Method and device for measuring property parameters of material to be measured

Abstract

The invention discloses a method and a device for measuring property parameters of a to-be-measured material, and relates to the technical field of semiconductors. The measurement method comprises the following steps: establishing a preset model according to preset parameter information of a preset alignment mark, the preset model representing a corresponding relationship between a to-be-measured property parameter of a to-be-measured material in the preset alignment mark and a preset alignment signal of the preset alignment mark, the preset parameter information comprises geometric information of a preset alignment mark, and refractive index information and extinction coefficient information of a known material in the preset alignment mark; according to the target property parameter of the to-be-tested material in the preset alignment mark and a preset model, determining a simulation alignment signal of the preset alignment mark; according to the actual alignment signal and the simulation alignment signal of the preset alignment mark, an evaluation function is established, and the evaluation function is used for representing the deviation between the actual alignment signal and the simulation alignment signal; and obtaining a target property parameter enabling the evaluation function to meet a preset condition as a to-be-tested property parameter. Measurement efficiency is high and cost is low.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor technology, and in particular to a method for measuring a property parameter of a material to be measured and a measuring device thereof. BACKGROUND

[0002] With the continuous development of the semiconductor industry, new materials are gradually introduced. The refractive index and extinction coefficient of the new material are unknown because it is impossible to judge the influence of the introduced new material on the alignment performance of the lithography machine through simulation. When the thickness of the new material is set unreasonably, a large overlay error will be caused, which will affect the yield of the product. Therefore, the measurement of the refractive index and extinction coefficient of the new material is an important work. SUMMARY

[0003] The present disclosure provides a method for measuring a property parameter of a material to be measured and a measuring device thereof, which can realize the measurement of the property parameter of the material to be measured, and has high measurement efficiency and low measurement cost.

[0004] A method for measuring a property parameter of a material to be measured, comprising:

[0005] establishing a preset model according to preset parameter information of a preset alignment mark, the preset model representing a corresponding relationship between a to-be-measured property parameter of a material to be measured in the preset alignment mark and a preset alignment signal of the preset alignment mark, the preset parameter information including geometric information of the preset alignment mark, refractive index information and extinction coefficient information of a known material in the preset alignment mark;

[0006] confirming a simulation alignment signal of the preset alignment mark according to a target property parameter of the material to be measured in the preset alignment mark and the preset model;

[0007] establishing an evaluation function according to an actual alignment signal of the preset alignment mark and the simulation alignment signal of the preset alignment mark, the evaluation function being used to represent a deviation between the actual alignment signal and the simulation alignment signal;

[0008] obtaining a target property parameter that makes the evaluation function satisfy a preset condition as the to-be-measured property parameter.

[0009] In one of the embodiments, before the step of establishing the preset model according to the preset parameter information of the preset alignment mark, the method further comprises:

[0010] forming the preset alignment mark;

[0011] measuring actual geometric information and an actual alignment signal of the preset alignment mark;

[0012] The step of establishing the preset model according to the preset parameter information of the preset alignment mark comprises:

[0013] Establish a preset model based on the actual parameter information of the preset alignment mark;

[0014] The actual parameter information includes the actual geometric information, the refractive index information and extinction coefficient information of the known material in the preset alignment mark.

[0015] In one embodiment, before establishing the preset model based on the preset parameter information of the preset alignment mark, the method further includes:

[0016] Create a preset alignment mark;

[0017] The actual alignment signal of the preset alignment mark is obtained by measurement;

[0018] The step of establishing a preset model based on preset parameter information of preset alignment marks includes:

[0019] A preset model is established based on the theoretical parameter information of the preset alignment mark. The theoretical parameter information includes the theoretical geometric information of the preset alignment mark, the refractive index information and extinction coefficient information of the known materials in the preset alignment mark.

[0020] In one embodiment, before confirming the simulated alignment signal of the preset alignment mark based on the target property parameters of the material to be tested in the preset alignment mark and the preset model, the process includes:

[0021] Determine the permissible range of the property parameter to be measured;

[0022] Select the target property parameters within the permitted range.

[0023] In one embodiment, when the absolute value of the evaluation function is less than or equal to a first preset value, the evaluation function is determined to satisfy a preset condition.

[0024] In one embodiment, the preset alignment mark includes a plurality of alignment marks comprising the material under test, each alignment mark having a different structure and / or position on the wafer. The step of confirming the simulated alignment signal of the preset alignment mark based on the target property parameters and the preset model includes:

[0025] Based on the target property parameters and the preset model corresponding to the alignment mark, the simulated alignment signal corresponding to the alignment mark is obtained;

[0026] The evaluation function is used to characterize the overall deviation between the actual alignment signal and the simulated alignment signal corresponding to each of the preset alignment marks.

