Determining the location of suspected defects

Abstract

To provide determination of locations of suspected defects.SOLUTION: The present invention provides a method, a non-transitory computer readable medium and a detection system for determining locations of suspected defects of a substrate.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application No. 16 / 808,111, filed March 3, 2020, the disclosure of which is incorporated herein by reference in its entirety for all purposes. [Background technology]

[0002] Wafers, such as semiconductor wafers, are subjected to many mechanical and chemical processes that can result in various types of defects.

[0003] Wafer inspection and review is performed in two stages: During the first stage, an optical wafer inspection system locates suspected defects and generates location information regarding the locations of the suspected defects.

[0004] During the second stage, a charged particle review system (such as a scanning electron microscope) reviews the suspected defects and determines which of the suspected defects are actual defects.

[0005] Optical wafer inspection systems are much faster than charged particle review systems and can scan an entire wafer in a relatively short period of time. The resolution of charged particle review systems is much finer than that of optical wafer inspection systems, allowing them to review nanometer-scale defects. Thus, two-stage wafer inspection and review offers a trade-off between speed and accuracy.

[0006] The optical wafer inspection system and the charged particle review system differ from one another in that a wafer inspected by the optical wafer inspection system is mechanically transferred to the charged particle review system. Summary of the Invention [Problem to be solved by the invention]

[0007] For a variety of reasons, the charged particle review system may not be able to assume that the suspected defects are located exactly at the locations indicated in the position information of the suspected defects as measured by the optical wafer inspection system, which may include inaccuracies in the charged particle review system's position measurements, inaccuracies in the navigation of the charged particle review system, and misalignment between the charged particle review system and the optical wafer inspection system.

[0008] Therefore, charged particle review systems must search for suspected defects within a relatively large search window centered around the location of the suspected defect.

[0009] The discovery process takes time.

[0010] There is an increasing need to provide a more accurate search process. [Means for solving the problem]

[0011] A method, non-transitory computer readable medium, and system for determining a location of a suspected defect may be provided.

[0012] The subject matter which is regarded as embodiments of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, the embodiments of the present disclosure, both as to organization and method of operation, together with its objects, features, and advantages, will best be understood by reference to the following detailed description when read in connection with the accompanying drawings. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 illustrates an example of a method. [Diagram 2] FIG. 1 is a diagram showing an example of division of a wafer into five regions. [Diagram 3] FIG. 1 shows an example of a linear estimation law selected by calculating the least squared error. [Figure 4]FIG. 13 illustrates an example of a distribution of multiple estimated CPRS fix positions, a histogram, and a matched filter function. [Diagram 5] FIG. 1 illustrates an example of a method. [Figure 6] FIG. 1 illustrates an example of a system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present disclosure.

[0015] However, it will be understood by those skilled in the art that the present embodiment of the disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present embodiment of the disclosure.

[0016] The subject matter which is regarded as embodiments of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, the embodiments of the present disclosure, both as to organization and method of operation, together with its objects, features, and advantages, will best be understood by reference to the following detailed description when read in connection with the accompanying drawings.

[0017] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

[0018] Because the illustrative embodiments of the present disclosure can be implemented, for the most part, using electronic components and circuits known to those skilled in the art, no more detail will be described than is deemed necessary, as previously described, for an understanding and appreciation of the basic concepts of the present embodiment of the present disclosure, and in order not to obscure or distract from the teachings of the present embodiment of the present disclosure.

[0019] Any reference in this specification to a method should be applied mutatis mutandis to a system capable of carrying out the method, and should be applied mutatis mutandis to a computer readable medium that is non-transient and stores instructions for carrying out the method.

[0020] Any reference in this specification to a system should be applied mutatis mutandis to methods that may be carried out by the system, and should be applied mutatis mutandis to a computer readable medium that is non-transient and stores instructions executable by the system.

[0021] Any reference in this specification to a computer readable medium being non-transitory should be applied mutatis mutandis to the manner in which it may be applied when executing instructions stored on the computer readable medium, and should be applied mutatis mutandis to a system configured to execute instructions stored on the computer readable medium.

[0022] The term "and / or" means additionally or alternatively.

[0023] The terms "comprising," "having," "consisting," and "consisting essentially of" are used interchangeably. Any reference to one of a term is applicable mutatis mutandis to any other of a term.

