding to an inspection item in an inspection process performed in a process of manufacturing a device in units of substrates,
A board model generation step for generating, for each board, a board model that is a data model for interpolating data at an arbitrary position on the board based on measurement data at a predetermined inspection candidate position on the board;
A representative model generation step of generating a representative model that is the data model corresponding to the inspection item based on a plurality of the substrate models;
An inspection position determining step for determining an inspection position corresponding to data capable of generating the representative model using at least one of the measurement data of the predetermined inspection candidate position and the interpolation data interpolated by the representative model; ,
An inspection position determination method comprising:   The representative model generation step selects at least a part of the measurement data of the predetermined inspection candidate position and the interpolation data interpolated by the substrate model of each substrate, and performs a predetermined analysis on the selected data between the substrates. 2. The inspection position determination method according to claim 1, wherein the substrate is classified into groups by performing, and a representative model is generated for each group.   The inspection according to claim 2, wherein the representative model generation step performs a predetermined calculation process for the selected data for each group, and generates a representative model using the data after the calculation process. Positioning method. The inspection position determining step includes:
Select at least part of the measurement data of the predetermined inspection candidate position and interpolation data interpolated by the representative model, and generate a reproduction model that is the data model based on the selected data,
When the reproduction model approximates the representative model, the inspection position corresponding to the selected data is determined as the inspection position.
The inspection position determination method according to claim 1, wherein the inspection position is determined. The inspection position determination step determines an inspection position including an inspection position determined for each group.
The inspection position determination method according to any one of claims 2 and 3, or claim 4 subordinate to claim 2 or 3.   The inspection position determination step determines the inspection position based on a ratio of the number of substrates classified into the group by the representative model generation step. 5. The inspection position determination method according to claim 4, which is dependent on 3.   The said board | substrate model production | generation step excludes a predetermined abnormal value from the measurement data in the said predetermined measurement position, and produces | generates the said board | substrate model, The any one of Claim 1 thru | or 6 characterized by the above-mentioned. Inspection position determination method. An inspection information management system that manages information related to inspection items in the process of manufacturing devices in units of substrates,
A test information storage unit for storing a predetermined test candidate position on the substrate predetermined for each test item, and measurement data measured at the test candidate position;
Measurement data is acquired for each substrate from the inspection information storage unit, and a substrate model that is a data model for interpolating data at an arbitrary position on the substrate is generated based on the measurement data, and the substrate model A board model generation unit for storing the inspection information storage unit,
Obtaining a plurality of the substrate models from the inspection information storage unit, generating a representative model that is the data model corresponding to the inspection item based on the plurality of substrate models, and storing the representative model in the inspection information storage Representative model generation unit to be stored in the unit,
Using at least one of measurement data of the predetermined inspection candidate position and interpolation data interpolated by the representative model, an inspection position corresponding to data that can generate the representative model is determined, and the inspection position is determined. An inspection information management system comprising: an inspection position determination unit that is stored in the inspection information storage unit.   The representative model generation unit selects at least a part of the measurement data of the predetermined inspection candidate position and interpolation data interpolated by the substrate model of each substrate, and performs a predetermined analysis on the selected data between the substrates. 9. The inspection information management system according to claim 8, wherein the board is classified into a group by performing, and the data model in the group is generated as the representative model.   The inspection according to claim 9, wherein the representative model generation unit performs a predetermined calculation process for the selected data for each group, and generates a representative model using the data after the calculation process. Information management system. The inspection position determination unit
Select at least part of the measurement data of the predetermined inspection candidate position and interpolation data interpolated by the representative model, and generate a reproduction model that is the data model based on the selected data,
If the reproduction model approximates the representative model, the inspection candidate position of the selected data is stored in the inspection information storage unit as the inspection position.
The inspection information management system according to any one of claims 8 to 10.   The inspection position determination unit determines an inspection position including an inspection position determined for each group, or any one of claims 11 and 11 dependent on claim 9 or 10. Inspection information management system described in the section.   The inspection position information determination unit stores the inspection position information in the inspection information storage unit based on a ratio of the number of substrates classified into the group by the representative model generation step. The inspection information management system according to claim 9, which is dependent on claim 9 or 10 or claim 9 or claim 10.   The said board | substrate model production | generation part excludes a predetermined abnormal value from the measurement data in the said predetermined measurement position information, and produces | generates the said board | substrate model, The any one of Claim 8 thru | or 13 characterized by the above-mentioned. Inspection information management system described. In the inspection process performed in the process of manufacturing a device with the substrate unit, have lines for inspection based on inspection position on the substrate corresponding to the test item, a inspection support method for supporting research abnormality cause,
A pre-measuring step for measuring the inspection item at a predetermined inspection candidate position on the substrate;
Based on the measurement data measured in the preliminary measurement step, a first substrate model that is a data model for interpolating data at an arbitrary position on the substrate is generated for each substrate, and a plurality of the first models are generated . Based on one substrate model, a representative model that is the data model corresponding to the inspection item is generated, and at least one of measurement data of the predetermined inspection candidate position and interpolation data interpolated by the representative model is used. An inspection position determining step for determining an inspection position corresponding to data capable of generating the representative model;
Each time the substrate is being manufactured, the manufacturing time measuring step of performing measurements related to the inspection items have you at the test position determined by the inspection position determining step for the substrate that is the production,
A determination step for determining whether or not there is an abnormality in a device included in the manufactured substrate, based on the measurement data measured in the manufacturing measurement step;
When there is a device determined to be abnormal in the determination step , generating a second substrate model related to the substrate including the device determined to be abnormal based on the measurement data measured in the measurement step during manufacture; ,
Outputting interpolated data interpolated by the second substrate model for investigating the cause of the abnormality;
An inspection support method comprising:

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