[0027] In one embodiment, the evaluation function includes a plurality of intermediate evaluation functions corresponding to the alignment mark, wherein the intermediate evaluation functions characterize the deviation between the actual alignment signal and the simulated alignment signal of the alignment mark; when the deviation corresponding to each of the intermediate evaluation functions is less than or equal to a second preset value, the evaluation function is determined to meet the preset condition.

[0028] In one embodiment, the preset alignment mark includes a substrate layer, a pattern layer located on the surface of the substrate layer, and a cover layer located on the surface of the pattern layer. The pattern layer includes a first pattern structure and a second pattern structure disposed adjacent to each other in a direction parallel to the substrate layer.

[0029] The material of the substrate layer, the first patterned structure, the second patterned structure, or the cover layer includes the material to be tested.

[0030] This disclosure also provides a measuring device for the property parameters of the material to be tested, including:

[0031] A modeling module is used to establish a preset model based on preset parameter information of a preset alignment mark. The preset model characterizes the correspondence between the test property parameters of the material under test in the preset alignment mark and the preset alignment signal. The preset parameter information includes the geometric information of the preset alignment mark, the refractive index information and extinction coefficient information of the known material in the preset alignment mark.

[0032] The computation module is used to confirm the simulated alignment signal of the preset alignment mark based on the target property parameters of the material to be tested in the preset alignment mark and the preset model, and to establish an evaluation function based on the actual alignment signal and the simulated alignment signal of the preset alignment mark, and to obtain the target property parameters that make the evaluation function meet the preset conditions as the property parameters to be tested. The evaluation function is used to characterize the deviation between the actual alignment signal and the simulated alignment signal of the preset alignment mark.

[0033] In one embodiment, the measuring device for the property parameters of the material under test further includes:

[0034] A measurement module is used to measure the actual alignment signal of the preset alignment mark.

[0035] In one embodiment, the measurement module is further used to measure the actual geometric information of the preset alignment mark; the modeling module establishes the preset model based on the actual parameter information of the preset alignment mark, wherein the actual parameter information includes the actual geometric information of the preset alignment mark, the refractive index information and extinction coefficient information of the known material in the preset alignment mark.

[0036] In one embodiment, the measuring device for the property parameters of the material under test further includes:

[0037] The input module is used to input the theoretical geometric information of the preset alignment mark, the refractive index information and extinction coefficient information of the known material in the preset alignment mark; the modeling module establishes the preset model based on the theoretical parameter information of the preset alignment mark, the theoretical parameter information including the theoretical geometric information of the preset alignment mark, the refractive index information and extinction coefficient information of the known material in the preset alignment mark.

[0038] In one embodiment, the computation module is used to determine that the evaluation function meets a preset condition when the absolute value of the evaluation function is less than or equal to a first preset value.

[0039] In one embodiment, the computing module is further configured to determine the permissible range of the property parameter to be tested, and based on an intelligent algorithm, determine the property parameter to be tested within the permissible range of the property parameter to be tested according to the evaluation function.

[0040] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the method for measuring the property parameters of the material to be tested as described in any of the preceding claims.

[0041] A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method for measuring the property parameters of the material to be tested as described in any of the preceding claims.

[0042] The aforementioned method for measuring the property parameters of the material under test involves establishing a preset model based on preset parameter information of preset alignment marks. Based on the target property parameters of the material under test within the preset alignment marks and the preset model, the simulated alignment signal of the preset alignment marks is confirmed. An evaluation function is established based on the actual alignment signal and the simulated alignment signal of the preset alignment marks. The target property parameters that satisfy preset conditions are then obtained and used as the property parameters to be measured. This measurement method, by including the actual alignment signal and the preset model of the preset alignment marks, confirms the property parameters to be measured, achieving high measurement efficiency and low cost.

[0043] In the aforementioned measurement device for the property parameters of the material under test, the modeling module establishes a preset model based on the preset parameter information of the preset alignment mark. The calculation module confirms the simulated alignment signal of the preset alignment mark based on the target property parameters of the material under test in the preset alignment mark and the preset model. Based on the actual alignment signal and the simulated alignment signal of the preset alignment mark, an evaluation function is established, and the target property parameters that make the evaluation function satisfy preset conditions are obtained as the property parameters to be measured. This measurement device confirms the property parameters to be measured of the material under test by including the actual alignment signal and the preset model of the preset alignment mark, thus realizing the measurement of the property parameters to be measured of the material under test. Furthermore, it boasts high measurement efficiency and low measurement cost. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a flowchart illustrating the measurement method of the property parameters of the material under test in some embodiments;

[0046] Figure 2 This is a cross-sectional schematic diagram of the pre-set alignment marks in some embodiments;

[0047] Figure 3 This is a schematic diagram of the structure of the measuring device for the property parameters of the material under test in some embodiments;

[0048] Figure 4 This is a schematic diagram of the structure of the measuring device for the property parameters of the material under test in some other embodiments;

[0049] Figure 5 This is a schematic diagram of the structure of the measuring device for the property parameters of the material to be tested in some other embodiments.