[0024] The term "configured" can mean "constructed and arranged" and / or programmed.

[0025] The following terms are used herein: o Optical Wafer Inspection System (OWIS) - A wafer inspection system that uses light to detect defects. An OWIS can illuminate the wafer with visible, ultraviolet, deep ultraviolet, and extreme ultraviolet radiation. Non-limiting examples of an OWIS include the UVision™ family manufactured by Applied Materials Inc. of California, USA. o OWIS Determined Location of Suspected Defect – The location (e.g., coordinates) of the suspected defect as measured by OWIS. o Charged Particle Review System (CPRS) - A charged particle review system that uses charged particle radiation to review defects. A CPRS can illuminate the suspected defect and its vicinity with an electron beam or an ion beam. Non-limiting examples of a CPRS include the SEM-Vision™ family manufactured by Applied Materials Inc. of California, USA. o CPRS determined location of suspected defect – the location (e.g., coordinates) of the suspected defect as measured by the CPRS. o permutation related mapping - a mapping between (a) the OWIS decision positions of suspected defects belonging to a subgroup of suspected defects forming a permutation, and (b) the CPRS decision positions of suspected defects belonging to the subgroup.

[0026] FIG. 1 illustrates an example of a method 100.

[0027] Method 100 may begin by receiving OWIS determined locations of suspected defects on a wafer, step 110. The OWIS determined locations of suspected defects on a wafer may be received by a CPRS.

[0028] The OWIS determined locations of suspected defects on a wafer can be provided in a variety of formats, for example, a map of the suspected defects.

[0029] The suspected defects may extend across the entire wafer or over only a portion of the wafer.

[0030] Step 110 may be followed by step 120 of reviewing a number of suspected defects.

[0031] A number of suspected defects may be located within one or more areas of the wafer.

[0032] 2 shows the division of wafer 10 into five regions: first region 201, second region 202, third region 203, fourth region 204, and fifth region 205. First region 201 is a circle in the center of wafer 10. The other regions are segments of annular portions of the wafer that surround the first region.

[0033] The regions may differ in shape and size from those in FIG.

[0034] Referring back to FIG. 1 , the review may include searching for a number of suspected defects in an initial search window. The initial search window may be defined to include the suspected defects. The initial search window may be defined based on OWIS determined locations of the group of suspected defects. The initial search window may be a portion of an area of ​​the wafer.

[0035] Step 120 may be followed by a step 130 of filtering the number of suspected defects to select, based on one or more selection criteria, suspected defects that form a group of suspected defects.

[0036] Filtering may include rejecting suspected defects that are outside a particular size range, and rejecting suspected defects that border the initial search window and may extend outside the initial search window.

[0037] Additionally, in another example, filtering suspect defects based on a ratio between the highest and second highest automatic defect detection (ADR) scores.

[0038] The suspected defects in the group are only a portion of the suspected defects in the substrate.

[0039] The size of the groups (the number of suspected defects per group) can be determined in a variety of ways, for example, the size may be set based on the success or failure of previous attempts to find suspected defects, etc.

[0040] At the end of step 130, the group of suspected defects and the CPRS determined locations of the group of suspected defects are known. Table 1 shows an example of the result of step 130. [Table 1] Table 1

[0041] The group of suspected defects is assumed to include a first number (Ng) of suspected defects, where Ng is a positive integer greater than one.

[0042] Method 100 may include searching for a predefined number of suspected defects that pass the filter in one area of ​​the wafer, and then searching for the next suspected defects that pass the filter in another area of ​​the wafer.

[0043] Step 130 may be followed by step 140 of defining multiple permutations of the suspected defects, each permutation of the suspected defects being formed by a subgroup of the group of suspected defects.

[0044] Each subgroup includes a second number (Ns) of suspected defects, Ns being less than Ng.

[0045] Step 140 may include defining all possible permutations of the suspected defects, for example, given a group of size Ng, all possible permutations of size Ns.

[0046] Step 140 may be followed by step 150 of computing a permutation association mapping for each permutation of the suspected defect (among multiple permutations of the suspected defect).

[0047] The result of step 150 is a number of permutation relational mappings.

