Etching machine parameter calibration method and device, control equipment and calibration system

Abstract

This invention provides a method, apparatus, control device, and calibration system for calibrating etching machine parameters. The method includes: obtaining the certificate value of a micro / nano standard sample; measuring the micro / nano standard sample using a micro / nano geometric measurement instrument to obtain the measured value of the micro / nano standard sample; determining a correction coefficient for the micro / nano geometric measurement instrument based on the measured value and the certificate value of the micro / nano standard sample, and correcting the micro / nano geometric measurement instrument according to the correction coefficient; and calibrating the etching machine parameters using the corrected micro / nano geometric measurement instrument. This invention can improve the accuracy of etching machine operation.

Description

Technical Field

[0001] This invention relates to the field of etching machine parameter technology, and in particular to an etching machine parameter calibration method, apparatus, control equipment and calibration system. Background Technology

[0002] Chip fabrication involves processes such as oxidation, photolithography, etching, and ion implantation. Etching is a crucial step in semiconductor preparation and micro / nano manufacturing. It removes portions of the underlying material not covered by the mask material using physical, chemical, or combined methods, creating a pattern on the etched material surface that matches the mask pattern. As a critical step in semiconductor processing, etching determines the quality of subsequent processes and ultimately affects the overall performance of the device. It is primarily divided into wet etching and dry etching.

[0003] The etching process is primarily completed using an etching machine, a core piece of equipment in the manufacturing of chips such as integrated circuits and microwave power devices. Its performance determines the chip's manufacturing quality. To achieve optimal etching results, the relevant parameters of the etching machine need to be calibrated. Etching machines are process equipment in the semiconductor field, with complex internal structures. Their operation often requires conditions such as vacuum and low pressure, making it impossible to calibrate their parameters using traditional direct measurement methods.

[0004] Most existing technologies use process verification to verify the relevant parameters of the etching machine. However, this method focuses on verifying the process stability of the etching machine equipment, and cannot guarantee the accuracy of the relevant parameters of the etching machine. Summary of the Invention

[0005] This invention provides a method, apparatus, control device, and calibration system for calibrating etching machine parameters, in order to address the problem that most existing technologies focus on verifying the process stability of etching machine equipment, but cannot guarantee the accuracy of the relevant parameters of the etching machine.

[0006] In a first aspect, embodiments of the present invention provide an etching machine parameter calibration method, comprising:

[0007] Obtain the certificate value for micro / nano standard samples;

[0008] The micro-nano standard sample was measured using a micro-nano geometric measurement instrument to obtain the measured value of the micro-nano standard sample;

[0009] The correction factor for the micro-nano geometric measuring instrument is determined based on the measured value and certificate value of the micro-nano standard template, and the micro-nano geometric measuring instrument is corrected based on the correction factor.

[0010] The parameters of the etching machine were calibrated using a modified micro-nano geometric measurement instrument.

[0011] In one possible implementation, the micro / nano standard template includes a micro / nano film thickness standard template;

[0012] Correspondingly, the certificate value of the micro / nano standard sample includes the certificate film thickness value of the micro / nano film thickness standard sample;

[0013] Micro- and nano-geometric measurement instruments include ellipsometers;

[0014] Correspondingly, the measurements of the micro / nano standard templates include the polarization angle and phase difference of the micro / nano film thickness templates.

[0015] In one possible implementation, the correction factor for the micro-nano geometric measurement instrument is determined based on the measured value and the certified value of the micro-nano standard template, including:

[0016] The measured film thickness value of the micro / nano film thickness standard template is determined based on the polarization angle and phase difference of the template, as well as the predetermined film thickness ellipticity relationship.

[0017] The correction coefficient of the ellipsometer is determined by the measured film thickness value of the micro / nano film thickness standard template and the film thickness certificate value of the micro / nano film thickness standard template.

[0018] In one possible implementation, the parameters of the etching machine are calibrated using a modified micro / nano geometry measurement instrument, including:

[0019] The film thickness of the experimental sample before etching by the etching machine was measured using a modified micro-nano geometric measurement instrument to obtain the first film thickness value.

[0020] The film thickness of the experimental sample after etching by the etching machine was measured using a modified micro-nano geometric measurement instrument to obtain a second film thickness value.