[0050] Explanation of reference numerals in the attached figures:

[0051] Substrate layer 102, pattern layer 104, cover layer 106, first pattern structure 202, second pattern structure 204, modeling module 302, calculation module 304, measurement module 306, input module 308. Detailed Implementation

[0052] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate preferred embodiments of the application. However, this application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0054] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, parts, regions, layers, doping types, and / or portions, these elements, parts, regions, layers, doping types, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, part, region, layer, doping type, or portion from another element, part, region, layer, doping type, or portion. Therefore, without departing from the teachings of this invention, the first element, component, region, layer, doping type, or portion discussed below may be represented as a second element, component, region, layer, or portion; for example, the first doping type may be referred to as the second doping type, and similarly, the second doping type may be referred to as the first doping type; the first doping type and the second doping type are different doping types, for example, the first doping type may be P-type and the second doping type may be N-type, or the first doping type may be N-type and the second doping type may be P-type.

[0055] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “under,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0056] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that when the terms “comprise” and / or “comprising” are used in this specification, the presence of the stated feature, integer, step, operation, element, and / or part is established, but the presence or addition of one or more other features, integers, steps, operations, elements, parts, and / or groups is not excluded. Meanwhile, when used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0057] Figure 1 This is a flowchart illustrating the measurement methods for the property parameters of the material under test in some embodiments, such as... Figure 1 As shown, in this embodiment, a method for measuring the property parameters of a material to be tested is provided, including:

[0058] S102, Establish a preset model based on the preset parameter information of the preset alignment mark.

[0059] A preset model of the preset alignment mark is established based on the preset parameter information of the preset alignment mark. The preset model represents the correspondence between the test property parameters of the material under test in the preset alignment mark and the preset alignment signal of the preset alignment mark. In the preset model, the test property parameters of the material under test and the preset alignment signal are unknowns. When the test property parameters are determined, a definite preset alignment signal can be obtained. The test property parameters include the test refractive index information and the test extinction coefficient information of the material under test.

[0060] The preset parameter information includes the geometric information of the preset alignment mark, the refractive index information and extinction coefficient information of the known material in the preset alignment mark, wherein the geometric information of the preset alignment mark refers to information related to the geometry of the preset alignment mark, including the arrangement information of the film structure composed of the known material and the film structure composed of the material to be tested in the preset alignment mark, the thickness information of each film structure, and the size information of each film structure; the refractive index information of the known material is the refractive index of the known material at the preset wavelength corresponding to the property parameter to be tested, and the extinction coefficient information of the known material is the extinction coefficient of the known material at the preset wavelength corresponding to the property parameter to be tested. For example, the preset wavelength includes at least one of 532nm, 633nm, 780nm, or 852nm.

[0061] S104. Based on the target property parameters of the material to be tested in the preset alignment mark and the preset model, confirm the simulation alignment signal of the preset alignment mark.

[0062] The target property parameters of the material to be tested are set in the preset alignment mark. Based on the vector diffraction theory, and according to the target property parameters and the preset model, the simulated alignment signal of the preset alignment mark is obtained when the test property parameters of the material to be tested in the preset alignment mark are the target property parameters.

[0063] S106, Establish an evaluation function based on the actual alignment signal of the preset alignment mark and the simulated alignment signal of the preset alignment mark.

[0064] Based on the actual alignment signal and the simulated alignment signal of the preset alignment mark, an evaluation function F is established. The evaluation function F is used to characterize the deviation between the actual alignment signal WQ0 and the simulated alignment signal WQn. For example, the evaluation function F = WQ0 - WQn.

[0065] S108, obtain the target property parameters that make the evaluation function meet the preset conditions, and use them as the property parameters to be tested.

[0066] The target property parameters that make the evaluation function F satisfy the preset conditions are obtained and used as the test property parameters of the material under test, thus realizing the measurement of the test property parameters of the material under test. The preset condition is that the deviation between the actual alignment signal WQ0 and the simulated alignment signal WQn can be ignored. At this time, the target property parameters of the material under test in the preset alignment mark are equal to the test property parameters of the material under test in the preset alignment mark. The target property parameters of the material under test at this time can be used as the test property parameters of the material under test.

[0067] The aforementioned method for measuring the property parameters of the material under test involves establishing a preset model based on preset parameter information of preset alignment marks. Based on the target property parameters of the material under test within the preset alignment marks and the preset model, the simulated alignment signal of the preset alignment marks is confirmed. An evaluation function is established based on the actual alignment signal and the simulated alignment signal of the preset alignment marks. The target property parameters that satisfy preset conditions are then obtained and used as the property parameters to be measured. This measurement method, by including the actual alignment signal and the preset model of the preset alignment marks, confirms the property parameters to be measured, achieving high measurement efficiency and low cost.