[0048] Each permutation association mapping maps (a) a CPRS-determined location of a suspected defect of a permutation to (b) an OWIS-determined location of a suspected defect of a permutation, where each permutation of a suspected defect is formed by a subgroup of the group of suspected defects.

[0049] The calculation can be done in various ways, for example by linear extrapolation.

[0050] All displacement mappings can take into account one or more sources of positional error, such as XY offset, scaling, and rotation.

[0051] FIG. 3 shows an example of a linear estimation law selected by calculating the least squares error.

[0052] The permutation relation mapping matrix 283 multiplied by the OWIS coordinate matrix 282 is equal to the CPRS coordinate matrix 281 .

[0053] In FIG. 3, the permutation relation mapping matrix 283 includes three pairs of coefficients (A0, B0, A1, B1, A2, B2) that represent three different sources of position error, e.g., XY offset, scaling, and rotation.

[0054] A simpler permutation related mapping, for example one that represents only XY offsets, would involve a vector containing only one pair of coefficients (eg, a vector containing elements A0, B0, and zero).

[0055] Referring back to FIG. 1, step 150 may be followed by step 160 of selecting the selected permutation related mapping.

[0056] Step 160 may include steps 162 and 168 .

[0057] Step 162 may include calculating a score for each of a number of permutation association mappings to provide a number of scores.

[0058] Step 168 may include selecting the selected replacement based on a number of scores.

[0059] Step 162 may include steps 164 and 166 .

[0060] Step 164 may include applying each of the multiple permutation association mappings to the OWIS decision locations of the group of suspect defects to provide an estimated multiple CPRS decision locations of the group of suspect defects.

[0061] Step 166 may include calculating a score for each of a number of permutation related mappings based on a number of CPRS determined locations of the group of suspect defects.

[0062] The score may reflect the distribution of multiple CPRS decision positions in the group, with a more compact distribution receiving a higher score.

[0063] FIG. 4 shows (a) a distribution 271 of estimated multitude of CPRS determined locations for a group of suspected defects, (b) a histogram 272 of the distances of the multitude of CPRS determined locations from the center of the distribution, and (c) an example of a matched filter function 273 applied to the distances from the center to provide a score that is a weighted sum of the distances from the center.

[0064] Referring back to FIG. 1, step 168 may include selecting the permutation with the highest score, for example the highest weighted sum.

[0065] Step 160 may be followed by step 170 of determining whether the selected substitution related mapping should be used to convert OWIS determined locations of suspected defects in the substrate to CPRS determined locations of suspected defects in the substrate.

[0066] The determination can be made in various ways, for example, by determining whether the selected substitution association mapping exhibits a sufficiently high certainty level (CL).

[0067] Step 170 may include step 172 of calculating the chance of a uniformly distributed random sample occurring after applying the selected permutation related mapping within a predefined field of view (FOV) of the CPRS having a predefined width d, the predefined width (d) being smaller than the initial FOV of the CPRS, i.e. the predefined width (L) of the FOV of the CPRS used before applying method 100.

[0068] The value of likelihood (n) is provided as an input to the method 100. The value of the probability (P) that the suspected defect is within the predefined FOV is also provided as an input to the method 100, (d / L) 2 is equal to.

[0069] Step 172 may include determining CL by calculating the following equation:

number

[0070] If a decision is made to use the selected substitution association mapping (in step 170), step 170 may be followed by step 180 of converting OWIS determined locations of suspected defects on the substrate to CPRS determined locations of suspected defects on the substrate by using the selected substitution association mapping.

[0071] Step 180 may be followed by step 190 of reviewing the suspected defects based on the CPRS determined locations of the suspected defects on the substrate.

[0072] This may include defining a review search window that includes CPRS determined locations of suspected defects on the substrate, and reviewing the suspected defects that are in the review search window.

[0073] If it is decided (in step 170) not to use the selected replacement related mapping, step 170 may be followed by step 174 of increasing the number of suspected defects in the group, i.e., increasing the number of suspected defects to be included in the multiplicity of suspected defects.

[0074] An increase in the number of suspected defects may result in a longer execution period for method 100, however, by evaluating more suspected defects, the level of confidence associated with execution of method 100 may be increased.

[0075] Step 174 may be followed by step 130 .

