Wafer pattern step height measuring method, device, equipment and medium

Abstract

The invention discloses a wafer pattern step height measurement method, device and equipment and a medium. The method comprises the following steps: acquiring a wafer pattern step height measurement curve and a motor movement distance measurement curve; respectively sampling the wafer pattern step height measurement curve and the motor movement distance measurement curve to obtain a preset sampling number of step height measurement values and a preset sampling number of movement distance measurement values; linear fitting is carried out based on the step height measurement value and the moving distance measurement value obtained through sampling, and an intercept fitting coefficient and a slope fitting coefficient are determined; and determining a target step height measurement value based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value. Through the technical scheme of the embodiment of the invention, accurate measurement of the wafer pattern step height is realized, the accuracy and repeatability of image step height measurement are improved, wafers with poor patterns can be quickly and accurately detected, and the yield of chip production is greatly increased.

Description

Technical Field

[0001] The present invention relates to the field of computer technology, and in particular to a method, device, equipment and medium for measuring the step height of a wafer pattern. Background Art

[0002] The wafer pattern step height is a very important parameter in the microelectronics manufacturing process, which has a significant impact on the performance of components such as transistors. With the continuous development of semiconductor technology, the measurement accuracy and stability of wafer pattern step height are increasingly required.

[0003] At present, the existing wafer pattern step height measurement method is usually to measure by directly contacting the pattern surface with a probe. However, since the existing method needs to directly contact the pattern surface, it will be disturbed by circuit noise and external environmental sound vibration when the motor vibrates, which will reduce the accuracy and repeatability of the image step height measurement, which is not conducive to the rapid and accurate detection of bad pattern wafers and reduces the yield rate of chip production. Summary of the invention

[0004] The present invention provides a wafer pattern step height measurement method, device, equipment and medium to achieve accurate measurement of wafer pattern step height, improve the accuracy and repeatability of image step height measurement, facilitate rapid and accurate detection of defective pattern wafers, and greatly increase the yield rate of chip production.

[0005] In a first aspect, an embodiment of the present invention provides a method for measuring a wafer pattern step height, comprising:

[0006] Obtain wafer pattern step height measurement curve and motor moving distance measurement curve;

[0007] The wafer pattern step height measurement curve and the motor moving distance measurement curve are sampled respectively to obtain a preset number of sampled step height measurement values ​​and a preset number of sampled moving distance measurement values;

[0008] Performing straight line fitting based on the step height measurement values ​​of the preset number of samplings and the moving distance measurement values ​​of the preset number of samplings, and determining the intercept fitting coefficient and the slope fitting coefficient in the fitted straight line;

[0009] Based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value, the step height measurement value is filtered to determine a target step height measurement value.

[0010] In a second aspect, an embodiment of the present invention further provides a wafer pattern step height measurement device, comprising:

[0011] A measurement curve acquisition module is used to obtain a wafer pattern step height measurement curve and a motor moving distance measurement curve;

[0012] A sampling module, used to sample the wafer pattern step height measurement curve and the motor moving distance measurement curve respectively, to obtain a preset number of sampled step height measurement values ​​and a preset number of sampled moving distance measurement values;

[0013] A fitting module, used to perform straight line fitting based on the step height measurement values ​​of the preset sampling number and the moving distance measurement values ​​of the preset sampling number, and determine the intercept fitting coefficient and the slope fitting coefficient in the fitted straight line;

[0014] The measurement module is used to filter the step height measurement value based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value to determine the target step height measurement value.

[0015] In a third aspect, an embodiment of the present invention further provides an electronic device, characterized in that the electronic device comprises: at least one processor; and

[0016] a memory communicatively connected to the at least one processor; wherein,

[0017] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the wafer graphic step height measurement method provided by any embodiment of the present invention.

[0018] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to execute the wafer graphic step height measurement method provided by any embodiment of the present invention when executing.