[0068] Figure 2 This is a cross-sectional schematic diagram of a preset alignment mark in some embodiments. In one embodiment, the preset alignment mark includes a substrate layer 102, a pattern layer 104, and a cover layer 106. The pattern layer 104 is located on the surface of the substrate layer 102 and includes a first pattern structure 202 and a second pattern structure 204 disposed adjacent to each other in a direction parallel to the substrate layer 102. The cover layer 106 is located on the surface of the pattern layer 104 away from the substrate layer 102. The material of the substrate layer 102, the first pattern structure 202, the second pattern structure 204, or the cover layer 206 includes the material to be tested, and the materials of the first pattern structure 202 and the second pattern structure 204 are different.

[0069] Understandably, in some embodiments, the material of the substrate 102 is the material to be measured, and the materials of the first patterned structure 202, the second patterned structure 204, and the capping layer 106 are known materials. Specifically, the material of the capping layer 106 is the same as the material of the first patterned structure 202, or the material of the capping layer 106 is the same as the material of the second patterned structure 204, or the materials of the capping layer 106, the first patterned structure 202, and the second patterned structure 204 are three different materials. When the material of the capping layer 106 is the same as the material of the first patterned structure 202, or the material of the capping layer 106 is the same as the material of the second patterned structure 204, the number of data types involved in the measurement process is small, and the measurement rate is fast.

[0070] In other embodiments, the material of the first patterned structure 202 is the material to be measured, while the materials of the substrate layer 102, the second patterned structure 204, and the capping layer 106 are known materials. Specifically, the material of the capping layer 106 is the same as the material of the second patterned structure 204, or the material of the capping layer 106 is the same as the material of the substrate layer 102, or the materials of the capping layer 106, the substrate layer 102, and the second patterned structure 204 are three different materials, or the materials of the capping layer 106, the substrate 102, and the second patterned structure 204 are the same. When the materials of the capping layer 106, the substrate 102, and the second patterned structure 204 are the same, the measurement process involves fewer types of data and has a faster measurement rate.

[0071] In some other embodiments, the material of the capping layer 106 is the material to be measured, while the materials of the substrate layer 102, the first patterned structure 202, and the second patterned structure 204 are known materials. Specifically, the materials of the substrate layer 102 and the second patterned structure 204 are the same, or the materials of the substrate layer 102 and the second patterned structure 204 are the same, or the materials of the capping layer 106, the substrate layer 102, and the second patterned structure 204 are three different materials. When the materials of the substrate layer 102 and the second patterned structure 204 are the same, or when the materials of the substrate layer 102 and the second patterned structure 204 are the same, the measurement process involves fewer types of data and has a faster measurement rate.

[0072] In one embodiment, before establishing the preset model based on the preset parameter information of the preset alignment mark, steps S202-S204 are further included.

[0073] S202, forming a preset alignment mark.

[0074] S204, the actual geometric information and actual alignment signal of the preset alignment mark are measured.

[0075] The step of establishing a preset model based on the preset parameter information of the preset alignment mark includes: establishing a preset model based on the actual parameter information of the preset alignment mark; wherein, the actual parameter information includes the actual geometric information, the refractive index information and extinction coefficient information of the known material in the preset alignment mark.

[0076] Specifically, a preset alignment mark is formed on the carrier wafer. Next, the preset alignment mark on the carrier wafer is measured to obtain its actual geometric information and actual alignment signal at a preset wavelength. The actual geometric information includes the thickness and size information of each film layer in the preset alignment mark. Then, a preset model of the preset alignment mark is established based on its actual parameter information. This actual parameter information includes the actual geometric information, the refractive index information of the known material in the preset alignment mark, and the extinction coefficient information. This eliminates the influence of process deviations on the preset model and improves the accuracy of measuring the measured property parameters of the material under test, including the measured refractive index and the measured extinction coefficient.

[0077] In one embodiment, before establishing the preset model based on the preset parameter information of the preset alignment mark, steps S302-S304 are further included.

[0078] S302, forming a preset alignment mark.

[0079] S304, the actual alignment signal of the preset alignment mark is measured.

[0080] The step of establishing a preset model based on the preset parameter information of the preset alignment mark includes: establishing a preset model based on the theoretical parameter information of the preset alignment mark, wherein the theoretical parameter information includes the theoretical geometric information of the preset alignment mark, the refractive index information of the known material in the preset alignment mark, and the extinction coefficient information of the known material.

[0081] Specifically, a preset alignment mark is formed on the carrier wafer. Next, the preset alignment mark on the carrier wafer is measured to obtain the actual alignment signal of the preset alignment mark at a preset wavelength. Then, a preset model of the preset alignment mark is established based on its theoretical parameter information. This theoretical parameter information includes the theoretical geometric information of the preset alignment mark, the theoretical refractive index information and the theoretical extinction coefficient information of the known materials in the preset alignment mark. The theoretical geometric information is the design information of the preset alignment mark, including the theoretical thickness information and the theoretical size information of each film layer structure in the preset alignment mark. This eliminates the step of measuring the actual parameter information of the preset alignment mark, improving the rate of measuring the measured property parameters of the material under test, including the measured refractive index and the measured extinction coefficient.