[0076] Multiple iterations of steps 130, 140, 150, 160, 170, and 174 may be performed. The iterations may be stopped when a certain level of confidence is obtained, additionally or alternatively after a predefined number of iterations has been reached.

[0077] Method 100 (specifically, step 150) depicts computing a single permutation association mapping for each permutation.

[0078] Note that step 150 may involve computing a different permutation association mapping for each permutation.

[0079] The different permutation association mappings may include the permutation association mappings described above and one or more additional permutation association mappings.

[0080] Different permutation-related mappings for each permutation may differ from each other by their computational complexity. For example, there may be one or more sources of position error, such as XY offset, scaling, and rotation. Different permutations may take into account different numbers of sources of position error. A simple permutation-related mapping may take into account only one source of position error, for example, XY offset. A more complex permutation-related mapping may take into account two or more sources of position error, for example, XY offset, scaling, and rotation.

[0081] The selection of which type (or types) of replacement association mapping to use may be preset, may change over time, may change from one iteration (of steps 130, 140, 150, 160, 170, and 174) to another, may be based on a comparison between scores associated with different types of replacement association mapping, etc.

[0082] For example, a simple permutation association mapping may be used during one or more initial iterations of steps 130, 140, 150, 160, 170, and 174. If one or more additional iterations need to be performed, the confidence level obtained during one of the initial iterations may indicate that a more complex permutation association mapping should be evaluated. If the confidence level is not high enough, it may indicate that the simple permutation association mapping is not accurate enough, and a more complex permutation association mapping may be used.

[0083] Even if it is decided to use a more complex permutation association mapping, the method may still apply a simple permutation association mapping and then compare the scores of the simple and more complex permutation association mappings to determine which permutation association mapping to use for the current or next iteration.

[0084] The selection of the type of replacement relation mapping may also be based on the resources available to perform the method 100 and / or based on the time allotted to complete the method 100. More resources and / or more available time may merit using a more complex replacement relation mapping.

[0085] If more than one type of permutation association mapping is selected, the method 100 may include at least one of the following: o Calculating an additional permutation association mapping for each permutation of the suspected defect among the multiple permutations of the suspected defect to provide a multiple additional permutation association mapping. For at least one permutation of the multiple permutations, the additional permutation association mapping of the permutation differs in complexity from the permutation association mapping of the permutation. For at least one permutation of the multiple permutations, the additional permutation association mapping of the permutation differs in a number of sources of position error from the permutation association mapping of the permutation. For example, the permutation association mapping may take into account only an XY offset, but the additional permutation association mapping may take into account an XY offset and at least one of a scaling and a rotation. o Calculate a score for each of an additional number of permutation related mappings to provide an additional number of scores. o Selecting the selected permutation based on the majority score (of the multiple permutation related mappings) and an additional majority score.

[0086] FIG. 5 illustrates the method 102.

[0087] The method 102 may begin by receiving OWIS determined locations of suspected defects on a wafer, step 110. The OWIS determined locations of suspected defects on a wafer may be received by a CPRS.

[0088] Step 110 may be followed by step 120 of reviewing a number of suspected defects.

[0089] Step 120 may be followed by a step 130 of filtering the number of suspected defects to select, based on one or more selection criteria, suspected defects that form a group of suspected defects.

[0090] Step 130 may be followed by step 140 of defining multiple permutations of the suspected defects, each permutation of the suspected defects being formed by a subgroup of the group of suspected defects.

[0091] Step 140 may be followed by step 152 of computing a different permutation association mapping for each permutation of the suspected defect (among multiple permutations of the suspected defect).

[0092] The permutation related mappings with different permutations can be considered as a set of permutation related mappings.

[0093] The result of step 152 is a set of multiple permutation relational mappings.

[0094] Step 152 may be followed by step 160 of selecting the selected permutation related mapping.

[0095] The selection should be made from among a set of multiple permutation related mappings, and therefore steps 162, 164, 166, and 168 may be applied to all permutation related mappings in the set of multiple permutation related mappings.

[0096] Step 160 may further include a step 169 of determining what type of substitution to use during the next iteration of steps 130 , 140 , 152 , 160 , 170 , and 174 .

[0097] One type of permutation association mapping can be created that provides a better tradeoff between CL and resource consumption. In yet another example, a simpler permutation association mapping may be selected as long as it provides at least the predefined CL.

