Capacitance value determination method, capacitance calibration method and MOMCAP capacitance modeling method of calibrate test structure

Abstract

The embodiment of the invention provides a capacitance value determination method, a capacitance calibration method and an MOMCAP capacitance modeling method of a calibration test structure. The capacitance value determination method comprises the following steps: acquiring a test object comprising a plurality of groups of calibration structures, wherein the calibration structures are associated with the same MOMCAP standard test structure; selecting a plurality of groups of representative calibration structures from the plurality of groups of calibration structures according to a specific parameter combination; carrying out capacitance value testing on each group of selected calibration structures to obtain corresponding actually measured capacitance value data; based on the actually measured capacitance value data, analyzing and determining a function relationship between the calibration capacitance value and the selected parameter; and calculating capacitance values of other calibration structures with different parameter combinations by using the function relationship. According to the embodiment of the invention, the method efficiently obtains the call data of the MOMCAP capacitor, reduces the occupied area of a chip, reduces the test pressure, and improves the modeling efficiency of a device.

Description

Technical Field

[0001] The present application belongs to the field of semiconductor design SPICE modeling technology, and in particular to a capacitance value determination method of a calibration test structure, a capacitance calibration method, and a MOMCAP capacitance modeling method. Background Art

[0002] MOMCAP, which is the abbreviation of Metal-Oxide-Metal Capacitor, is a component commonly found in semiconductor devices. The main function of this device is to store charge or be used as a filter. It has wide application value in the fields of analog circuits and radio frequency circuits. The accuracy of the MOMCAP capacitance model has a decisive influence on the accuracy of the circuit simulation results, and thus has a significant effect on the actual performance of the circuit. The MOMCAP capacitance modeling process must be based on calibrated data. Usually, the MOMCAP test component includes a standard (normal) structure and a calibration (calibration) structure. The calibration structure is based on the standard structure, removing the MOMCAP main body and retaining only the metal connection line part, the purpose of which is to eliminate the influence of parasitic capacitance effects. The calibrated data can be obtained by subtracting the capacitance values ​​of the standard structure and the calibration structure.

[0003] For the calibration method of MOMCAP capacitors, the currently commonly used strategy is to equip each MOMCAP standard structure with a corresponding calibration structure. However, this approach will lead to excessive occupation of chip area and waste of later test resources. Therefore, how to efficiently obtain the calibration data of MOMCAP capacitors has become a key issue to be solved by those skilled in the art. Summary of the invention

[0004] The solutions provided in this application are as follows:

[0005] A method for determining a capacitance value of a calibration test structure, comprising:

[0006] Obtaining a test object including a plurality of sets of calibration structures associated with the same MOMCAP standard test structure;

[0007] Selecting a number of representative calibration structures from the plurality of calibration structures according to a specific parameter combination;

[0008] Performing capacitance value tests on each selected group of calibration structures to obtain corresponding measured capacitance value data;

[0009] Based on these measured capacitance value data, analyze and determine the functional relationship between the calibration capacitance value and the selected parameters;

[0010] By using the functional relationship, the capacitance values ​​of other calibration structures with different parameter combinations are calculated.

[0011] Optionally, the acquiring of a test object comprising a plurality of groups of calibration structures, wherein the calibration structures are associated with the same MOMCAP standard test structure, comprises: acquiring a test object, wherein the test object comprises at least several groups of calibration structures, wherein the several groups of calibration structures are associated with the same MOMCAP normal test structure.

[0012] Optionally, the acquiring of a test object comprising multiple groups of calibration structures, which are associated with the same MOMCAP standard test structure, includes: selecting the following first group of calibration structures, second group of calibration structures, third group of calibration structures, and fourth group of calibration structures from the several groups of calibration structures, wherein the first group of calibration structures is a combination of calibration structures having maximum L and maximum NF, the second group of calibration structures is a combination of calibration structures having minimum L and minimum NF, the third group of calibration structures is a combination of calibration structures having maximum L and minimum NF, and the fourth group of calibration structures is a combination of calibration structures having minimum L and maximum NF.

[0013] Optionally, the acquiring includes a test object comprising multiple groups of calibration structures, which are associated with the same MOMCAP standard test structure, including: performing capacitance value tests on the first group of calibration structures, the second group of calibration structures, the third group of calibration structures, and the fourth group of calibration structures, respectively, to obtain first measured capacitance value data, second measured capacitance value data, third measured capacitance value data, and fourth measured capacitance value data.

[0014] Optionally, the acquiring includes a test object comprising multiple sets of calibration structures, which are associated with the same MOMCAP standard test structure, including: determining a functional relationship between the calibration capacitance value and L and NF based on the first measured capacitance value data, the second measured capacitance value data, the third measured capacitance value data, and the fourth measured capacitance value data.

[0015] Optionally, the acquiring of a test object comprising a plurality of groups of calibration structures associated with the same MOMCAP standard test structure includes: calculating capacitance values ​​of calibration structures of other sizes in the plurality of groups of calibration structures based on a functional relationship between the calibration capacitance value and L and NF.

[0016] A capacitance calibration method, comprising:

[0017] Obtain the capacitance value of the MOMCAP standard test structure and the capacitance values ​​of several groups of calibration structures corresponding thereto, wherein the capacitance values ​​of the several groups of calibration structures are calculated based on any method of the present application;

[0018] Based on the difference between the capacitance value of the MOMCAP standard test structure and the capacitance values ​​of several groups of calibration structures corresponding thereto, the calibrated capacitance value is calculated.

[0019] A MOMCAP capacitor modeling method, comprising:

[0020] Obtaining a calibrated capacitance value of the MOMCAP, wherein the calibrated capacitance value of the MOMCAP is calculated based on the method of claim 7;

[0021] The MOMCAP capacitance model is obtained by performing MOMCAP capacitance modeling based on the calibrated capacitance value of the MOMCAP.

[0022] A circuit simulation method, comprising:

[0023] Performing MOMCAP capacitance modeling based on the calibrated capacitance value of the MOMCAP to obtain a MOMCAP capacitance model, wherein the calibrated capacitance value of the MOMCAP is calculated based on the method described in the embodiment of the present application;

[0024] Based on the MOMCAP capacitor model, circuit simulation is performed.

[0025] A circuit simulation system, comprising: a simulation host, wherein the simulation host is used to perform MOMCAP capacitance modeling based on the calibrated capacitance value of the MOMCAP to obtain a MOMCAP capacitance model, and to perform circuit simulation based on the MOMCAP capacitance model, wherein the calibrated capacitance value of the MOMCAP is calculated based on the method described in the embodiment of the present application.

[0026] The embodiment of the present application has at least the following technical advantages:

[0027] (1) After obtaining a test object containing multiple groups of calibration structures, several representative groups of calibration structures will be selected from them according to specific parameter combinations. This step does not require subsequent capacitance value testing and other operations to be performed on all calibration structures, but rather through reasonable screening, some structures that can represent the overall situation to a certain extent are found, thereby avoiding the processing of a large number of redundant calibration structures, and greatly reducing the number of calibration structures actually involved in the subsequent process, which means that only a small number of calibration test structures are needed to carry out effective calibration work.