[0019] The technical solution of the embodiment of the present invention can convert continuous measurement data into discrete measurement values ​​by acquiring the wafer graphic step height measurement curve and the motor moving distance measurement curve, and sampling the wafer graphic step height measurement curve and the motor moving distance measurement curve respectively, obtaining the step height measurement values ​​of the preset sampling number and the moving distance measurement values ​​of the preset sampling number, so as to facilitate subsequent data processing and analysis. A straight line fitting is performed based on the step height measurement values ​​of the preset sampling number and the moving distance measurement values ​​of the preset sampling number, and the intercept fitting coefficient and the slope fitting coefficient in the fitted straight line are determined to reflect the linear relationship between the wafer graphic step height and the motor moving distance. Based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value, the step height measurement value is filtered to determine the target step height measurement value, which can eliminate abnormal values ​​and noise in the measurement data and improve the accuracy and stability of the data. By sampling the acquired measurement curve, obtaining the fitting straight line, and then denoising the actual measurement value, accurate measurement and analysis of the wafer graphic step height can be achieved, which is conducive to the rapid and accurate detection of defective graphic wafers and greatly increases the yield rate of chip production.

[0020] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 is a flow chart of a wafer pattern step height measurement method provided according to Embodiment 1 of the present invention;

[0023] Figure 2 This is a structural diagram of a wafer step pattern measurement platform according to Embodiment 1 of the present invention;

[0024] Figure 3 is a schematic diagram of a change in capacitor position according to Embodiment 1 of the present invention;

[0025] Figure 4 is a schematic diagram of an actual vibration noise involved in Embodiment 1 of the present invention;

[0026] Figure 5is a flow chart of a wafer pattern step height measurement method provided according to Embodiment 2 of the present invention;

[0027] Figure 6 is a structural schematic diagram of a wafer pattern step height measurement device provided according to a third embodiment of the present invention;

[0028] Figure 7 It is a structural schematic diagram of an electronic device for implementing the wafer pattern step height measurement method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "target", "current", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0031] Embodiment 1

[0032] Figure 1 A flowchart of a wafer pattern step height measurement method is provided for the first embodiment of the present invention. This embodiment is applicable to the case of measuring the wafer pattern step height. Figure 1 As shown, the method can be performed by a wafer pattern step height measurement device, which can be implemented in the form of hardware and / or software, and can be configured in an electronic device. Figure 1 As shown, the method specifically comprises the following steps:

[0033] S110, obtaining a wafer pattern step height measurement curve and a motor moving distance measurement curve.

[0034] Among them, the wafer pattern may refer to a graphic structure with a specific shape and size formed on the wafer through processes such as photolithography and etching. The wafer may refer to a silicon wafer used to make silicon semiconductor integrated circuits. The wafer pattern step height may refer to the height difference between different graphic structures on the wafer compared to the wafer plane. The wafer pattern step height measurement curve may refer to a curve obtained by measuring the step heights at different positions on the wafer. The motor movement distance measurement curve may refer to a curve formed by the movement distance that changes with time when the motor drives a measuring device (such as a scanning probe microscope, etc.).

[0035] Specifically, the wafer step pattern measurement platform is used to measure the wafer pattern step height, and the measurement data is recorded to form a wafer pattern step height measurement curve. At the same time, the moving distance of the motor during the measurement process is recorded to form a motor moving distance measurement curve. By obtaining direct measurement data of the wafer pattern step height and accurate records of the motor moving distance, a reliable basis is provided for subsequent data processing and analysis.

[0036] S120 , sampling the wafer pattern step height measurement curve and the motor moving distance measurement curve respectively to obtain a preset number of sampled step height measurement values ​​and a preset number of sampled moving distance measurement values.

[0037] The preset sampling number may refer to the number of sampling points set in advance. The step height measurement value may refer to the specific value obtained by measuring the step height of the wafer pattern. The moving distance measurement value may refer to the specific value obtained by measuring the moving distance of the motor.

[0038] Specifically, according to a preset number of samples (such as 10 points per millimeter), the wafer pattern step height measurement curve and the motor moving distance measurement curve are sampled respectively to obtain the preset number of step height measurement values ​​and the preset number of moving distance measurement values. Through sampling, continuous measurement data can be converted into discrete measurement values, which is convenient for subsequent data processing and analysis.

[0039] Exemplarily, S120 may include: smoothing the wafer graphic step height measurement curve and the motor movement distance measurement curve to obtain a preprocessed wafer graphic step height measurement curve and a preprocessed motor movement distance measurement curve; performing curve characteristic analysis based on the preprocessed wafer graphic step height measurement curve and the preprocessed motor movement distance measurement curve to determine the sampling frequency; sampling the preprocessed wafer graphic step height measurement curve and the preprocessed motor movement distance measurement curve based on the sampling frequency, respectively, to obtain a preset number of sampled step height measurement values ​​and a preset number of sampled movement distance measurement values.