[0098] Step 160 may be followed by step 170 of determining whether the selected substitution related mapping should be used to convert OWIS determined locations of suspected defects in the substrate to CPRS determined locations of suspected defects in the substrate.

[0099] The determination can be made in various ways, for example, by determining whether the selected substitution association mapping exhibits a sufficiently high certainty level (CL).

[0100] If a decision is made to use the selected substitution association mapping (in step 170), step 170 may be followed by step 180 of converting OWIS determined locations of suspected defects on the substrate to CPRS determined locations of suspected defects on the substrate by using the selected substitution association mapping.

[0101] Step 180 may be followed by step 190 of reviewing the suspected defects based on the CPRS determined locations of the suspected defects on the substrate.

[0102] If it is decided (in step 170) not to use the selected replacement related mapping, step 170 may be followed by step 174 of increasing the number of suspected defects in the group, i.e., increasing the number of suspected defects to be included in the multiplicity of suspected defects.

[0103] An increase in the number of suspected defects may result in a longer execution period for method 100, however, by evaluating more suspected defects, the level of confidence associated with execution of method 100 may be increased.

[0104] Step 174 may be followed by step 130 .

[0105] FIG. 6 is an example of a charged particle review system (CPRS) 200 and a wafer 10 .

[0106] The CPRS 200 includes an imager 210 , a processor 220 , and a memory unit 230 .

[0107] The processor 220 may include one or more processing circuits, such as a microprocessor, a preprocessor (such as an image preprocessor), a graphics processor, a central processing unit (CPU), support circuits, a digital signal processor, an integrated circuit, memory, or other types of devices suitable for executing applications and for performing any of the methods described above.

[0108] The imager 210 may be an electron beam imager, an electron beam microscope, an ion microscope, an ion imager, etc. The electron beam microscope may be a scanning electron microscope, a transmission electron microscope, etc.

[0109] The system 200 may be configured to perform the method 102 and may additionally or alternatively be configured to perform the method 100.

[0110] For example, the imager 210 may be configured to illuminate the suspected defects with a charged particle beam.

[0111] The processor 220 and / or the memory unit 230 may be configured to perform other steps of the method 100 and / or the method 102.

[0112] For example, the memory unit 230 may be configured to store Optical Wafer Inspection System (OWIS) determined locations of groups of suspect defects.

[0113] For example, the processor 220 may be configured to: o determining a CPRS determined location of a group of suspected defects, determining based at least in part on an OWIS determined location of the group of suspected defects, and determining that the suspected defects of the group are only a portion of the suspected defects of the substrate. o computing a permutation association mapping for each permutation of the suspected defect among the multiple permutations of the suspected defects to provide a multiple permutation association mapping, where each permutation of the suspected defect maps a CPRS decision position of the permutation of the suspected defect to an OWIS decision position of the permutation of the suspected defect, where each permutation of the suspected defect is formed by a subgroup of the group of the suspected defects. o Selecting the selected substitution association mapping. o Determining whether a selected substitution association mapping should be used to convert OWIS determined locations of suspected defects on the substrate to CPRS determined locations of suspected defects on the substrate. o upon determining to use the selected substitution association mapping, converting the OWIS determined locations of the suspected defects on the substrate to CPRS determined locations of the suspected defects on the substrate by using the selected substitution association mapping.

[0114] In the foregoing specification, embodiments of the present disclosure have been described with reference to specific examples of embodiments of the present disclosure. It will, however, be apparent that various changes and modifications can be made therein without departing from the broader spirit and scope of the embodiments of the present disclosure as set forth in the appended claims.

[0115] Terms such as "front," "rear," "top," "bottom," "upper," "lower," and the like in this specification and claims, if any, are used for descriptive purposes and not necessarily to describe permanent relative positions. It will be understood that terms so used are interchangeable under appropriate circumstances such that the embodiments of the disclosure described herein can, for example, operate in orientations other than those illustrated or otherwise described herein.