[0021] The actual etching rate and etching uniformity of the etching machine are calculated based on the first film thickness value and the second film thickness value.

[0022] The parameters of the etching machine are calibrated based on the actual etching rate and etching uniformity.

[0023] In one possible implementation, the micro / nano standard template includes a micro / nano grating standard template;

[0024] Correspondingly, the certificate value of micro-nano standard templates includes the certificate value of micro-nano grating standard templates;

[0025] Micro- and nano-geometric measurement instruments include scanning electron microscopes;

[0026] Correspondingly, the measured values ​​of the micro-nano standard templates include the measured line spacing values ​​of the micro-nano grating standard templates.

[0027] In one possible implementation, the correction factor for the micro-nano geometric measurement instrument is determined based on the measured value and the certified value of the micro-nano standard template, including:

[0028] The correction factor for scanning electron microscope measuring instruments is determined based on the measured line spacing value and the certificate value of the micro / nano grating standard template.

[0029] Secondly, embodiments of the present invention provide an etching machine parameter calibration device, comprising:

[0030] The acquisition module is used to obtain the certificate value of the micro / nano standard template;

[0031] The measurement module is used to measure micro-nano standard samples using micro-nano geometric measurement instruments to obtain the measured values ​​of the micro-nano standard samples;

[0032] The correction module is used to determine the correction coefficient of the micro-nano geometric measuring instrument based on the measured value and certificate value of the micro-nano standard template, and to correct the micro-nano geometric measuring instrument according to the correction coefficient.

[0033] The calibration module is used to calibrate the parameters of the etching machine using a modified micro-nano geometric measurement instrument.

[0034] Thirdly, embodiments of the present invention provide a control device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the etching machine parameter calibration method as described in the first aspect or any possible implementation of the first aspect.

[0035] Fourthly, embodiments of the present invention provide an etching machine calibration system, including the control device as described in the third aspect above, a scanning electron microscope measuring instrument, and an ellipsometer; wherein the scanning electron microscope measuring instrument and the ellipsometer are both controlled by the control device.

[0036] Fifthly, embodiments of the present invention provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the etching machine parameter calibration method as described in the first aspect or any possible implementation of the first aspect.

[0037] This invention provides a method, apparatus, control device, and calibration system for calibrating etching machine parameters. The method involves: obtaining the certificate value of a micro / nano standard sample; measuring the micro / nano standard sample using a micro / nano geometric measurement instrument to obtain its measured value; determining a correction coefficient for the micro / nano geometric measurement instrument based on its measured value and certificate value; and correcting the micro / nano geometric measurement instrument using the corrected coefficient. The calibration of the etching machine parameters using the corrected micro / nano geometric measurement instrument improves the accuracy and reliability of the etching machine's operation. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram illustrating the etching deviation provided in an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of transverse drilling provided in an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of the etching rate provided in an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of etching uniformity measurement provided in an embodiment of the present invention;

[0043] Figure 5 This is a flowchart illustrating the implementation of the etching machine parameter calibration method provided in this embodiment of the invention.

[0044] Figure 6 This is a schematic diagram of the elliptic polarization optical path provided in an embodiment of the present invention;

[0045] Figure 7 This is a schematic diagram illustrating the geometric relationship between the elliptical azimuth angle, polarization angle, and phase difference provided in an embodiment of the present invention;

[0046] Figure 8 This is a schematic diagram of the etching machine parameter calibration device provided in an embodiment of the present invention;

[0047] Figure 9 This is a schematic diagram of the control device provided in an embodiment of the present invention. Detailed Implementation

[0048] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0049] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0050] See Figure 1 This illustrates a schematic diagram of etching deviations provided in an embodiment of the present invention; see also Figure 2 It shows a schematic diagram of transverse drilling provided in an embodiment of the present invention; see also Figure 3 This diagram illustrates the etching rate provided in an embodiment of the present invention; see also... Figure 4 This diagram illustrates a measurement schematic of etching uniformity provided in an embodiment of the present invention.