[0082] In one embodiment, before confirming the simulated alignment signal of the preset alignment mark based on the target property parameters of the material under test in the preset alignment mark and the preset model, the method includes: determining the permissible range of the property parameters to be measured; and selecting the target property parameters within the permissible range. This step narrows the selection range of the target property parameters and improves the efficiency of measuring the property parameters of the material under test.

[0083] Specifically, based on process experience, the permissible range of the test property parameters of the material under test in the preset alignment marks is determined. The permissible range represents the approximate range of the test property parameters of the material under test. Next, the target property parameter is selected within the permissible range, and based on vector diffraction theory and the preset model of the preset alignment marks, the simulated alignment signal when the test property parameters of the material under test in the preset alignment marks are the target property parameters is confirmed. Based on an intelligent algorithm and according to an evaluation function, the test property parameters of the material under test are determined.

[0084] In one embodiment, when the absolute value of the evaluation function is less than or equal to a first preset value, the evaluation function is determined to meet a preset condition, such as the first preset value being 0. In the process of confirming the test property parameters of the test material, no prior data collection is required, which improves the speed of measuring the test property parameters of the test material and saves costs.

[0085] In one embodiment, the preset alignment marks include multiple alignment marks including the material under test (TUT), each alignment mark having a different structure and / or position on the wafer. The step of confirming the simulated alignment signal of the preset alignment marks based on target property parameters and the preset model includes: obtaining the simulated alignment signal corresponding to each alignment mark based on the target property parameters and the preset model corresponding to each alignment mark; wherein the evaluation function is used to characterize the overall deviation between the actual alignment signal and the simulated alignment signal corresponding to each alignment mark in the preset alignment marks. This setting avoids the problem of being unable to accurately determine the TUT property parameters when multiple target property parameters cause the evaluation function to meet preset conditions.

[0086] Specifically, the preset alignment marks include multiple alignment marks with different structures or positions, and the preset model includes multiple preset sub-models corresponding to the alignment marks. Based on the target property parameters of the material under test in the preset alignment marks and the preset sub-models corresponding to the alignment marks Mx, the simulated alignment signal WQnx of the alignment mark Mx is determined. Based on the actual alignment signal WQ0x and the simulated alignment signal WQnx of each alignment mark Mx in the preset alignment marks, an evaluation function F is established. The evaluation function F is used to characterize the overall deviation between the actual alignment signal WQ0x and the simulated alignment signal WQnx corresponding to each alignment mark Mx in the preset alignment marks. For example, the evaluation function is the sum of the absolute values ​​of the deviations between the actual alignment signal WQ0x and the simulated alignment signal WQnx corresponding to each alignment mark Mx, i.e., the evaluation function is expressed as F = |WQ01-WQn1| + |WQ02-WQn2| + ... + |WQ0x-WQnx|. The target property parameters that make the evaluation function F satisfy preset conditions are obtained as the test property parameters of the material under test.

[0087] In one embodiment, the evaluation function F includes a plurality of intermediate evaluation functions Fx corresponding to the alignment mark. The intermediate evaluation functions characterize the deviation between the actual alignment signal and the simulated alignment signal of the alignment mark. When the deviation corresponding to each of the intermediate evaluation functions is less than or equal to a second preset value, the evaluation function is determined to meet the preset condition.

[0088] For example, the intermediate evaluation function Fx = WQ0x - WQnx. When the absolute value of the deviation corresponding to the intermediate evaluation function of each alignment mark Mx—that is, the deviation between the actual alignment signal WQ0x and the simulated alignment signal WQnx—is less than or equal to a second preset value, the evaluation function is deemed to meet the preset condition. In this case, the target property parameter is the test property parameter of the material under test. This setting avoids the problem of being unable to accurately determine the test property parameter of the material under test when multiple target property parameters cause one intermediate evaluation function to meet the preset condition. For example, the second preset value is 0.

[0089] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the steps or stages in other steps.

[0090] Figure 3 These are schematic diagrams of the structures of the measuring devices for the property parameters of the material under test in some embodiments, such as... Figure 3 As shown, in this embodiment, a device for measuring the property parameters of a material under test is provided. The parts that are the same as or corresponding to those in the embodiments of the above-described method for measuring the property parameters of a material under test will not be repeated below. The device for measuring the property parameters of a material under test includes: a modeling module 302 and a calculation module 304. The modeling module 302 is used to establish a preset model based on preset parameter information of a preset alignment mark. The preset model characterizes the correspondence between the property parameters of the material under test in the preset alignment mark and the preset alignment signal. The preset parameter information includes the geometric information of the preset alignment mark, the refractive index information of the known material in the preset alignment mark, and the extinction coefficient information. The calculation module 304 is used to confirm the simulated alignment signal of the preset alignment mark based on the target property parameters of the material under test in the preset alignment mark and the preset model. Based on the actual alignment signal and the simulated alignment signal of the preset alignment mark, an evaluation function is established, and the target property parameters that satisfy the preset conditions of the evaluation function are obtained as the property parameters to be measured. The evaluation function characterizes the deviation between the actual alignment signal and the simulated alignment signal of the preset alignment mark.