[0040] Specifically, mathematical methods (such as moving average method, Gaussian filtering, etc.) can be used to smooth the wafer graphic step height measurement curve and the motor moving distance measurement curve. Select appropriate smoothing parameters to ensure that the key features of the curve are retained while removing noise. Perform spectrum analysis, autocorrelation analysis, etc. on the preprocessed wafer graphic step height measurement curve and the preprocessed motor moving distance measurement curve to understand the frequency components and periodic characteristics of the curve, and determine the appropriate sampling frequency based on the analysis results to ensure that the key information of the curve can be captured during the sampling process. According to the determined sampling frequency, the preprocessed wafer graphic step height measurement curve and the preprocessed motor moving distance measurement curve are sampled at equal intervals or randomly. Record the step height measurement value and moving distance measurement value of each sampling point. Ensure that the number of samples reaches the preset value to meet the needs of subsequent analysis and processing.

[0041] S130 , performing straight line fitting based on a preset number of step height measurement values ​​and a preset number of moving distance measurement values, and determining an intercept fitting coefficient and a slope fitting coefficient in the fitted straight line.

[0042] The intercept fitting coefficient may refer to the intercept of the linear relationship between the wafer pattern step height and the motor moving distance. The slope fitting coefficient may refer to the slope of the linear relationship between the wafer pattern step height and the motor moving distance.

[0043] Specifically, a straight line fitting algorithm can be used to perform straight line fitting on the step height measurement values ​​of a preset number of samples and the moving distance measurement values ​​of a preset number of samples to obtain the intercept fitting coefficient and the slope fitting coefficient in the fitting line. The random error and noise in the measurement data can be eliminated by straight line fitting, and the accuracy and reliability of the data can be improved. At the same time, the intercept fitting coefficient and the slope fitting coefficient can reflect the linear relationship between the wafer pattern step height and the motor moving distance.

[0044] Exemplarily, S130 may include: determining the intercept fitting coefficient corresponding to the fitting straight line based on the intercept fitting formula, the step height measurement values ​​of a preset number of samplings, and the moving distance measurement values ​​of a preset number of samplings; determining the slope fitting coefficient corresponding to the fitting straight line based on the slope fitting formula, the step height measurement values ​​of a preset number of samplings, and the moving distance measurement values ​​of a preset number of samplings, wherein the intercept fitting formula and the slope fitting formula are determined based on a preset fitting algorithm.

[0045] The intercept fitting formula may refer to a formula for calculating the intercept fitting coefficient determined according to a preset fitting algorithm. The slope fitting formula may refer to a formula for calculating the slope fitting coefficient determined according to a preset fitting algorithm. The preset fitting algorithm may refer to a fitting algorithm pre-selected before performing straight line fitting. For example, the preset fitting algorithm may be the least squares method.

[0046] Specifically, the step height measurement values ​​and the moving distance measurement values ​​of the preset sampling number are substituted into the intercept fitting formula, and the intercept fitting coefficient is calculated. The intercept fitting coefficient reflects the theoretical value of the wafer graphic step height when the motor moving distance is 0 (theoretically), which provides an important reference for analyzing the process and predicting future trends. The step height measurement values ​​and the moving distance measurement values ​​of the preset sampling number are substituted into the slope fitting formula, and the slope fitting coefficient is calculated. The slope fitting coefficient can reflect the strength of the linear relationship between the motor moving distance and the wafer graphic step height, and provides a direct basis for analyzing the impact of changes in process parameters on the step height.

[0047] Exemplarily, the intercept fitting formula is:

[0048]

[0049] Among them, C1 is the intercept fitting coefficient, y i is the measured value of step height, x i is the moving distance measurement value, n is the preset sampling number;

[0050] The slope fitting formula is:

[0051]

[0052] Among them, C2 is the slope fitting coefficient, y i is the measured value of step height, x i is the measured value of the moving distance.

[0053] S140, based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value, filtering the step height measurement value to determine the target step height measurement value.

[0054] The target step height measurement value may refer to a measurement value representing the step height of a specific graphic structure on the wafer that is not affected by noise vibration during the measurement of the step height of the wafer graphic.

[0055] Specifically, the theoretical value of each step height measurement value is calculated based on the intercept fitting coefficient, the slope fitting coefficient, and the moving distance measurement value corresponding to each step height measurement value. The actual value of each step height measurement value is compared with the theoretical value, and the step height measurement value is filtered according to a preset filtering rule (such as threshold filtering), and the step height measurement value that meets the filtering rule is retained as the target step height measurement value. Through filtering, outliers and noise in the measurement data can be further eliminated, and the accuracy and stability of the data can be improved. At the same time, the target step height measurement value can more truly reflect the actual situation of the wafer graphic step height.