[0051] Key parameters reflecting the performance of an etching machine include etching deviation, etching rate, and etching uniformity. In practical applications, these three key parameters can be accurately calculated by setting relevant parameters of the etching machine. The following is an explanation of these three key parameters:

[0052] (1) Etching deviation: refers to the change in linewidth or critical dimension spacing after the material is etched, such as Figure 1 As shown, the accuracy of the etchable line width by the etching machine is characterized by calculation; it is usually caused by lateral drilling, but can also be caused by the etching profile. After configuring the etching machine process parameters, when excessive material under the mask is etched away, the upper surface of the etched material will be recessed towards the mask edge, thus producing lateral drilling, such as... Figure 2 As shown. The etching deviation can be calculated using the following formula:

[0053] Etching deviation = W a -W b

[0054] Among them, W a W represents the linewidth of the photoresist before etching. b The linewidth of the etched material after the photoresist is removed.

[0055] (2) Etching rate: refers to the depth of etching or the thickness removed per unit time. It is characterized by monitoring the step height or film thickness of the etched material. A schematic diagram of the etching rate is shown below. Figure 3As shown. The etching rate is determined by both the etching process and equipment conditions, such as the properties of the material being etched, the structure of the instrument, the gas used in the etching experiment, and the process parameter settings. The etching rate can be calculated using the following formula:

[0056] Etching rate = ΔT / t

[0057] Where ΔT is the thickness of the material removed, and t is the etching time.

[0058] (3) Etching Uniformity: The uniformity of the thickness of the thin film layer removed or the depth of the etched trenches on the substrate surface, generally including intra-wafer uniformity, inter-wafer uniformity, and batch uniformity. A lower etching uniformity value indicates that the material removal rate is consistent across the wafer surface, and the thickness of the etched material is approximately uniform, indicating a better etching effect. For intra-wafer uniformity, it is necessary to measure the etching depth data at different points within the wafer. Typical test points include... Figure 4 As shown. Etching uniformity is characterized by monitoring the step height or film thickness at different locations in the etched area. Etching uniformity can be calculated using the following formula;

[0059]

[0060] T i The measured value, or the average of the measured values ​​per piece (between pieces), or the average of the measured values ​​per batch (between batches); This is the average value. n represents the number of measurement points (within a slice), the number of slices measured (between slices), or the number of batches measured (between batches).

[0061] To achieve the best etching results, it is necessary to calibrate three key parameters of the etching machine: etching deviation, etching rate, and etching uniformity. This calibration technique guides the improvement of the etching machine's process parameters, ultimately optimizing product performance indicators.

[0062] See Figure 5 The diagram illustrates the implementation flowchart of the etching machine parameter calibration method provided in this embodiment of the invention. Figure 5 As shown, an etching machine parameter calibration method may include:

[0063] S101, obtain the certificate value of the micro / nano standard sample;

[0064] Optionally, micro-nano standard templates may include micro-nano linewidth standard templates, micro-nano film thickness standard templates, micro-nano one-dimensional grating standard templates, micro-nano two-dimensional grating standard templates, etc., and the certificate value is the standard value specified by various micro-nano standard templates.

[0065] S102, use a micro-nano geometric measurement instrument to measure a micro-nano standard sample and obtain the measured value of the micro-nano standard sample;

[0066] Optionally, micro- and nano-geometric measuring instruments may include scanning electron microscopes or ellipsometers.

[0067] Specifically, scanning electron microscopes can measure micro / nano linewidth standard templates, micro / nano one-dimensional grating standard templates, and micro / nano two-dimensional grating standard templates to obtain the relevant measurement values ​​of the micro / nano standard templates; ellipsometers can measure micro / nano film thickness standard templates to obtain the relevant measurement values.

[0068] S103, determine the correction coefficient of the micro-nano geometric measuring instrument based on the measured value and certificate value of the micro-nano standard template, and correct the micro-nano geometric measuring instrument based on the correction coefficient;

[0069] Optionally, the correction factor is used to characterize the deviation value of the micro-nano geometric measurement instrument. The correction factor of the micro-nano geometric measurement instrument can be calculated by using the certificate value of the micro-nano standard template and the measurement value of the micro-nano geometric measurement instrument.

[0070] Specifically, the correction factor for micro / nano geometric measurement instruments can be the ratio of the measured value to the certificate value, or the difference between the measured value and the certificate value, etc. Furthermore, to ensure the reliability of the correction factor, the instrument can be used to measure micro / nano standard samples multiple times, calculate the correction factor multiple times, and then average the results as the correction factor for the instrument. This ensures the reliability of the results, and consequently, the reliability of the etching machine parameter calibration.