[0091] The geometric information of the preset alignment mark refers to information related to the geometry of the preset alignment mark, including the arrangement information of the film structure composed of known materials and the film structure composed of the material to be measured in the preset alignment mark, the thickness information of each film structure, and the size information of each film structure; the refractive index information of the known material is the refractive index of the known material at the preset wavelength corresponding to the property parameter to be measured, and the extinction coefficient information of the known material is the extinction coefficient of the known material at the preset wavelength corresponding to the property parameter to be measured. For example, the preset wavelength includes at least one of 532nm, 633nm, 780nm, or 852nm.

[0092] The computation module 304 sets the target property parameters of the material under test in the preset alignment mark. Based on vector diffraction theory, and according to the target property parameters and the preset model, it confirms the simulated alignment signal of the preset alignment mark when the measured property parameters of the material under test in the preset alignment mark are the target property parameters. Based on the actual alignment signal and the simulated alignment signal of the preset alignment mark, an evaluation function F is established. The evaluation function F is used to characterize the deviation between the actual alignment signal WQ0 and the simulated alignment signal WQn. For example, the evaluation function F = WQ0 - WQn. The target property parameters that make the evaluation function F satisfy the preset conditions are obtained and used as the measured property parameters of the material under test, thus realizing the measurement of the measured property parameters of the material under test. The preset condition is that the deviation between the actual alignment signal WQ0 and the simulated alignment signal WQn can be ignored. At this time, the target property parameters of the material under test in the preset alignment mark and the measured property parameters of the material under test in the preset alignment mark are equal, and the target property parameters of the material under test at this time can be used as the measured property parameters of the material under test.

[0093] In the aforementioned measurement device for the property parameters of the material under test, the modeling module 302 establishes a preset model based on the preset parameter information of the preset alignment mark. The calculation module 304 confirms the simulated alignment signal of the preset alignment mark based on the target property parameters of the material under test in the preset alignment mark and the preset model. Based on the actual alignment signal and the simulated alignment signal of the preset alignment mark, an evaluation function is established, and the target property parameters that make the evaluation function satisfy preset conditions are obtained as the property parameters to be measured. This measurement device confirms the property parameters to be measured of the material under test by including the actual alignment signal of the preset alignment mark and the preset model of the preset alignment mark, thus realizing the measurement of the property parameters to be measured of the material under test. Furthermore, it boasts high measurement efficiency and low measurement cost.

[0094] Figure 4 This is a schematic diagram of the structure of the measuring device for the property parameters of the material under test in some other embodiments, such as... Figure 4 As shown, in one embodiment, the measuring device for the property parameters of the material under test further includes: a measuring module 306; the measuring module 306 is used to measure the actual alignment signal of the preset alignment mark.

[0095] In one embodiment, the measurement module 306 is further used to measure the actual geometric information of the preset alignment mark; the modeling module 302 establishes the preset model based on the actual parameter information of the preset alignment mark, wherein the actual parameter information includes the actual geometric information, the refractive index information and extinction coefficient information of the known material in the preset alignment mark. This eliminates the influence of process deviations on the preset model and improves the accuracy of measuring the measured property parameters of the material under test, including the measured refractive index and the measured extinction coefficient of the material under test.

[0096] Figure 5 This is a schematic diagram of the structure of the measuring device for the property parameters of the material under test in some other embodiments, such as Figure 5 As shown, in one embodiment, the device for measuring the property parameters of the material under test further includes: an input module 308; the input module 308 is used to input the theoretical geometric information of the preset alignment mark, the refractive index information and extinction coefficient information of the known material in the preset alignment mark; the modeling module 302 establishes the preset model based on the theoretical parameter information of the preset alignment mark, the theoretical parameter information including the theoretical geometric information of the preset alignment mark, the refractive index information and extinction coefficient information of the known material in the preset alignment mark. This eliminates the step of measuring the actual parameter information of the preset alignment mark, improving the rate of measuring the property parameters of the material under test, including the refractive index and extinction coefficient of the material under test.

[0097] In one embodiment, the computing module 304 is further configured to determine the permissible range of the property parameter to be measured, and based on an intelligent algorithm, determine the property parameter to be measured within the permissible range according to the evaluation function. This step narrows the selection range of the target property parameter and improves the efficiency of measuring the property parameter to be measured of the material under test.