[0028] (2) The calibration structure is a part located on the chip for testing and analyzing capacitance calibration. Generally, more calibration structures will inevitably occupy a larger chip area. However, the present technical solution reduces the number of calibration structures actually required by selecting representative calibration structures as described above. Now, only a small number of representative calibration structures that have been screened out need to be laid out to meet the calibration requirements. Accordingly, the layout area of ​​these calibration structures on the chip will be significantly reduced, thereby achieving the effect of reducing the chip area occupied.

[0029] (3) The test cost is largely related to the number of calibration structures that need to be tested and the amount of test data generated. Each calibration structure requires a certain amount of equipment, time, manpower and other resources to perform operations such as capacitance value testing. When the number of calibration structures actually involved in the test is reduced by selecting representative calibration structures as mentioned above, the various resources required in the test process are directly reduced. For example, the use time of the test equipment will be shortened, and the workload of manual operation and monitoring will also be reduced, thereby effectively reducing the overall test cost.

[0030] (4) After the capacitance values ​​of the selected representative calibration structures are tested and the measured capacitance value data is obtained, the functional relationship between the calibration capacitance value and the selected parameters is further analyzed and determined. With this functional relationship, the capacitance values ​​of other calibration structures with different parameter combinations can be inferred. This means that there is no need to conduct actual tests on all calibration structures with different parameter combinations to obtain capacitance values ​​for modeling. The traditional method requires testing a large number of calibration structures with different parameters one by one to obtain enough data to build an accurate model. This solution greatly shortens the time to obtain comprehensive capacitance value data for modeling by establishing a functional relationship for inference, thereby effectively improving the efficiency of MOMCAP modeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The figure is a flow chart of a method for determining the capacitance value of a calibration test structure according to an embodiment of the present application.

[0032] Figure 2This is the MOMCAP normal and calibration structure size information in a specific scenario of this application.

[0033] Figure 3 This is a flow chart of a capacitance calibration method according to an embodiment of the present application.

[0034] Figure 4 This is a flow chart of a MOMCAP capacitor modeling method according to an embodiment of the present application.

[0035] Figure 5 A schematic diagram of a flow chart of a circuit simulation method according to an embodiment of the present application. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0037] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0038] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

[0039] Figure 1 FIG. 1 is a flow chart of a method for determining the capacitance value of a calibration test structure according to an embodiment of the present application. Figure 1 As shown, the method for determining the capacitance value of the calibration test structure includes:

[0040] Acquire a test object including a plurality of sets of calibration structures, the calibration structures being associated with the same MOMCAP standard test structure;

[0041] Selecting a number of representative calibration structures from the plurality of calibration structures according to a specific parameter combination;

[0042] Performing capacitance value tests on each selected group of calibration structures to obtain corresponding measured capacitance value data;

[0043] Based on these measured capacitance value data, analyze and determine the functional relationship between the calibration capacitance value and the selected parameters;

[0044] By using the functional relationship, the capacitance values ​​of other calibration structures with different parameter combinations are calculated.

[0045] The embodiment of the present application has at least the following technical advantages:

[0046] (1) After obtaining a test object containing multiple groups of calibration structures, several representative groups of calibration structures will be selected from them according to specific parameter combinations. This step does not require subsequent capacitance value testing and other operations to be performed on all calibration structures, but rather through reasonable screening, some structures that can represent the overall situation to a certain extent are found, thereby avoiding the processing of a large number of redundant calibration structures, and greatly reducing the number of calibration structures actually involved in the subsequent process, which means that only a small number of calibration test structures are needed to carry out effective calibration work.

[0047] (2) The calibration structure is a part located on the chip for testing and analyzing capacitance calibration. Generally, more calibration structures will inevitably occupy a larger chip area. However, the present technical solution reduces the number of calibration structures actually required by selecting representative calibration structures as described above. Now, only a small number of representative calibration structures that have been screened out need to be laid out to meet the calibration requirements. Accordingly, the layout area of ​​these calibration structures on the chip will be significantly reduced, thereby achieving the effect of reducing the chip area occupied.

[0048] (3) The test cost is largely related to the number of calibration structures that need to be tested and the amount of test data generated. Each calibration structure requires a certain amount of equipment, time, manpower and other resources to perform operations such as capacitance value testing. When the number of calibration structures actually involved in the test is reduced by selecting representative calibration structures as mentioned above, the various resources required in the test process are directly reduced. For example, the use time of the test equipment will be shortened, and the workload of manual operation and monitoring will also be reduced, thereby effectively reducing the overall test cost.

[0049] (4) After the capacitance values ​​of the selected representative calibration structures are tested and the measured capacitance value data is obtained, the functional relationship between the calibration capacitance value and the selected parameters is further analyzed and determined. With this functional relationship, the capacitance values ​​of other calibration structures with different parameter combinations can be inferred. This means that there is no need to conduct actual tests on all calibration structures with different parameter combinations to obtain capacitance values ​​for modeling. The traditional method requires testing a large number of calibration structures with different parameters one by one to obtain enough data to build an accurate model. This solution greatly shortens the time to obtain comprehensive capacitance value data for modeling by establishing a functional relationship for inference, thereby effectively improving the efficiency of MOMCAP modeling.

[0050] Optionally, the acquiring of a test object comprising a plurality of groups of calibration structures, wherein the calibration structures are associated with the same MOMCAP standard test structure, comprises: acquiring a test object, wherein the test object comprises at least several groups of calibration structures, wherein the several groups of calibration structures are associated with the same MOMCAP normal test structure.

[0051] In the specific implementation, for example, wafers or chips at a specific stage are selected from the chip production process line where MOMCAP capacitors are being manufactured as the initial source of the test object. For example, after completing the basic lithography, etching and other key process steps of the MOMCAP capacitor, but before the subsequent packaging and other processing, some samples are selected as test objects. This ensures that the selected test objects can accurately reflect the true state of the MOMCAP capacitor and related calibration structures in the actual production environment. In addition, a batch of wafers for testing purposes can be specially made, and MOMCAP capacitors and multiple sets of calibration structures associated therewith can be laid out on these wafers according to predetermined design rules. This special test wafer can more flexibly control the parameter setting, distribution, etc. of the calibration structure, so as to better meet different testing needs and research purposes.

[0052] In addition, according to the detailed layout design rules formulated by the chip design team, professional electronic design automation (EDA) tools are used to generate a test object layout containing multiple sets of calibration structures and the same MOMCAP standard test structure. During the layout design process, the location, size, connection relationship, etc. of the calibration structure and the standard test structure must be accurately planned. For example, ensure that the calibration structure has a reasonable distance from the standard test structure in physical position, which is convenient for subsequent test operations (such as probe contact, etc.) and does not cause mutual interference (such as electromagnetic coupling, etc.) due to being too close.