[0116] The connections discussed herein may be any type of connection suitable for transferring signals from or to the respective nodes, units, or devices, for example, via intermediate devices. Thus, unless otherwise indicated or stated, a connection may be, for example, a direct connection or an indirect connection. A connection may be illustrated or described with reference to being a single connection, multiple connections, unidirectional connections, or bidirectional connections. However, different embodiments may vary the implementation of the connections. For example, separate unidirectional connections may be used rather than bidirectional connections, and vice versa. Furthermore, multiple connections may be replaced with a single connection that transfers multiple signals serially or in a time division multiplexed manner. Similarly, a single connection carrying multiple signals may be separated into various different connections carrying subsets of these signals. Hence, many options exist for transferring signals.

[0117] An arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Thus, any two components herein that are combined to achieve a particular functionality can be considered to be "associated" with one another such that the desired functionality is achieved, regardless of architecture or intermediate components. Similarly, any two components so associated can also be considered to be "operably connected" or "operably coupled" with one another to achieve the desired functionality.

[0118] Moreover, those skilled in the art will recognize that the boundaries between the operations described above are merely exemplary. Multiple operations may be combined into a single operation, a single operation may be distributed into additional operations, and operations may be performed with at least partial overlap in time. Moreover, alternative embodiments may include multiple instances of a particular operation, and the order of operations may be changed in various other embodiments.

[0119] Further, for example, in one embodiment, the illustrated examples may be implemented as circuits located on a single integrated circuit or within the same device. Alternatively, the examples may be implemented as any number of separate integrated circuits or separate devices interconnected with each other in any suitable manner.

[0120] However, other variations, modifications, and alternatives are also possible, and the specification and drawings are accordingly to be regarded in an illustrative rather than a restrictive sense.

[0121] In the claims, reference signs placed between parentheses shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of other elements or steps than those recited in the claim. Furthermore, the terms "a" or "an" as used herein are defined as one or more than one. Furthermore, the use of introductory phrases such as "at least one" and "one or more" in the claims shall not be construed as implying that the introduction of another claim element with the indefinite article "a" or "an" limits any particular claim containing such introduced claim element to an embodiment of the present disclosure containing only one such element, even if the same claim contains the introductory phrase "one or more" or "at least one" and the indefinite article "a" or "an". The same applies to the use of definite articles. Unless otherwise stated, terms such as "first" and "second" are used to distinguish between the elements that such terms describe as appropriate. Thus, these terms are not intended to necessarily indicate a temporal or other priority of such elements. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage.

[0122] While certain features of the embodiments of the present disclosure have been illustrated and described herein, many variations, substitutions, modifications, and equivalents will now occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all such variations and modifications as fall within the true spirit of the embodiments of the present disclosure. [Explanation of symbols]

[0123] 10 Wafers 200 Charged Particle Review System (CPRS) 201 First Area 202 Second Area 203 The Third Region 204 The Fourth Region 205 The Fifth Region 210 Imager 220 Processor 230 Memory Unit 281 CPRS Coordinate Matrix 282 OWIS Coordinate Matrix 283 Permutation related mapping matrix

Claims

1. 1. A method for determining a location of a suspected defect in a substrate, comprising: determining, with a charged particle review system (CPRS), CPRS determined locations of a group of suspected defects, wherein determining the CPRS determined locations of the group of suspected defects is based at least in part on optical wafer inspection system (OWIS) determined locations of the group of suspected defects, and wherein the suspected defects of the group are only a portion of the suspected defects of the substrate; calculating, for each permutation of the suspected defects among the multiple permutations of the suspected defects to provide a multiple permutation association mapping, each permutation association mapping mapping a CPRS determined location of the suspected defect of the permutation to an OWIS determined location of the suspected defect of the permutation, each permutation of the suspected defects being formed by a subgroup of the group of the suspected defects; Selecting a selected substitution association mapping; determining whether to use the selected substitution relational mapping to convert the OWIS determined locations of the suspected defects on the substrate to CPRS determined locations of the suspected defects on the substrate; upon determining to use the selected substitution relation mapping, converting the OWIS determined locations of the suspected defects on the substrate to CPRS determined locations of the suspected defects on the substrate by using the selected substitution relation mapping; determining a level of certainty of the selected permutation association mapping; Including, A method, wherein the determining whether to use the selected permutation association mapping is based on the certainty level of the selected permutation association mapping.

2. 2. The method of claim 1, further comprising: upon determining not to use the selected replacement related mapping, increasing a number of suspect defects in the group; and jumping to determining the CPRS determined locations for the group.