[0071] S104, the parameters of the etching machine are calibrated using a modified micro-nano geometric measurement instrument.

[0072] Optionally, the sample to be tested can be etched using an etching machine. The measured values ​​of the sample before and after etching can be measured using a modified micro-nano geometric measurement instrument. The parameters of the etching machine can be calculated and compared with the parameters of the etching machine itself, thereby calibrating the parameters of the etching machine.

[0073] Specifically, the parameters of the etching machine can include etching deviation. The corrected micro / nano geometry measuring instrument measures the sample before and after etching to obtain the measured values, and calculates the first etching deviation of the etching machine. The etching machine itself can obtain the etching deviation of the sample through set data, denoted as the second etching deviation. By comparing the first and second etching deviations, and using the first etching deviation as a benchmark, the parameters of the etching machine are calibrated.

[0074] This invention involves obtaining the certificate value of a micro / nano standard sample; measuring the micro / nano standard sample using a micro / nano geometric measurement instrument to obtain its measurement value; determining the correction coefficient of the micro / nano geometric measurement instrument based on its measurement value and certificate value; correcting the micro / nano geometric measurement instrument based on the correction coefficient; and calibrating the parameters of the etching machine using the corrected micro / nano geometric measurement instrument. After calibrating the etching machine's parameters, the accuracy and reliability of the etching machine's operation can be improved.

[0075] In some embodiments of the present invention, the micro / nano standard template includes a micro / nano film thickness standard template;

[0076] Correspondingly, the certificate value of the micro / nano standard sample includes the certificate film thickness value of the micro / nano film thickness standard sample;

[0077] Micro- and nano-geometric measurement instruments include ellipsometers;

[0078] Correspondingly, the measurements of the micro / nano standard templates include the polarization angle and phase difference of the micro / nano film thickness templates.

[0079] In some embodiments of the present invention, the step of "determining the correction coefficient of the micro-nano geometric measurement instrument based on the measured value of the micro-nano standard template and the certificate value of the micro-nano standard template" in S103 above may include:

[0080] The measured film thickness value of the micro / nano film thickness standard template is determined based on the polarization angle and phase difference of the template, as well as the predetermined film thickness ellipticity relationship.

[0081] The correction coefficient of the ellipsometer is determined by the measured film thickness value of the micro / nano film thickness standard template and the film thickness certificate value of the micro / nano film thickness standard template.

[0082] Optionally, the calibration process for the ellipsometer may include:

[0083] An ellipsometer is used to measure the thickness of a micro / nano film sample to obtain its polarization angle and phase difference. The measured thickness of the micro / nano film sample is then calculated based on the polarization angle and phase difference. The measured thickness is compared with the certified thickness of the micro / nano film sample to determine the correction coefficient of the ellipsometer. The ellipsometer is then corrected according to the correction coefficient.

[0084] Optionally, the micro / nano film thickness standard template can be a silicon dioxide thin film on silicon. Micro / nano geometric measurement instruments may include metrological atomic force microscopes.

[0085] For example, the process of calculating the thickness of a silicon dioxide thin film on silicon using an ellipsometry can be as follows:

[0086] (1) A stepped structure is formed by etching a silicon dioxide thin film on silicon.

[0087] (2) The height of the step was obtained by measuring the step structure using a metrological atomic force microscope.

[0088] (3) Use an ellipsometry to measure the silicon dioxide film on silicon, wherein the measured thickness is fixed to the step height in step (1).

[0089] (4) The dispersion parameters of the silicon dioxide thin film on silicon are determined by using discrete sampling and the difference method. The dispersion parameters include the film thickness and refractive index of the silicon dioxide thin film on silicon.

[0090] Specifically, the dispersion parameters can be determined based on the principle of ellipsometric light path and the characteristics of thin film reflection forming ellipsometric light.