[0053] Furthermore, in the process of generating the test object, appropriate process parameters are set according to the performance requirements and expected application scenarios of the target MOMCAP capacitor. These process parameters include but are not limited to photolithography accuracy, etching depth, metal layer thickness, etc., which will directly affect the electrical characteristics of the MOMCAP capacitor and the calibration structure. For example, for MOMCAP capacitor calibration with high precision requirements, finer photolithography accuracy may be required to ensure the dimensional accuracy of the calibration structure and the standard test structure, thereby improving the accuracy of capacitance value measurement.

[0054] Exemplarily, some calibration structures can establish direct electrical connection associations by sharing certain electrodes or nodes with MOMCAP standard test structures. For example, some calibration structures may share ground electrodes with standard test structures, so that when performing capacitance value tests, the capacitance values ​​of each calibration structure and standard test structure can be accurately determined by measuring the potential difference between different nodes and known electrical parameters (such as current, etc.), using the basic calculation formula of capacitance (such as C=Q / V). The calibration structure can also be electrically connected in series or in parallel with the MOMCAP standard test structure. For example, a group of calibration structures are connected in series with the standard test structure, and the capacitance value information of each structure is obtained by analyzing the total capacitance, voltage division and other characteristics of the series circuit during the test; or a parallel connection method is adopted to determine the capacitance value of the calibration structure and the standard test structure according to the total capacitance calculation formula of the parallel circuit and the current distribution of each branch.

[0055] Optionally, on the chip layout, the calibration structure is usually arranged in the vicinity of the MOMCAP standard test structure. The advantage of doing so is that it is convenient to use the same set of test equipment (such as a probe station, etc.) to perform fast and convenient test operations during the test process. For example, multiple calibration structures are surrounded by regular shapes such as rings or matrices around the standard test structure, so that the probe can test the capacitance value of each structure in turn without frequently changing the test position, thereby improving the test efficiency.

[0056] In order to facilitate analysis and comparison, some calibration structures can be laid out symmetrically with the MOMCAP standard test structure. For example, calibration structures can be laid out in symmetrical positions such as the top and bottom, left and right of the standard test structure. In this way, during the test process, by comparing the capacitance value differences of the calibration structures in symmetrical positions, possible process deviations or other abnormalities can be quickly discovered, which helps to improve the accuracy and reliability of the test.

[0057] After the test object is generated, an optical microscope can also be used to inspect its appearance. Check whether there are obvious defects on the surface of the calibration structure and the MOMCAP standard test structure, such as scratches, stains, photolithography residues, etc. These surface defects may affect the subsequent electrical test results. For example, scratches may change the effective area of ​​the electrode, resulting in inaccurate capacitance value measurement. In addition, use electrical test equipment (such as a multimeter, etc.) to perform preliminary electrical performance tests on the test object. Mainly check whether there are abnormal conditions such as short circuits or open circuits between the various structures. For example, by measuring the resistance values ​​between different nodes, it is determined whether there is an unexpected low resistance (short circuit) or high resistance (open circuit) to ensure that the electrical connection of the test object is normal before the formal capacitance value test is performed. When designing the layout of the test object, suitable probe contact points should be designed specifically for the calibration structure and the MOMCAP standard test structure. These contact points should have good conductivity, stability and repeatability. For example, gold plating and other processes are used to process the probe contact points to improve their conductivity. At the same time, the size and shape of the contact points must be suitable for accurate contact of the probe to avoid poor contact during the test process, which affects the accurate measurement of the capacitance value. Design the transmission path of the test signal in the test object to ensure that the test signal can accurately and stably reach each calibration structure and MOMCAP standard test structure. For example, low-impedance metal wiring is used to transmit the test signal to avoid signal attenuation or distortion during the transmission process, thereby ensuring that when performing a capacitance value test, the correct capacitance value result can be obtained based on the accurate test signal.

[0058] Optionally, the acquiring of a test object comprising multiple groups of calibration structures, which are associated with the same MOMCAP standard test structure, includes: selecting the following first group of calibration structures, second group of calibration structures, third group of calibration structures, and fourth group of calibration structures from the several groups of calibration structures, wherein the first group of calibration structures is a combination of calibration structures having maximum L and maximum NF, the second group of calibration structures is a combination of calibration structures having minimum L and minimum NF, the third group of calibration structures is a combination of calibration structures having maximum L and minimum NF, and the fourth group of calibration structures is a combination of calibration structures having minimum L and maximum NF.

[0059] In the specific implementation, the measurement method and the specific range involved of the MOMCAP finger length L are defined. For example, L can be the length value measured from one end of the finger structure to the other end along a specific direction (such as horizontal or vertical direction, which needs to be clearly specified), and the measurement unit may be nanometers or microns, etc. It reflects the extension degree of the finger in physical size, and has a certain influence on the performance of the capacitor (such as capacitance value, equivalent series resistance, etc.). In addition, the statistical rules for the number of MOMCAP fingers NF are defined. NF refers to the number of valid fingers that can be clearly defined in the entire MOMCAP calibration structure. For example, it is specified which parts of the finger structure should be included in the NF, excluding some finger parts that may not participate in the main influence of the capacitor performance due to imperfect processes or special design requirements, to ensure that the statistics of NF are accurate and consistent.

[0060] During the chip design phase, the design files generated by professional electronic design automation (EDA) tools will contain detailed design information for each calibration structure. For example, for the L parameter, the set values ​​for the finger length can be extracted from the design file, which are determined based on design requirements and layout planning. For the NF parameter, the layout diagram of the finger structure and related annotation information can be obtained from the design file, and the NF value of each calibration structure can be accurately calculated manually or automatically (based on preset statistical rules).

[0061] After the chip is manufactured, the actual calibration structure needs to be measured to verify and obtain more accurate L and NF parameter values. For the L parameter, a high-precision microscope combined with image analysis software can be used to measure the actual length of the finger. By processing the finger image taken by the microscope, the boundary of the finger is identified, and then its length is accurately measured to calibrate the estimated value based on the design file. For the NF parameter, the finger structure can be carefully observed under a microscope, and the NF value can be reconfirmed according to the established statistical rules to ensure its accuracy. At the same time, it can also detect abnormal finger conditions caused by possible manufacturing defects (such as one more or one less finger, etc.).

[0062] When screening the first group of calibration structures (calibration structure combinations with maximum L and maximum NF), collect relevant information of all calibration structures, and organize the L value (interdigitation length) and NF value (number of interdigitation fingers) of each calibration structure into a database or spreadsheet. Each row represents a calibration structure, in which two columns record the L value and NF value respectively, and other columns can also record auxiliary information such as the number of the calibration structure and the position on the chip. Perform a preliminary check on the collected data to ensure that the L value and NF value are recorded accurately and there is no missing data or obvious error. For example, check whether the L value is within a reasonable length range (according to the design expectation) and whether the NF value is a positive integer and meets the statistical rules. Further, sort the L value column in the sorted data table in descending order, which is achieved by a database query statement or the sorting function of a spreadsheet. In this way, the rows where the calibration structures with the largest L values ​​are located can be quickly found. In the set of calibration structures with the largest L values ​​found, the NF value column is sorted in descending order. The corresponding functions of the database or spreadsheet can also be used. After this step, the calibration structure combination at the front of the sorting result is the calibration structure with the largest L and the largest NF, that is, the first group of calibration structures.