[0056] The technical solution of the embodiment of the present invention, by acquiring the wafer graphic step height measurement curve and the motor moving distance measurement curve, and sampling the wafer graphic step height measurement curve and the motor moving distance measurement curve respectively, obtaining the step height measurement value of the preset sampling number and the moving distance measurement value of the preset sampling number, can convert continuous measurement data into discrete measurement values, which is convenient for subsequent data processing and analysis. Based on the step height measurement value of the preset sampling number and the moving distance measurement value of the preset sampling number, a straight line fitting is performed to determine the intercept fitting coefficient and the slope fitting coefficient in the fitted straight line, reflecting the linear relationship between the wafer graphic step height and the motor moving distance. Based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value, the step height measurement value is filtered to determine the target step height measurement value, which can eliminate abnormal values ​​and noise in the measurement data and improve the accuracy and stability of the data. By sampling the acquired measurement curve, obtaining the fitting straight line, and then denoising the actual measurement value, the accurate measurement and analysis of the wafer graphic step height can be achieved, which is conducive to the rapid and accurate detection of bad graphic wafers, and greatly increases the yield rate of chip production.

[0057] Exemplarily, the structure of the wafer step pattern measurement platform is as follows: Figure 2As shown, the detection probe is based on the lever principle, and the measurement platform is composed of a probe detection module, a chuck table (stage), a one-dimensional motion module and a computer module. The probe detection module consists of an L-shaped probe, a two-stage capacitor plate, a baffle paddle, and an electromagnetic coil. The one-dimensional motion module can be an ordinary linear motor, and the chuck table is fixed on the linear motor. The linear motor drives the chuck table to move back and forth along the X-axis direction. The chuck table is used to place the wafer. The chuck table and the linear motor are relatively parallel through the left and right leveling screws. The computer module calculates, analyzes, stores, and displays the collected data. When the probe scans the graphic steps at a constant speed, the probe will change up and down according to the height of the steps. At the same time, the baffle paddle at the other end of the fulcrum also moves up and down between the two capacitor plates. The baffle paddle moves up and down between the two capacitor plates, and also forms two upper and lower capacitance values. After power is turned on, the two capacitors will form a potential difference. The change of the capacitor position over time can be shown as follows Figure 3 As shown. The potential difference can be converted into the actual step height analog value through the expression of the capacitance difference and the blade movement distance, and then the analog value is converted into a digital value through a 24-bit analog-to-digital chip to represent the wafer graphic step height measurement value. During the probe scanning of the wafer graphic steps, the probe remains stationary after contacting the measured plane, and the measured sample is placed on the micro-motion platform. The micro-motion platform moves horizontally along the X-axis direction driven by the motor, and the measured sample is also scanned by the probe at a uniform speed. In this process, the micro-motion platform will inevitably vibrate slightly due to the influence of the motor. The vibration of the micro-motion platform movement and the vibration noise of the resonance of the capacitor pick caused by the external sound of the environment will affect the measurement results. The actual noise description when scanning the wafer graphics can be as follows Figure 4 shown.

[0058] Embodiment 2

[0059] Figure 5 This is a flow chart of a wafer pattern step height measurement method provided in Embodiment 2 of the present invention. Based on the above embodiments, this embodiment optimizes the step of "filtering the step height measurement value based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value to determine the target step height measurement value". The explanations of the terms that are the same or corresponding to the above embodiments are not repeated here.

[0060] See also Figure 5 Another wafer pattern step height measurement method provided in this embodiment specifically includes the following steps:

[0061] S210, obtaining a wafer pattern step height measurement curve and a motor moving distance measurement curve.

[0062] S220 , sampling the wafer pattern step height measurement curve and the motor moving distance measurement curve respectively to obtain a preset number of sampled step height measurement values ​​and a preset number of sampled moving distance measurement values.

[0063] S230 , performing straight line fitting based on a preset number of step height measurement values ​​and a preset number of moving distance measurement values, and determining an intercept fitting coefficient and a slope fitting coefficient in the fitted straight line.

[0064] S240: Determine a step height fitting value based on the intercept fitting coefficient, the slope fitting coefficient and the moving distance measurement value.