[0091] See Figure 6 It shows a schematic diagram of the elliptic polarization optical path provided in an embodiment of the present invention; as follows: Figure 6 As shown, where E ip For the incident light p component, E is E represents the s-component of the incident light. rp E represents the p-component of the reflected light. rs Let θ0 be the s-component of the reflected light, θ1 be the angle of incidence in the air, θ2 be the angle of refraction in the substrate, n0 be the refractive index of air, n1 be the refractive index of the thin film, d1 be the thickness of the thin film, and n2 be the refractive index of the substrate.

[0092] See Figure 7 This diagram illustrates the geometric relationship between the elliptical azimuth angle, polarization angle, and phase difference provided in an embodiment of the present invention. Figure 7 As shown, Ψ is the polarization angle, β is the azimuth angle of the ellipse in the s and p coordinate systems, a is the radius of the major axis of the ellipse, b is the radius of the minor axis of the ellipse, and r is the polarization angle. s Let r be the magnitude of the amplitude reflection coefficient in the s-polarization direction. p Let be the magnitude of the amplitude reflection coefficient in the p-polarization direction.

[0093] The characteristics of elliptically polarized light formed by thin film reflection are represented using the thin film ellipticity function, and the specific formula is as follows:

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102] Where ρ is an elliptic function of the thin film. Let be the amplitude reflection coefficient in the p-polarization direction. Let r be the amplitude reflection coefficient in the s-polarization direction. p Let r be the magnitude of the amplitude reflection coefficient in the p-polarization direction. s Let be the magnitude of the amplitude reflection coefficient in the s-polarization direction. For p-polarized phase, Let s be the polarization phase, Ψ be the polarization angle, Δ be the phase difference, and r be the polarization phase. 1s Let r be the Fresnel reflection coefficient of the s-direction polarization component of interface 1. 2s Let δ1 be the Fresnel reflection coefficient of the s-direction polarization component of interface 2, θ0 be the incident angle in air, θ1 be the incident angle in the thin film, θ2 be the refraction angle in the substrate, n0 be the refractive index of air, n1 be the refractive index of the thin film, d1 be the thickness of the thin film, n2 be the refractive index of the substrate, and r be the refractive index of the substrate. 1p Let r be the Fresnel reflection coefficient of the p-direction polarization component of interface 1. 2p Let λ be the Fresnel reflection coefficient of the p-direction polarization component of interface 2, and λ be the wavelength of light in vacuum.

[0103] Clearly, Ψ and Δ are functions of d1, n0, n1, n2, θ0, θ2, and λ, where n0, n2, θ0, θ2, and λ are known parameters. By measuring Ψ and Δ using an ellipsometer, a measurement model can be established. Through fitting and solving, the refractive index and thickness of the measured sample (i.e., the silicon dioxide thin film on silicon) can be obtained.

[0104] For example, the M2000VF ellipsometer was corrected using a standard sample with a film thickness of 20nm to 1000nm. The measurement data are shown in Table 1.

[0105] Table 1

[0106]

[0107] In some embodiments of the present invention, the above-mentioned S104 "calibrating the parameters of the etching machine using a modified micro-nano geometric measurement instrument" may include:

[0108] The film thickness of the experimental sample before etching by the etching machine was measured using a modified micro-nano geometric measurement instrument to obtain the first film thickness value.

[0109] The film thickness of the experimental sample after etching by the etching machine was measured using a modified micro-nano geometric measurement instrument to obtain a second film thickness value.

[0110] The actual etching rate and etching uniformity of the etching machine are calculated based on the first film thickness value and the second film thickness value.

[0111] The parameters of the etching machine are calibrated based on the actual etching rate and etching uniformity.

[0112] Optionally, the film thickness test sample can be a Si substrate or a substrate of other semiconductors.

[0113] Before etching the sample to be tested, the film thickness is first measured and calculated using a corrected ellipsometry, and recorded as the first film thickness value. After etching, the second film thickness value is calculated again using the corrected ellipsometry. Based on the first and second film thickness values, the actual etching rate and actual etching uniformity can be calculated using the etching rate formula and etching uniformity calculation formula.

[0114] The etching rate and etching uniformity can also be calculated based on the parameters of the etching machine. By comparing the two, the actual etching rate and actual etching uniformity calculated by the ellipsometry can be used to calibrate the parameters of the etching machine, thereby achieving the purpose of calibrating the two key parameters of the etching machine: etching rate and etching uniformity.