[0063] -Once the first set of calibration structures are determined, the areas where these calibration structures are located should be clearly marked on the chip layout. This can be done by drawing special color borders or marking special symbols on the layout so that they can be quickly identified during subsequent testing and analysis. At the same time, in the database or related test record documents, the various information of the first set of calibration structures should be recorded in detail, including the calibration structure number, specific location, corresponding L value and NF value, etc. These records will facilitate subsequent separate testing, analysis and comparative study of this set of calibration structures with other sets of calibration structures.

[0064] When screening the second group of calibration structures (calibration structure combination with minimum L and minimum NF), just like screening the first group of calibration structures, first organize the L values ​​and NF values ​​of all calibration structures into a database or spreadsheet, and conduct a preliminary check to ensure the accuracy and completeness of the data. Sort the L value column in the data table in ascending order, and find the rows where the calibration structures with the smallest L values ​​are located through the database query statement or the sorting function of the spreadsheet. In the set of calibration structures with the smallest L values ​​found, sort the NF value column in ascending order. After these two sorting operations, the calibration structure combination at the front of the sorting results is the calibration structure with the smallest L and the smallest NF, that is, the second group of calibration structures. Mark the area where the second group of calibration structures are located on the chip layout, and a different marking method can be used from the first group of calibration structures, such as a different color border or a different symbol to distinguish different groups of calibration structures. In the database or related test record documents, record the various information of the second group of calibration structures in detail, including the number of the calibration structure, the specific location, the corresponding L value and NF value, etc., for subsequent use.

[0065] When screening the third group of calibration structures (calibration structure combinations with maximum L and minimum NF), organize the L values ​​and NF values ​​of all calibration structures into a database or spreadsheet, and perform a preliminary check to ensure that the data is accurate. Sort the L value column in the data table in descending order to find the rows where the calibration structures with the largest L values ​​are located. In the set of calibration structures with the largest L values ​​found, sort the NF value column in ascending order. After these two sorting operations, the calibration structure combination at the front of the sorting results is the calibration structure with the largest L and the smallest NF, that is, the third group of calibration structures. Mark the area where the third group of calibration structures are located on the chip layout, and a new marking method, such as a specific pattern or color, can be used to distinguish different groups of calibration structures. In the database or related test record documents, record each information of the third group of calibration structures in detail, including the calibration structure number, specific location, corresponding L value and NF value, etc., for subsequent use.

[0066] When screening the fourth group of calibration structures (calibration structure combinations with minimum L and maximum NF), organize the L and NF values ​​of all calibration structures into a database or spreadsheet and perform a preliminary check to ensure that the data is accurate. Sort the L value column in the data table in ascending order to find the rows where the calibration structures with the smallest L values ​​are located. In the set of calibration structures with the smallest L values ​​found, sort the NF value column in descending order. After these two sorting operations, the calibration structure combination at the top of the sorting results is the calibration structure with the smallest L and the largest NF, that is, the fourth group of calibration structures. Mark the area where the fourth group of calibration structures are located on the chip layout, and unique colors or symbols can be used to distinguish different groups of calibration structures. In the database or related test record documents, record each information of the fourth group of calibration structures in detail, including the calibration structure number, specific location, corresponding L value and NF value, etc., for subsequent use.

[0067] To this end, selecting the above-mentioned specific four groups of calibration structures from several groups of calibration structures has technical benefits:

[0068] (1) By selecting the first group of calibration structures with maximum L and maximum NF, the second group of calibration structures with minimum L and minimum NF, the third group of calibration structures with maximum L and minimum NF, and the fourth group of calibration structures with minimum L and maximum NF, the boundaries and typical combinations of the two key parameters of MOMCAP finger length (L) and number of fingers (NF) can be fully covered. This means that in subsequent related analyses such as capacitor calibration, based on these representative calibration structure combinations, the variation law of capacitor performance under different parameter values ​​can be more accurately understood, whether in the extreme case of a long finger length and a large number of fingers (the first group), or in the other extreme case of a short finger length and a small number of fingers (the second group), as well as different combinations of the two parameters of one long and one short, one more and one less (the third and fourth groups), can be fully examined.

[0069] (2) After these four groups of calibration structures are screened out, they can be easily compared between different groups when conducting relevant electrical performance analysis such as capacitance value testing and equivalent series resistance measurement. For example, the capacitance value difference between the first group (maximum L and maximum NF) and the second group (minimum L and minimum NF) calibration structures can be directly compared, and the impact of the significant changes in the length and number of fingers on the capacitance performance can be clearly observed; similarly, by comparing the third group and the fourth group, or cross-comparing other groups with these two groups, the specific performance of different parameter combinations in capacitance performance can be studied in more depth, which helps to quickly locate which parameters have a more critical impact on capacitance performance, thereby providing a strong basis for optimizing MOMCAP design.

[0070] (3) Among the numerous calibration structures, only these four groups of calibration structures with specific parameter combinations are selected for focused analysis, rather than conducting comprehensive and in-depth testing and analysis on all calibration structures, which can greatly reduce the number of calibration structures actually involved in the subsequent complex test process. This means that a lot of test time, equipment resources, and labor costs can be saved, making the entire MOMCAP capacitor calibration process more efficient, obtaining key data sufficient for accurate calibration and modeling in a shorter time, and improving the overall efficiency of the calibration work.

[0071] (4) The different parameter combinations represented by these four sets of calibration structures provide rich and representative sample data for the modeling of MOMCAP capacitors. By performing capacitance value tests on the calibration structures with different parameter combinations and establishing a relationship model between capacitance performance and parameters such as finger length and number of fingers based on the test results, since a variety of typical parameter conditions are covered, the established model can more accurately reflect the actual situation of actual capacitance performance changing with parameter changes, thereby improving the accuracy of MOMCAP capacitor modeling and making subsequent predictions, design optimization, and other work based on the model more reliable.

[0072] (5) In the chip manufacturing process, process deviations are inevitable, and these deviations may affect the performance of MOMCAP capacitors. By screening out these four groups of calibration structures with different parameter combinations, if it is found that the capacitor performance of a certain group of calibration structures is significantly different from theoretical expectations during testing and analysis, it is possible to more specifically explore which specific parameter combinations, such as larger or smaller finger lengths, more or fewer finger numbers, have a more significant impact on capacitor performance, thereby helping chip manufacturing process personnel to promptly discover and correct process deviations and improve chip manufacturing quality.