[0098] In one embodiment, the calculation module 304 is used to determine that the evaluation function meets a preset condition when the absolute value of the evaluation function is less than or equal to a first preset value. For example, if the first preset value is 0, no prior data acquisition is required during the confirmation of the test property parameters of the material under test, thereby increasing the speed of measuring the test property parameters of the material under test and saving costs.

[0099] In one embodiment, the preset alignment marks include multiple alignment marks including the material under test (TUT). Each alignment mark has a different structure and / or position on the wafer. The computation module 304 is further configured to obtain a simulated alignment signal corresponding to each alignment mark based on the target property parameters and the preset model corresponding to the alignment mark. The evaluation function characterizes the overall deviation between the actual alignment signal and the simulated alignment signal corresponding to each alignment mark in the preset alignment marks. This configuration avoids the problem of inaccurate determination of the TUT property parameters when multiple target property parameters cause the evaluation function to meet preset conditions.

[0100] Specifically, the preset alignment marks include multiple alignment marks with different structures or positions, and the preset model includes multiple preset sub-models corresponding to the alignment marks. The calculation module 304 determines the simulated alignment signal WQnx of the alignment mark Mx based on the target property parameters of the material to be tested in the preset alignment marks and the preset sub-model corresponding to the alignment mark Mx. Based on the actual alignment signal WQ0x and the simulated alignment signal WQnx of each alignment mark Mx in the preset alignment marks, an evaluation function F is established. The evaluation function F is used to characterize the overall deviation between the actual alignment signal WQ0x and the simulated alignment signal WQnx corresponding to each alignment mark Mx in the preset alignment marks. For example, the evaluation function is the sum of the absolute values ​​of the deviations between the actual alignment signal WQ0x and the simulated alignment signal WQnx corresponding to each alignment mark Mx, that is, the evaluation function is expressed as F = |WQ01-WQn1| + |WQ02-WQn2| + ... + |WQ0x-WQnx|. The calculation module 304 obtains the target property parameters that make the evaluation function F satisfy the preset conditions, and uses them as the test property parameters of the material to be tested.

[0101] In one embodiment, the evaluation function F includes a plurality of intermediate evaluation functions Fx corresponding to the alignment mark. The intermediate evaluation functions characterize the deviation between the actual alignment signal and the simulated alignment signal of the alignment mark. When the deviation corresponding to each of the intermediate evaluation functions is less than or equal to a second preset value, the computing module 304 determines that the evaluation function meets the preset condition.

[0102] For example, the intermediate evaluation function Fx = WQ0x - WQnx. The computation module 304 determines that the evaluation function meets the preset condition when the absolute value of the deviation corresponding to the intermediate evaluation function of each alignment mark Mx (i.e., the deviation between the actual alignment signal WQ0x and the simulated alignment signal WQnx) is less than or equal to a second preset value. At this point, the target property parameter is the test property parameter of the material under test. This setting avoids the problem of not being able to accurately determine the test property parameter of the material under test when multiple target property parameters cause one intermediate evaluation function to meet the preset condition. For example, the second preset value is 0.

[0103] Specific limitations regarding the measuring device for the property parameters of the material under test can be found in the limitations on the measuring method for the property parameters of the material under test described above, and will not be repeated here. Each module in the aforementioned measuring device for the property parameters of the material under test can be implemented entirely or partially through software, hardware, or a combination thereof. Each module can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module. It should be noted that the module division in this embodiment is illustrative and only represents a logical functional division; other division methods may be used in actual implementation.

[0104] This disclosure also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method for measuring the property parameters of the material to be tested as described in any of the preceding claims.

[0105] This disclosure discloses a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for measuring the property parameters of the material to be tested as described in any of the preceding claims.

[0106] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0107] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for measuring the property parameters of a material to be tested, characterized in that, include: A preset model is established based on the preset parameter information of the preset alignment mark. The preset model characterizes the correspondence between the test property parameters of the material to be tested in the preset alignment mark and the preset alignment signal of the preset alignment mark. The preset parameter information includes the geometric information of the preset alignment mark, the refractive index information and extinction coefficient information of the known material in the preset alignment mark. Based on the target property parameters of the material to be tested in the preset alignment mark and the preset model, confirm the simulated alignment signal of the preset alignment mark; An evaluation function is established based on the actual alignment signal and the simulated alignment signal of the preset alignment mark. The evaluation function is used to characterize the deviation between the actual alignment signal and the simulated alignment signal. Obtain the target property parameters that make the evaluation function meet the preset conditions, and use them as the property parameters to be tested.

2. The measurement method according to claim 1, characterized in that, Before establishing the preset model based on the preset parameter information of the preset alignment mark, the method further includes: Create a preset alignment mark; The actual geometric information and actual alignment signal of the preset alignment mark are obtained by measurement; The step of establishing a preset model based on preset parameter information of preset alignment marks includes: Establish a preset model based on the actual parameter information of the preset alignment mark; The actual parameter information includes the actual geometric information, the refractive index information and extinction coefficient information of the known material in the preset alignment mark.