[0065] The step height fitting value may refer to a predicted value of the step height, which reflects the changing trend of the step height with the moving distance under ideal conditions (ie, without considering interference factors such as noise and vibration).

[0066] Specifically, if the intercept fitting coefficient and the slope fitting coefficient are known, as well as the moving distance measurement value corresponding to each step height measurement value, the equation corresponding to the fitting straight line can be directly obtained. According to the fitting straight line equation, each moving distance measurement value is substituted into the equation to calculate the corresponding step height fitting value, which can be used as a theoretical reference value for the step height for subsequent comparison and analysis with the actual measurement value.

[0067] Exemplarily, the step height fitting value may be determined according to the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value, and the moving distance measurement value by the following formula:

[0068] Y i =C1+C2x i

[0069] Among them, Y i is the fitted value of the step height.

[0070] S250: Determine a noise vibration deviation based on the step height fitting value and the step height measurement value.

[0071] The noise-vibration deviation may refer to the step height measurement error caused by random noise, vibration interference and other non-ideal factors introduced during the measurement process.

[0072] Specifically, the step height fitting value is subtracted from the corresponding step height measurement value, and the difference between the two is calculated, namely the noise vibration deviation, which reflects the measurement error caused by factors such as noise and vibration in the actual measurement process.

[0073] Exemplarily, S250 may include: determining the difference between the step height fitting value and the step height measurement value corresponding to each sampling point as the noise vibration deviation corresponding to each sampling point, and obtaining the noise vibration deviation of a preset number of samples.

[0074] Specifically, the difference between the step height fitting value and the step height measurement value corresponding to each sampling point is calculated, and the deviation between the step height fitting value corresponding to each sampling point and the step height measurement value corresponding to each sampling point, that is, the noise vibration deviation, is determined to obtain the noise vibration deviation of the preset number of samples. By calculating the noise vibration deviation, the difference between the actual measurement value and the theoretical reference value can be quantified, providing a basis for subsequent data processing and analysis.

[0075] Exemplarily, the noise vibration deviation may be determined according to the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value, and the moving distance measurement value by the following formula:

[0076] Z i =C1+C2x i -y i

[0077] Among them, Z i is the noise vibration deviation.

[0078] S260: Process the step height measurement value based on the noise vibration deviation to determine the target step height measurement value.

[0079] Specifically, the noise and vibration deviations are processed according to preset filtering rules, the noise and vibration deviations corresponding to each step height measurement value are eliminated, and the target step height measurement value is determined based on the filtered step height measurement value, which can eliminate the noise and vibration errors in the measurement data and improve the accuracy and stability of the data.

[0080] Exemplarily, S260 may include: determining a step height measurement mean based on a preset number of sampled step height measurement values; determining a noise vibration deviation mean based on a preset number of sampled noise vibration deviations; and subtracting the step height measurement mean from the noise vibration deviation mean to determine a target step height measurement value.

[0081] Specifically, the step height measurement values ​​of the preset number of samples are arithmetic averaged to obtain the step height measurement mean; the noise and vibration deviations of the preset number of samples are arithmetic averaged to obtain the noise and vibration deviation mean; the step height measurement mean is subtracted from the noise and vibration deviation mean to obtain the target step height measurement value. Through the subtraction operation, the average influence of noise and vibration on the step height measurement value can be removed to obtain a more accurate target step height measurement value.

[0082] For example, the target step height measurement value may be determined according to the noise vibration deviation and the step height measurement value by the following formula:

[0083]

[0084] Where Step is the measured value of the target step height.

[0085] The technical solution of the embodiment of the present invention can obtain a fitting straight line that can reflect the linear relationship between the step height and the moving distance based on the intercept fitting coefficient, the slope fitting coefficient and the moving distance measurement value, and determine the step height fitting value. Based on the step height fitting value and the step height measurement value, the noise vibration deviation is determined, thereby quantifying the measurement deviation caused by the noise vibration. Based on the noise vibration deviation, the step height measurement value is processed to determine the target step height measurement value, thereby eliminating the noise and vibration errors in the measurement data and improving the accuracy and stability of the data. By calculating the step height fitting value through the fitting straight line and the moving distance measurement value, and then calculating the noise vibration deviation, the measurement deviation caused by the noise vibration can be quantified, and the step height measurement value is further filtered to determine a more accurate and stable target step height measurement value.