[0073] Optionally, the acquiring includes a test object comprising multiple groups of calibration structures, which are associated with the same MOMCAP standard test structure, including: performing capacitance value tests on the first group of calibration structures, the second group of calibration structures, the third group of calibration structures, and the fourth group of calibration structures, respectively, to obtain first measured capacitance value data, second measured capacitance value data, third measured capacitance value data, and fourth measured capacitance value data.

[0074] In a specific implementation, the first group of calibration structures, the second group of calibration structures, the third group of calibration structures, and the fourth group of calibration structures are respectively tested for capacitance values, and obtaining first measured capacitance value data, second measured capacitance value data, third measured capacitance value data, and fourth measured capacitance value data may include the following process:

[0075] (1) According to the characteristics of MOMCAP capacitors and the required test accuracy, select a professional capacitance tester, such as an LCR tester (inductance, capacitance, resistance tester). This type of instrument can accurately measure capacitance values ​​and can operate at different test frequencies to adapt to the various frequency conditions that MOMCAP capacitors may face in actual application scenarios.

[0076] Ensure that the selected tester has a sufficiently high measurement accuracy. For example, for high-precision MOMCAP capacitance calibration, the accuracy of the tester should reach a resolution of picofarads (pF) or even smaller to accurately obtain the capacitance value of each calibration structure.

[0077] (2) Before the formal test, the selected capacitance tester needs to be calibrated. Use a calibration piece with a known standard capacitance value and follow the calibration process provided by the instrument manufacturer. This usually includes connecting the calibration piece to the test port of the tester, setting the corresponding test parameters (such as test frequency, etc.) to be consistent with the nominal parameters of the calibration piece, and then starting the calibration procedure so that the tester automatically adjusts the internal parameters to achieve accurate measurement.

[0078] Recalibrate the tester regularly to ensure the continuity of measurement accuracy. The calibration cycle can be determined based on the frequency of use of the instrument, environmental conditions and other factors. It is generally recommended to recalibrate at regular intervals (such as weekly or monthly, depending on the situation) or when the instrument is moved or the ambient temperature and humidity change significantly.

[0079] (3) Use a high-precision probe station as a medium to connect the test instrument and the calibration structure. The probe station should have precise positioning capabilities to accurately place the probes on the corresponding test points of each calibration structure on the chip.

[0080] Clean and maintain the probe station to ensure that there are no impurities or oxide layers on the probe surface, so as not to affect the good electrical connection between the probe and the calibration structure. Use special cleaning tools and reagents, such as a cotton swab dipped in an appropriate amount of alcohol solution to wipe the probe clean.

[0081] (4) Determine the appropriate connection method based on the layout of the calibration structure on the chip and the interface type of the test instrument. For each group of calibration structures (the first group, the second group, the third group, and the fourth group), electrical connection is usually established by directly contacting the probe with the electrode of the calibration structure.

[0082] For example, if the electrodes of the calibration structure are designed in the form of metal pads, the probe tip is accurately aligned and gently pressed on the corresponding pad to ensure a stable, low-impedance electrical connection between the probe and the pad. During the connection process, care should be taken to avoid physical damage to the calibration structure, such as scratching the electrodes and crushing the fingers.

[0083] (5) Select a suitable test frequency range based on the application scenario and design requirements of the MOMCAP capacitor. Generally speaking, you can first refer to the expected operating frequency range of the MOMCAP capacitor in the chip design document, and on this basis, select multiple representative test frequency points for testing. For example, if the MOMCAP capacitor is mainly used in RF circuits in a specific frequency band, you can select several equally spaced frequency points around the frequency band, such as selecting a frequency point near the lower limit, middle value, and upper limit of the frequency band for testing.

[0084] Common test frequencies may range from tens of kilohertz (kHz) to hundreds of megahertz (MHz), depending on the specific application of the MOMCAP capacitor. By testing at different frequencies, a more comprehensive understanding of how the capacitance characteristics of each calibration structure change with frequency can be obtained.

[0085] (6) In addition to the test frequency, other relevant parameters of the tester need to be set. For example, when setting the measurement mode, you can select the automatic measurement mode to allow the tester to automatically complete the measurement and recording of the capacitance value according to the preset frequency and other parameters; set the measurement accuracy to ensure that the tester can measure with the required accuracy, such as setting the accuracy to a few decimal places (determined according to actual needs); set the test voltage, generally select the appropriate test voltage value according to the rated voltage range of the MOMCAP capacitor to avoid the accuracy of the test results being affected by too high or too low voltage.

[0086] (7) According to the predetermined order, the capacitance value of the first group of calibration structures is tested first. The probes of the probe station are accurately connected to the corresponding electrodes of the first group of calibration structures. After setting the various parameters of the tester, the test program is started. The tester will automatically measure and record the capacitance values ​​of the first group of calibration structures at different test frequencies to form the first measured capacitance value data.

[0087] After completing the test of the first group of calibration structures, the same operation is performed on the second, third, and fourth groups of calibration structures in turn to obtain the second measured capacitance value data, the third measured capacitance value data, and the fourth measured capacitance value data, respectively. During the test process, it is necessary to ensure that the probe is well connected to the calibration structure before each test, and disconnect it in time after the test to avoid unnecessary electrical interference.

[0088] (8) During the test, the tester will automatically record the measured capacitance data. At the same time, arrange for a dedicated person or use an automatic monitoring system to monitor the test process to ensure the accuracy and completeness of the test data. For example, observe whether the measured value displayed on the tester's display screen or the monitoring software interface is within a reasonable range, and whether there are abnormal fluctuations. If abnormal data is found, the test should be stopped immediately, and whether there are any problems in the test connection, instrument settings, etc., and the test should be repeated after the problem is resolved.

[0089] (9) In order to ensure the reliability of the test results, the capacitance value test of each set of calibration structures is repeated. That is, after the first test is completed, the capacitance value test of each set of calibration structures is repeated under the same test conditions (including test equipment, connection method, parameter setting, etc.).

[0090] Compare the measured capacitance data obtained from the two tests. If the difference between the two data is within an acceptable error range (determined according to industry standards or specific project requirements), the test result is reliable and can be used as a basis for subsequent analysis and processing. If the difference exceeds the error range, it is necessary to further check whether there are any problems with the test equipment, connection method, parameter setting, etc., and retest until a reliable test result is obtained.

[0091] (10) According to the theoretical design model of MOMCAP capacitor, the theoretical capacitance value of each calibration structure under the corresponding test conditions is calculated. The measured capacitance value data is compared with the theoretical value to analyze the cause of the difference. If the measured value differs greatly from the theoretical value, it may be caused by manufacturing process deviation, test equipment error, improper test condition setting, etc. Through this comparative analysis, the accuracy of the test results can be further verified and a reference can be provided for subsequent analysis and processing.

[0092] Optionally, the acquiring includes a test object comprising multiple sets of calibration structures, which are associated with the same MOMCAP standard test structure, including: determining a functional relationship between the calibration capacitance value and L and NF based on the first measured capacitance value data, the second measured capacitance value data, the third measured capacitance value data, and the fourth measured capacitance value data.