3. The measurement method according to claim 1, characterized in that, Before establishing the preset model based on the preset parameter information of the preset alignment mark, the method further includes: Create a preset alignment mark; The actual alignment signal of the preset alignment mark is obtained by measurement; The step of establishing a preset model based on preset parameter information of preset alignment marks includes: A preset model is established based on the theoretical parameter information of the preset alignment mark. The theoretical parameter information includes the theoretical geometric information of the preset alignment mark, the refractive index information and extinction coefficient information of the known materials in the preset alignment mark.

4. The measurement method according to claim 1, characterized in that, Before confirming the simulated alignment signal of the preset alignment mark based on the target property parameters of the material to be tested in the preset alignment mark and the preset model, the process includes: Determine the permissible range of the property parameter to be measured; Select the target property parameters within the permitted range.

5. The measurement method according to claim 1, characterized in that, When the absolute value of the evaluation function is less than or equal to a first preset value, the evaluation function is determined to meet the preset condition.

6. The measurement method according to claim 1, characterized in that, The preset alignment marks include multiple alignment marks comprising the material under test, each alignment mark having a different structure and / or position on the wafer. The step of confirming the simulated alignment signal of the preset alignment marks based on the target property parameters and the preset model includes: Based on the target property parameters and the preset model corresponding to the alignment mark, the simulated alignment signal corresponding to the alignment mark is confirmed; The evaluation function is used to characterize the overall deviation between the actual alignment signal and the simulated alignment signal corresponding to each of the preset alignment marks.

7. The measurement method according to claim 6, characterized in that, The evaluation function includes multiple intermediate evaluation functions corresponding to the alignment mark. The intermediate evaluation function characterizes the deviation between the actual alignment signal and the simulated alignment signal of the alignment mark. When the deviation corresponding to each intermediate evaluation function is less than or equal to a second preset value, the evaluation function is determined to meet the preset condition.

8. The measurement method according to claim 1, characterized in that, The preset alignment mark includes a substrate layer, a pattern layer located on the surface of the substrate layer, and a cover layer located on the surface of the pattern layer. The pattern layer includes a first pattern structure and a second pattern structure disposed adjacent to each other in a direction parallel to the substrate layer. The material of the substrate layer, the first patterned structure, the second patterned structure, or the cover layer includes the material to be tested.

9. A measuring device for the property parameters of a material to be tested, characterized in that, include: A modeling module is used to establish a preset model based on preset parameter information of a preset alignment mark. The preset model characterizes the correspondence between the test property parameters of the material under test in the preset alignment mark and the preset alignment signal. The preset parameter information includes the geometric information of the preset alignment mark, the refractive index information and extinction coefficient information of the known material in the preset alignment mark. The computation module is used to confirm the simulated alignment signal of the preset alignment mark based on the target property parameters of the material to be tested in the preset alignment mark and the preset model, and to establish an evaluation function based on the actual alignment signal and the simulated alignment signal of the preset alignment mark, and to obtain the target property parameters that make the evaluation function meet the preset conditions as the property parameters to be tested. The evaluation function is used to characterize the deviation between the actual alignment signal and the simulated alignment signal of the preset alignment mark.

10. The measuring device according to claim 9, characterized in that, Also includes: A measurement module is used to measure the actual alignment signal of the preset alignment mark.

11. The measuring device according to claim 10, characterized in that, The measurement module is also used to measure the actual geometric information of the preset alignment mark; the modeling module establishes the preset model based on the actual parameter information of the preset alignment mark, wherein the actual parameter information includes the actual geometric information, the refractive index information and extinction coefficient information of the known material in the preset alignment mark.

12. The measuring device according to claim 9, characterized in that, Also includes: The input module is used to input the theoretical geometric information of the preset alignment mark, the refractive index information and extinction coefficient information of the known material in the preset alignment mark; The modeling module establishes the preset model based on the theoretical parameter information of the preset alignment mark. The theoretical parameter information includes the theoretical geometric information of the preset alignment mark, the refractive index information and extinction coefficient information of the known material in the preset alignment mark.

13. The measuring device according to claim 9, characterized in that, The calculation module is used to determine that the evaluation function meets the preset conditions when the absolute value of the evaluation function is less than or equal to a first preset value.

14. The measuring device according to claim 9, characterized in that, The computing module is also used to determine the permissible range of the property parameter to be tested, and based on an intelligent algorithm, determine the property parameter to be tested within the permissible range of the property parameter to be tested according to the evaluation function.

15. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method for measuring the property parameters of the material to be tested according to any one of claims 1 to 8.

16. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method for measuring the property parameters of the material to be tested according to any one of claims 1 to 8.

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