[0086] Embodiment 3

[0087] Figure 6 This is a schematic diagram of the structure of a wafer pattern step height measurement device provided by the third embodiment of the present invention. Figure 6 As shown, the device includes: a measurement curve acquisition module 310 , a sampling module 320 , a fitting module 330 and a measurement module 340 .

[0088] Among them, the measurement curve acquisition module 310 is used to obtain the wafer pattern step height measurement curve and the motor moving distance measurement curve;

[0089] A sampling module 320 is used to sample the wafer pattern step height measurement curve and the motor moving distance measurement curve respectively to obtain a preset number of sampled step height measurement values ​​and a preset number of sampled moving distance measurement values;

[0090] A fitting module 330, configured to perform straight line fitting based on the step height measurement values ​​of the preset number of samplings and the moving distance measurement values ​​of the preset number of samplings, and determine an intercept fitting coefficient and a slope fitting coefficient in the fitted straight line;

[0091] The measurement module 340 is used to filter the step height measurement value based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value to determine a target step height measurement value.

[0092] The technical solution of this embodiment, by acquiring the wafer graphic step height measurement curve and the motor moving distance measurement curve, and sampling the wafer graphic step height measurement curve and the motor moving distance measurement curve respectively, obtains the step height measurement values ​​of the preset sampling number and the moving distance measurement values ​​of the preset sampling number, and can convert continuous measurement data into discrete measurement values, which is convenient for subsequent data processing and analysis. Based on the step height measurement values ​​of the preset sampling number and the moving distance measurement values ​​of the preset sampling number, a straight line fitting is performed to determine the intercept fitting coefficient and the slope fitting coefficient in the fitted straight line, reflecting the linear relationship between the wafer graphic step height and the motor moving distance. Based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value, the step height measurement value is filtered to determine the target step height measurement value, which can eliminate abnormal values ​​and noise in the measurement data and improve the accuracy and stability of the data. By sampling the acquired measurement curve, obtaining the fitting straight line, and then denoising the actual measurement value, accurate measurement and analysis of the wafer graphic step height can be achieved, which is conducive to the rapid and accurate detection of defective graphic wafers and greatly increases the yield rate of chip production.

[0093] Optionally, the sampling module 320 is specifically used to: smooth the wafer graphic step height measurement curve and the motor movement distance measurement curve to obtain a preprocessed wafer graphic step height measurement curve and a preprocessed motor movement distance measurement curve; perform curve characteristic analysis based on the preprocessed wafer graphic step height measurement curve and the preprocessed motor movement distance measurement curve to determine the sampling frequency; and sample the preprocessed wafer graphic step height measurement curve and the preprocessed motor movement distance measurement curve based on the sampling frequency, respectively, to obtain a preset number of sampled step height measurement values ​​and a preset number of sampled movement distance measurement values.

[0094] Optionally, the fitting module 330 is specifically used to: determine the intercept fitting coefficient corresponding to the fitting straight line based on the intercept fitting formula, the step height measurement values ​​of the preset number of samplings, and the moving distance measurement values ​​of the preset number of samplings; determine the slope fitting coefficient corresponding to the fitting straight line based on the slope fitting formula, the step height measurement values ​​of the preset number of samplings, and the moving distance measurement values ​​of the preset number of samplings, wherein the intercept fitting formula and the slope fitting formula are determined based on a preset fitting algorithm.

[0095] Optionally, the intercept fitting formula is:

[0096]

[0097] Among them, C1 is the intercept fitting coefficient, y i is the measured value of step height, xi is the moving distance measurement value, n is the preset sampling number;

[0098] The slope fitting formula is:

[0099]

[0100] Among them, C2 is the slope fitting coefficient, y i is the measured value of step height, x i is the measured value of the moving distance.

[0101] Optionally, the measurement module 340 includes:

[0102] a fitting value determination unit, configured to determine a step height fitting value based on the intercept fitting coefficient, the slope fitting coefficient and the moving distance measurement value;

[0103] a deviation determining unit, configured to determine a noise vibration deviation based on the step height fitting value and the step height measurement value;

[0104] The target measurement unit is used to process the step height measurement value based on the noise vibration deviation to determine a target step height measurement value.

[0105] Optionally, the deviation determination unit is specifically used to: determine the difference between the step height fitting value and the step height measurement value corresponding to each sampling point as the noise vibration deviation corresponding to each sampling point, and obtain the noise vibration deviation of a preset number of samplings.