[0093] To this end, based on the first measured capacitance value data, the second measured capacitance value data, the third measured capacitance value data, and the fourth measured capacitance value data, the process of determining the functional relationship between the calibration capacitance value and L and NF is as follows:

[0094] (1) Collect and summarize the first measured capacitance value data, the second measured capacitance value data, the third measured capacitance value data, and the fourth measured capacitance value data obtained by respectively testing the capacitance value of the first group, the second group, the third group, and the fourth group of calibration structures. These data can be stored in a spreadsheet software (such as Excel), with each group of data occupying a row, and the column headings are calibration structure group number, measured capacitance value, L value (MOMCAP finger length), NF value (MOMCAP finger number) and other related information, so as to facilitate subsequent analysis and processing.

[0095] (2) Check whether there are outliers or erroneous data in the collected data. Outliers may be capacitance values ​​that are significantly deviated from the normal range due to accidental interference during the test, equipment failure, etc. For such outliers, they can be identified by observing the distribution of the data (such as drawing a scatter plot or other visual means) or by setting a reasonable range based on industry experience. Once an outlier is found, decide whether to remove the data point based on the specific situation. For example, if the outlier is caused by a momentary failure of the test equipment and the failure has been confirmed and repaired, then the outlier can be removed; if the cause of the outlier is uncertain, it may be necessary to retest the corresponding calibration structure to obtain accurate data.

[0096] (3) In order to facilitate the subsequent data analysis and function relationship fitting, the collected measured capacitance data, L value and NF value are standardized. For the capacitance data, it can be scaled according to a certain ratio so that it is in a numerical range that is more convenient for calculation and analysis, such as converting the capacitance value into a relative value with a unit of picofarad (pF) and a value between 0 and 1 (the specific conversion method can be determined according to the actual data situation). For the L value and NF value, they can also be appropriately scaled or transformed according to their respective value ranges, such as converting the L value from micrometers to millimeters, or performing a logarithmic transformation on the NF value, etc., to facilitate the numerical balance between different parameters and subsequent function fitting operations.

[0097] (4) According to the physical principle of MOMCAP capacitor, a functional relationship is constructed in the form of C(L,NF)=A*(NF*B+C) / L. Here, the finger length (L) is similar to a certain equivalent concept of the plate spacing, the number of fingers (NF) affects the equivalent of the plate area, and the coefficients A, B, and C may be related to other factors such as dielectric constant and material properties. For example, A may be related to the dielectric constant of the capacitor material and some overall proportionality coefficients, B may be related to the proportionality coefficient of the finger structure's contribution to the plate area, and C may be related to some basic capacitance value contribution parts (parts that do not depend on the number and length of fingers). C(L,NF) represents the fitted capacitance value.

[0098] (5) For the given function relationship $C(L,NF)=A*(NF*B+C) / L$, since it is not a simple linear function relationship, it is necessary to select a suitable nonlinear fitting method, such as the nonlinear fitting extension based on the least squares method (such as the Levenberg-Marquardt algorithm, etc.), genetic algorithm, particle swarm optimization algorithm, etc. These methods can find the optimal parameter value combination in the nonlinear function space so that the fitting effect between the fitting function and the measured data points is the best. When selecting a specific method, factors such as the characteristics of the data, computing resources, and the accuracy requirements of the fitting need to be considered. For example, if the amount of data is relatively small and the requirements for fitting accuracy are not particularly high, the nonlinear fitting extension based on the least squares method may be a suitable choice; if the amount of data is large and you want to find the global optimal solution through the optimization algorithm, then the genetic algorithm or particle swarm optimization algorithm may be more suitable.

[0099] (6) Taking the nonlinear fitting extension based on the least squares method (such as the Levenberg-Marquardt algorithm) as an example, the measured capacitance value data, L value and NF value collected and preprocessed are used as input data and substituted into the calculation process of the algorithm. In the specific operation, professional mathematical software (such as Matlab, relevant scientific computing libraries in Python, etc.) can be used to implement it. In Matlab, you can use the built-in fitting function (such as the nlinfit function, etc.), set the fitting model in the form of the functional relationship C(L,NF)=A*(NF*B+C) / L, and pass the measured data as parameters. The parameter values ​​of A, B, C, etc. in the functional relationship are obtained by calculation, so as to determine the specific functional relationship expression. In Python, the optimize module in the SciPy library (such as the curve_fit function, etc.) can be used to implement similar functions. The measured capacitance value data, L value and NF value are also used as inputs, and the fitting model is set in the form of the functional relationship, so as to obtain the parameter values ​​and determine the functional relationship expression.

[0100] (7) After obtaining the preliminary functional relationship, it is necessary to evaluate its fitting effect. Commonly used evaluation indicators include mean square error (MSE), determination coefficient (R 2 ) etc. The mean square error (MSE) measures the accuracy of the fit by calculating the average of the sum of squares of the errors between the fitting function and the measured data points. The smaller the MSE value, the better the fit effect. 2 ) is an indicator to measure the degree to which the fitting function can explain the variation of the measured data, R 2 The closer the value is to 1, the better the fitting effect is, and the fitting function can better explain the variation law of the measured data. By calculating these evaluation indicators, we can intuitively understand the degree of fit of the currently determined functional relationship to the measured data.

[0101] -(8) If the evaluation results show that the fitting effect is not ideal (such as a large MSE value, R 2 The value is far below 1, etc.), then the functional relationship needs to be optimized. There are many ways to optimize, such as adjusting the assumed form of the functional relationship, adding or reducing some items in the original assumed functional relationship, such as adjusting the coefficients B or C in the original assumed functional relationship, or adding a new constant term to the functional relationship; or reselecting the fitting method, such as changing from the nonlinear fitting expansion based on the least squares method to the genetic algorithm. Then perform the fitting calculation and evaluation again until a functional relationship with a better fitting effect is obtained, which can better explain the variation pattern of the measured data.

[0102] To this end, determining the functional relationship between the calibration capacitance value and L and NF based on the first measured capacitance value data, the second measured capacitance value data, the third measured capacitance value data, and the fourth measured capacitance value data has the following technical benefits:

[0103] (1) By determining the functional relationship between the capacitance value and the MOMCAP finger length (L) and the number of fingers (NF), these two key parameters that have an important impact on the capacitor performance can be comprehensively considered. Different combinations of finger length and number of fingers will cause the capacitance value to change, and this functional relationship can accurately capture this change pattern. For example, during chip design or manufacturing, when it is necessary to know the capacitance value under a certain L and NF value, there is no need to perform actual measurements again. Simply substitute the corresponding L and NF values ​​into the determined functional relationship to accurately predict the capacitance value, which is very helpful for quickly evaluating the capacitor performance under different design schemes.