3. 2. The method of claim 1, comprising: calculating a score for each of the multiple permutation association mappings to provide a multiple score; and selecting the selected permutation based on the multiple scores.

4. 4. The method of claim 3, comprising applying each of the multiple permutation association mappings to OWIS determined positions of the group of suspect defects to provide estimated multiple CPRS determined positions of the group of suspect defects, wherein the calculating of the score for each of the multiple permutation association mappings is based on the multiple CPRS determined positions of the group of suspect defects.

5. 2. The method of claim 1, comprising: computing an additional permutation association mapping for each permutation of a suspected defect among the multiple permutations of the suspected defect to provide multiple additional permutation association mappings.

6. The method of claim 5 , wherein for at least one permutation of the multiple permutations, an additional permutation related mapping of the permutation differs in complexity from the permutation related mapping of the permutation.

7. The method of claim 5 , wherein for at least one permutation of the multiple permutations, an additional permutation-related mapping of the permutation has a different number of sources of position error than the permutation-related mapping of the permutation.

8. 6. The method of claim 5, comprising: calculating a score for each of the multiple permutation associated mappings to provide a multiple score; calculating a score for each of the additional multiple permutation associated mappings to provide an additional multiple score; and selecting the selected permutation based on the multiple scores and the additional multiple scores.

9. 2. The method of claim 1, comprising: reviewing a number of suspected defects; and selecting suspected defects from the number based on one or more selection criteria to provide a group of the suspected defects.

10. The method of claim 9 , comprising searching for the multiple suspected defects in different areas of the substrate.

11. 1. A charged particle review system (CPRS), comprising: a memory unit configured to store optical wafer inspection system (OWIS) determined locations of a group of suspect defects; determining CPRS determined locations of a group of suspected defects on a substrate, wherein determining the CPRS determined locations of the group of suspected defects is based at least in part on the OWIS determined locations of the group of suspected defects, and wherein the suspected defects of the group are only a portion of the suspected defects on the substrate; calculating, for each permutation of the suspected defects among the multiple permutations of the suspected defects to provide a multiple permutation association mapping, each permutation association mapping mapping a CPRS determined location of the suspected defect of the permutation to an OWIS determined location of the suspected defect of the permutation, each permutation of the suspected defects being formed by a subgroup of the group of the suspected defects; Selecting a selected substitution association mapping; determining whether to use the selected substitution relational mapping to convert the OWIS determined locations of the suspected defects on the substrate to CPRS determined locations of the suspected defects on the substrate; upon determining to use the selected substitution relation mapping, converting the OWIS determined locations of the suspected defects on the substrate to CPRS determined locations of the suspected defects on the substrate by using the selected substitution relation mapping; determining a level of certainty of the selected permutation association mapping; a processor configured to: Equipped with A charged particle review system (CPRS), wherein the determining whether to use the selected permutation related mapping is based on the confidence level of the selected permutation related mapping.

12. determining, with a charged particle review system (CPRS), CPRS determined locations of a group of suspected defects on a substrate, wherein determining the CPRS determined locations of the group of suspected defects is based at least in part on optical wafer inspection system (OWIS) determined locations of the group of suspected defects, and wherein the suspected defects of the group are only a portion of the suspected defects on the substrate; calculating, for each permutation of the suspected defects among the multiple permutations of the suspected defects to provide a multiple permutation association mapping, each permutation association mapping mapping a CPRS determined location of the suspected defect of the permutation to an OWIS determined location of the suspected defect of the permutation, each permutation of the suspected defects being formed by a subgroup of the group of the suspected defects; Selecting a selected substitution association mapping; determining whether to use the selected substitution relational mapping to convert the OWIS determined locations of the suspected defects on the substrate to CPRS determined locations of the suspected defects on the substrate; upon determining to use the selected substitution relation mapping, converting the OWIS determined locations of the suspected defects on the substrate to CPRS determined locations of the suspected defects on the substrate by using the selected substitution relation mapping; determining a level of certainty of the selected permutation association mapping; storing instructions for performing The non-transitory computer readable medium, wherein the determining whether to use the selected permutation association mapping is based on the certainty level of the selected permutation association mapping.

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