[0106] Optionally, the target measurement unit is specifically used to: determine a step height measurement mean based on a preset number of sampled step height measurement values; determine a noise vibration deviation mean based on a preset number of sampled noise vibration deviations; and subtract the step height measurement mean from the noise vibration deviation mean to determine a target step height measurement value.

[0107] The wafer pattern step height measurement device provided in the embodiment of the present invention can execute the wafer pattern step height measurement method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0108] Figure 7A schematic diagram of the structure of an electronic device 12 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as desktop computers, workstations, servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0109] like Figure 7 As shown, the electronic device 12 is in the form of a general purpose computing device. The components of the electronic device 12 may include, but are not limited to: one or more processors or processing units 16, a system memory 28, and a bus 18 that connects various system components (including the system memory 28 and the processing unit 16).

[0110] Bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor or a local bus using any of a variety of bus architectures. By way of example, these architectures include, but are not limited to, an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MAC) bus, an Enhanced ISA bus, a Video Electronics Standards Association (VESA) local bus, and a Peripheral Component Interconnect (PCI) bus.

[0111] The electronic device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the electronic device 12, including volatile and non-volatile media, removable and non-removable media.

[0112] The system memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. The electronic device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 34 may be used to read and write non-removable, non-volatile magnetic media ( Figure 7 not shown, usually called a "hard drive"). Although Figure 7Not shown in the figure, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk"), and an optical disk drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, a DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to the bus 18 via one or more data medium interfaces. The system memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to perform the functions of the various embodiments of the present invention.

[0113] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in system memory 28, such program modules 42 including, but not limited to, an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment. Program modules 42 generally perform the functions and / or methods of the embodiments described herein.

[0114] The electronic device 12 may also communicate with one or more external devices 14 (e.g., keyboards, pointing devices, displays 24, etc.), may communicate with one or more devices that enable a user to interact with the electronic device 12, and / or may communicate with any device that enables the electronic device 12 to communicate with one or more other computing devices (e.g., network cards, modems, etc.). Such communication may be performed via an input / output (I / O) interface 22. Furthermore, the electronic device 12 may also communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter 20. As shown, the network adapter 20 communicates with other modules of the electronic device 12 via a bus 18. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device 12, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0115] The processing unit 16 executes various functional applications and data processing by running the program stored in the system memory 28, for example, implementing a wafer pattern step height measurement method provided by the embodiment of the present invention, the method comprising:

[0116] Obtain wafer pattern step height measurement curve and motor moving distance measurement curve;

[0117] The wafer pattern step height measurement curve and the motor moving distance measurement curve are sampled respectively to obtain a preset number of sampled step height measurement values ​​and a preset number of sampled moving distance measurement values;

[0118] Performing straight line fitting based on the step height measurement values ​​of the preset number of samplings and the moving distance measurement values ​​of the preset number of samplings, and determining the intercept fitting coefficient and the slope fitting coefficient in the fitted straight line;

[0119] Based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value, the step height measurement value is filtered to determine a target step height measurement value.

[0120] Of course, those skilled in the art can understand that the processor can also implement the technical solution of the data processing method provided by any embodiment of the present invention.

[0121] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the steps of the wafer pattern step height measurement method provided in any embodiment of the present invention are implemented. The method includes:

[0122] Obtain wafer pattern step height measurement curve and motor moving distance measurement curve;

[0123] The wafer pattern step height measurement curve and the motor moving distance measurement curve are sampled respectively to obtain a preset number of sampled step height measurement values ​​and a preset number of sampled moving distance measurement values;

[0124] Performing straight line fitting based on the step height measurement values ​​of the preset number of samplings and the moving distance measurement values ​​of the preset number of samplings, and determining the intercept fitting coefficient and the slope fitting coefficient in the fitted straight line;

[0125] Based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value, the step height measurement value is filtered to determine a target step height measurement value.

[0126] The computer storage medium of the embodiment of the present invention can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to: an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it.

[0127] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0128] The program code embodied on the computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0129] Computer program code for performing the operations of the present invention may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0130] It should be understood by those skilled in the art that the modules or steps of the present invention described above can be implemented by a general-purpose computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, optionally, they can be implemented by a program code executable by a computer device, so that they can be stored in a storage device and executed by the computing device, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.