[0104] (2) During the design phase of MOMCAP, understanding the functional relationship between capacitance and L and NF can help designers optimize the capacitor structure design. They can achieve the design goal by adjusting parameters such as finger length and number of fingers according to the target capacitance and other performance requirements. For example, if the capacitance needs to be increased, it can be analyzed based on the functional relationship to determine whether increasing the finger length or the number of fingers is more effective, or to determine the appropriate adjustment range of the two, thereby achieving more efficient design optimization, improving capacitor performance and meeting the needs of specific application scenarios.

[0105] (3) For chip manufacturing processes, this functional relationship can help process personnel analyze the impact of process deviation on capacitance. When the capacitance of the calibration structure actually manufactured does not match the theoretical expectation, by substituting the measured L and NF values ​​into the functional relationship, it can be determined whether the L and NF changes caused by process deviations affect the capacitance value, or whether it is caused by other factors. This enables process personnel to make targeted adjustments and improvements to the manufacturing process, thereby improving the consistency of chip manufacturing quality and capacitance performance.

[0106] (4) Once the functional relationship between the capacitance value and L and NF is determined, when evaluating other MOMCAP capacitors with similar structures in the future, there is no need to conduct comprehensive actual measurements on the capacitors with different parameter combinations. It is only necessary to know the corresponding L and NF values ​​and use the functional relationship to calculate the capacitance value, which greatly reduces the testing workload. Especially in large-scale production or verification of multiple different parameter designs, this method can save a lot of testing time, equipment resources and labor costs, and improve work efficiency.

[0107] (5) The determined functional relationship provides an important data basis for the modeling of MOMCAP capacitors. It establishes a clear connection between the capacitance value and the two key structural parameters L and NF, so that when establishing the capacitor performance model, it can more accurately reflect the actual situation of the capacitance value changing with L and NF. Compared with modeling based on limited measured data points, the functional relationship can simulate and predict the capacitor performance within a wider parameter range, thereby improving the accuracy of MOMCAP capacitor modeling and laying a solid foundation for subsequent model-based analysis, design optimization and other work.

[0108] (6) This functional relationship determined based on measured data has strong versatility and adaptability. Whether in different chip design projects, as long as MOMCAP capacitors with similar structures are involved, or in the same project facing different application scenarios and performance requirements, this functional relationship can play a role. It can accurately calculate the corresponding capacitance value based on the specific L and NF values, providing a unified and effective tool for capacitor performance evaluation and design adjustment in different situations, enhancing the applicability of MOMCAP capacitors in various application scenarios.

[0109] Optionally, the acquiring of a test object comprising a plurality of groups of calibration structures associated with the same MOMCAP standard test structure includes: calculating capacitance values ​​of calibration structures of other sizes in the plurality of groups of calibration structures based on a functional relationship between the calibration capacitance value and L and NF.

[0110] When calculating the capacitance values ​​of calibration structures of other sizes in the plurality of groups of calibration structures based on the functional relationship between the calibration capacitance value and L and NF, the following process may be included:

[0111] (1) It is necessary to clarify the specific parameter information of other size calibration structures for calculating the capacitance value. For MOMCAP capacitors, the focus is on the two parameters closely related to the capacitance value: the finger length (L) and the number of fingers (NF). These parameter information can be obtained through the chip design file, which records the design dimensions of each calibration structure in detail, including the specific value of the finger length (usually in microns or nanometers) and the set value of the number of fingers.

[0112] The obtained L and NF values ​​of calibration structures of other sizes are organized into a data table, where each row corresponds to a calibration structure, and records its structure number, L value, NF value and other information. This facilitates the subsequent calculation of the capacitance value based on the functional relationship, and can clearly record and trace the relevant parameters and calculation results of each calibration structure.

[0113] (2) Select the appropriate calculation tool based on the complexity of the functional relationship between the determined calibration capacitance value and L and NF. If the functional relationship is relatively simple, such as a relatively regular polynomial function or a simple fractional function, common spreadsheet software (such as Excel) can be used for calculation. In Excel, the capacitance value can be automatically calculated by entering the function expression in a cell and substituting the corresponding L value and NF value cells as variables.

[0114] For more complex functional relationships, such as those involving nonlinear terms, exponential functions, logarithmic functions, etc., it is recommended to use professional mathematical computing software (such as Matlab, related scientific computing libraries in Python, etc.). In Matlab, you can write a script program that uses the obtained L value and NF value as input data, and program the calculation according to the expression of the functional relationship to obtain the capacitance value of each calibration structure. In Python, the calculation of complex functions can be easily realized using libraries such as SciPy and NumPy. For example, by defining a function and passing in the L value and NF value parameters, the capacitance value can be accurately calculated.

[0115] (3) Ensure that the L value and NF value of each other size calibration structure are accurately substituted into the functional relationship between the calibration capacitance value and L and NF for calculation. For example, if the functional relationship is $C(L,NF)=A*(NF*B+C) / L$ (this is just an example), when calculating the capacitance value of a calibration structure, first obtain the L value and NF value of the structure, and then substitute them into the L and NF positions in the functional relationship respectively, and calculate according to the established operation rules (calculate the contents in brackets first, then perform multiplication and division operations, etc.) to obtain the capacitance value of the calibration structure. During the calculation process, pay attention to the matching of data types and the correctness of the operation order to avoid calculation errors.

[0116] (4) Record the capacitance value of each other size calibration structure calculated by the functional relationship into the previously sorted data table, and add a new column to record the capacitance value results. In this way, the relevant parameters (L value, NF value) of each calibration structure and the calculated capacitance value can be fully saved, which is convenient for subsequent analysis and comparison of the calculation results and comparison with the actual measured values ​​(if any).

[0117] Based on some basic theories and empirical formulas of MOMCAP capacitors, theoretical estimates are made for the capacitance values ​​of other size calibration structures. Although these theoretical estimates may not be as accurate as the results calculated based on the functional relationship determined by the measured data, they can be used as a preliminary reference. Compare the calculated results with the theoretical estimated values. If the difference between the two is not much (within the acceptable error range, determined according to industry standards or specific project requirements), it means that the calculated results have a certain rationality.

[0118] For some other size calibration structures, sampling can be performed to actually measure their capacitance values. Use a professional capacitance tester (such as an LCR tester) to test the capacitance of the sampled calibration structure according to the standard test process. Compare the actual measured value with the result calculated by the functional relationship. If the two match (also within the acceptable error range), the accuracy of the calculation result is further verified. If it is found that there is a large difference between the calculated result and the actual measured value, it is necessary to check whether the functional relationship is correct, whether the substituted parameter values ​​are accurate, and whether there are errors in the calculation process, and make corrections and recalculations in a timely manner.

[0119] Figure 2 This is the MOMCAP normal and calibration structure size information in a specific scenario of this application. Figure 2 As shown, assuming that the L range is 1-30um and the Nf range is 6-60. Based on the prior art, the calibration structure needs to correspond to the normal structure one by one, that is, 24 calibration structures are also required. According to the present application scheme, only 4 are required: the calibration structure with the maximum L and the maximum NF, and the calibration structure with the minimum L and the minimum NF.

[0120] Figure 3 This is a flow chart of a capacitance calibration method according to an embodiment of the present application. Figure 3 As shown, it includes:

[0121] Obtain the capacitance value of the MOMCAP standard test structure and the capacitance values ​​of several groups of calibration structures corresponding thereto, wherein the capacitance values ​​of the several groups of calibration structures are calculated based on any method of the embodiments of the present application;

[0122] Based on the difference between the capacitance value of the MOMCAP standard test structure and the capacitance values ​​of several groups of calibration structures corresponding thereto, the calibrated capacitance value is calculated.

[0123] Figure 4 This is a flow chart of a MOMCAP capacitor modeling method according to an embodiment of the present application. Figure 4 As shown, it includes:

[0124] Obtain a calibrated capacitance value of the MOMCAP, wherein the calibrated capacitance value of the MOMCAP is calculated based on the method described in any one of the present application;

[0125] The MOMCAP capacitance model is obtained by performing MOMCAP capacitance modeling based on the calibrated capacitance value of the MOMCAP.

[0126] Figure 5 FIG. 1 is a flow chart of a circuit simulation method according to an embodiment of the present application. Figure 5 As shown, it includes:

[0127] Performing MOMCAP capacitance modeling based on the calibrated capacitance value of the MOMCAP to obtain a MOMCAP capacitance model, wherein the calibrated capacitance value of the MOMCAP is calculated based on the method described in the embodiment of the present application;

[0128] Based on the MOMCAP capacitor model, circuit simulation is performed.

[0129] An embodiment of the present application also provides a circuit simulation system, which includes: a simulation host, wherein the simulation host is used to perform MOMCAP capacitance modeling based on the calibrated capacitance value of the MOMCAP to obtain a MOMCAP capacitance model, and to perform circuit simulation based on the MOMCAP capacitance model, wherein the calibrated capacitance value of the MOMCAP is calculated based on the method described in the embodiment of the present application.

[0130] In the above embodiment, L represents the length of the MOMCAP finger, and NF represents the number of MOMCAP fingers.

[0131] In a specific scenario, the functional relationship is, for example: C(L, NF)=A*(NF*B+C) / L, where A, B, and C are all fitting parameters, and these fitting parameters are determined based on the first measured capacitance value data, the second measured capacitance value data, the third measured capacitance value data, and the fourth measured capacitance value data.

[0132] The capacitance values ​​of calibration structures of other sizes in the plurality of groups of calibration structures can be calculated based on the functional relationship C(L, NF).

[0133] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0134] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A method for determining the capacitance value of a calibration test structure, characterized in that: include: Obtaining a test object including a plurality of sets of calibration structures associated with the same MOMCAP standard test structure; Selecting a number of representative calibration structures from the plurality of calibration structures according to a specific parameter combination; Performing capacitance value tests on each selected group of calibration structures to obtain corresponding measured capacitance value data; Based on these measured capacitance value data, analyze and determine the functional relationship between the calibration capacitance value and the selected parameters; By using the functional relationship, the capacitance values ​​of other calibration structures with different parameter combinations are calculated.

2. The method for determining the capacitance value of a calibration test structure according to claim 1, characterized in that: The obtaining of a test object including multiple groups of calibration structures, which are associated with the same MOMCAP standard test structure, includes: obtaining a test object, which includes at least several groups of calibration structures, which are associated with the same MOMCAP normal test structure.

3. The method for determining the capacitance value of a calibration test structure according to claim 2, characterized in that: The acquiring of a test object comprising a plurality of groups of calibration structures, wherein the calibration structures are associated with the same MOMCAP standard test structure, comprises: selecting the following first group of calibration structures, second group of calibration structures, third group of calibration structures, and fourth group of calibration structures from the plurality of groups of calibration structures, wherein the first group of calibration structures is a combination of calibration structures having a maximum L and a maximum NF, the second group of calibration structures is a combination of calibration structures having a minimum L and a minimum NF, the third group of calibration structures is a combination of calibration structures having a maximum L and a minimum NF, and the fourth group of calibration structures is a combination of calibration structures having a minimum L and a maximum NF.

4. The method for determining the capacitance value of a calibration test structure according to claim 3, characterized in that: The obtaining of a test object comprising multiple groups of calibration structures, which are associated with the same MOMCAP standard test structure, includes: performing capacitance value tests on the first group of calibration structures, the second group of calibration structures, the third group of calibration structures, and the fourth group of calibration structures, respectively, to obtain first measured capacitance value data, second measured capacitance value data, third measured capacitance value data, and fourth measured capacitance value data.

5. The method for determining the capacitance value of a calibration test structure according to claim 4, characterized in that: The acquiring of a test object comprising a plurality of calibration structures, wherein the calibration structures are associated with the same MOMCAP standard test structure, includes: determining a functional relationship between the calibration capacitance value and L and NF based on the first measured capacitance value data, the second measured capacitance value data, the third measured capacitance value data, and the fourth measured capacitance value data.

6. The method for determining the capacitance value of a calibration test structure according to claim 5, characterized in that: The obtaining of a test object comprising a plurality of groups of calibration structures, wherein the calibration structures are associated with the same MOMCAP standard test structure, includes: calculating the capacitance values ​​of calibration structures of other sizes in the plurality of groups of calibration structures based on a functional relationship between the calibration capacitance value and L and NF.

7. A capacitance calibration method, characterized in that: include: Obtain the capacitance value of the MOMCAP standard test structure and the capacitance values ​​of several groups of calibration structures corresponding thereto, wherein the capacitance values ​​of the several groups of calibration structures are calculated based on any one of the methods of claims 1-6; Based on the difference between the capacitance value of the MOMCAP standard test structure and the capacitance values ​​of several groups of calibration structures corresponding thereto, the calibrated capacitance value is calculated.

8. A MOMCAP capacitor modeling method, characterized in that: include: Obtaining a calibrated capacitance value of the MOMCAP, wherein the calibrated capacitance value of the MOMCAP is calculated based on the method of claim 7; The MOMCAP capacitance model is obtained by performing MOMCAP capacitance modeling based on the calibrated capacitance value of the MOMCAP.

9. A circuit simulation method, characterized in that: include: Performing MOMCAP capacitance modeling based on the calibrated capacitance value of the MOMCAP to obtain a MOMCAP capacitance model, wherein the calibrated capacitance value of the MOMCAP is calculated based on the method described in claim 7; Based on the MOMCAP capacitor model, circuit simulation is performed.

10. A circuit simulation system, characterized in that: include: A simulation host, wherein the simulation host is used to perform MOMCAP capacitance modeling based on the calibrated capacitance value of the MOMCAP to obtain a MOMCAP capacitance model, and to perform circuit simulation based on the MOMCAP capacitance model, wherein the calibrated capacitance value of the MOMCAP is calculated based on the method described in claim 7.

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