[0131] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for measuring wafer pattern step height, characterized in that: include: Obtain wafer pattern step height measurement curve and motor moving distance measurement curve; The wafer pattern step height measurement curve and the motor moving distance measurement curve are sampled respectively to obtain a preset number of sampled step height measurement values ​​and a preset number of sampled moving distance measurement values; Performing straight line fitting based on the step height measurement values ​​of the preset number of samplings and the moving distance measurement values ​​of the preset number of samplings, and determining the intercept fitting coefficient and the slope fitting coefficient in the fitted straight line; Based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value, the step height measurement value is filtered to determine a target step height measurement value.

2. The method according to claim 1, characterized in that The step of sampling the wafer pattern step height measurement curve and the motor moving distance measurement curve respectively to obtain a preset number of step height measurement values ​​and a preset number of moving distance measurement values ​​comprises: Smoothing the wafer pattern step height measurement curve and the motor moving distance measurement curve to obtain a pre-processed wafer pattern step height measurement curve and a pre-processed motor moving distance measurement curve; Based on the pre-processed wafer pattern step height measurement curve and the pre-processed motor movement distance measurement curve, the curve characteristics are analyzed to determine the sampling frequency; Based on the sampling frequency, the preprocessed wafer graphic step height measurement curve and the preprocessed motor moving distance measurement curve are sampled respectively to obtain a preset number of sampled step height measurement values ​​and a preset number of sampled moving distance measurement values.

3. The method according to claim 1, characterized in that The step height measurement values ​​based on the preset number of samples and the moving distance measurement values ​​based on the preset number of samples are used to perform straight line fitting, and determine the intercept fitting coefficient and the slope fitting coefficient in the fitted straight line, including: Determine the intercept fitting coefficient corresponding to the fitting straight line based on the intercept fitting formula, the step height measurement values ​​of the preset number of samplings, and the moving distance measurement values ​​of the preset number of samplings; Based on the slope fitting formula, the step height measurement values ​​of the preset sampling number and the moving distance measurement values ​​of the preset sampling number, the slope fitting coefficient corresponding to the fitting straight line is determined, wherein the intercept fitting formula and the slope fitting formula are determined based on a preset fitting algorithm.

4. The method according to claim 3, characterized in that The intercept fitting formula is: Among them, C1 is the intercept fitting coefficient, y i is the measured value of step height, x i is the moving distance measurement value, n is the preset sampling number; The slope fitting formula is: Among them, C2 is the slope fitting coefficient, y i is the measured value of step height, x i is the measured value of the moving distance.

5. The method according to claim 1, characterized in that The filtering process is performed on the step height measurement value based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value to determine the target step height measurement value, including: Determining a step height fitting value based on the intercept fitting coefficient, the slope fitting coefficient and the moving distance measurement value; Determining a noise vibration deviation based on the step height fitting value and the step height measurement value; Based on the noise vibration deviation, the step height measurement value is processed to determine a target step height measurement value.

6. The method according to claim 5, characterized in that Determining a noise vibration deviation based on the step height fitting value and the step height measurement value includes: The difference between the step height fitting value and the step height measurement value corresponding to each sampling point is determined as the noise vibration deviation corresponding to each sampling point, and the noise vibration deviation of a preset number of samplings is obtained.

7. The method according to claim 5, characterized in that The step height measurement value is processed based on the noise vibration deviation to determine the target step height measurement value, including: Determine a step height measurement mean based on a preset number of step height measurement values; Determine a noise vibration deviation mean based on the noise vibration deviation of a preset number of samples; The step height measurement mean is subtracted from the noise vibration deviation mean to determine a target step height measurement value.

8. A wafer pattern step height measuring device, characterized in that: include: A measurement curve acquisition module is used to obtain a wafer pattern step height measurement curve and a motor moving distance measurement curve; A sampling module, used to sample the wafer pattern step height measurement curve and the motor moving distance measurement curve respectively, to obtain a preset number of sampled step height measurement values ​​and a preset number of sampled moving distance measurement values; A fitting module, used to perform straight line fitting based on the step height measurement values ​​of the preset sampling number and the moving distance measurement values ​​of the preset sampling number, and determine the intercept fitting coefficient and the slope fitting coefficient in the fitted straight line; The measurement module is used to filter the step height measurement value based on the intercept fitting coefficient, the slope fitting coefficient, the step height measurement value and the moving distance measurement value to determine the target step height measurement value.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the wafer graphic step height measurement method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the wafer graphic step height measurement method according to any one of claims 1 to 7 when executed.

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