[0115] For example, a 3-inch Si substrate was prepared, and SiO2 was deposited on it. The thickness before etching was measured using an ellipsometry. Then, the SiO2 was etched using an 800Plus etching machine according to the etching process specifications for 3 minutes. The SiO2 thickness at five points (center and perimeter) after etching was measured using the same ellipsometry. The etching rate and etching uniformity at each point were calculated. The corrected readings were used to measure the sample, and the measurement data are shown in Table 2.

[0116] Table 2

[0117]

[0118] In some embodiments of the present invention, the micro / nano standard template includes a micro / nano grating standard template;

[0119] Correspondingly, the certificate value of micro-nano standard templates includes the certificate value of micro-nano grating standard templates;

[0120] Micro- and nano-geometric measurement instruments include scanning electron microscopes;

[0121] Correspondingly, the measured values ​​of the micro-nano standard templates include the measured line spacing values ​​of the micro-nano grating standard templates.

[0122] In some embodiments of the present invention, the step of "determining the correction coefficient of the micro-nano geometric measurement instrument based on the measured value of the micro-nano standard template and the certificate value of the micro-nano standard template" in S104 above may further include:

[0123] The correction factor for scanning electron microscope measuring instruments is determined based on the measured line spacing value and the certificate value of the micro / nano grating standard template.

[0124] Optional,

[0125] In some embodiments of the present invention, a comparative measurement calibration method can be used to calibrate scanning electron microscopes.

[0126] For example, the scanning electron microscope (SEM) measuring instrument can be a model S-4800Ⅱ, and the micro / nano grating standard sample can be a grating standard sample with a period of 100 nm. Table 3 shows the relevant information of the grating standard sample with a period of 100 nm.

[0127] Table 3

[0128]

[0129] The correction process can be as follows:

[0130] The magnification of the S-4800Ⅱ scanning electron microscope in the X and Y directions of 50K and 100K was corrected using a grating standard template with a period size of 100nm. The measurement data are shown in Table 4. The measurement data was then used to correct the magnification of the scanning electron microscope.

[0131] Table 4

[0132]

[0133]

[0134] For example, an 800Plus etching machine was used to etch a 3-inch Si substrate sample. The sample was measured using a scanning electron microscope (SEM) in the X direction. The measurement data are shown in Table 5. Among them, -16.2nm is the calculated result before comparative measurement. After the SEM was corrected using a grating standard sample, the calibration result of the etching deviation was -16.0nm. It can be seen that the comparative measurement method can effectively complete the calibration of the etching deviation of the etching machine.

[0135] Table 5

[0136] state Line width Magnification Correction coefficient Actual line width Before etching 702.3nm 100K 0.9892 694.7nm After etching 718.5nm 100K 0.9892 710.7nm Difference -16.2nm / / -16.0nm

[0137] This invention uses micro-nano standard templates and micro-nano geometric measurement instruments as measurement standards for comparative measurement. First, the micro-nano standard templates are measured using micro-nano geometric measurement instruments, and the certificate value of the standard templates is used as the standard value to correct the measurement display value of the micro-nano geometric measurement instruments. Then, the corrected result is used to calibrate the feature pattern size made by the etching mechanism, thereby achieving the purpose of calibrating the key parameters of the etching machine.

[0138] For example, the calibration process of the present invention can be as follows:

[0139] (1) Micro-nano standard templates and micro-nano geometric measurement instruments are used as the measurement standards for comparative measurements. Among them, micro-nano standard templates serve as the main standard instruments, including micro-nano linewidth standard templates, micro-nano grating standard templates, and micro-nano film thickness standard templates, etc.; micro-nano geometric measurement instruments serve as supporting standards, including scanning electron microscopes and ellipsometers, etc.

[0140] (2) Use micro / nano linewidth / grating standard templates and scanning electron microscopes to calibrate etching deviations.

[0141] The certificate value of the micro / nano linewidth standard template or the micro / nano grating standard template is used as the standard value W. 标 First, a scanning electron microscope (SEM) is used to measure the standard sample, and the measured value is recorded as W1. Then, the width of the line to be measured is measured using the same SEM, and the measured value is recorded as W2. The actual value W of the measured line width is calculated using the following formula, thereby calibrating the key parameter of etching deviation of the etching machine. The formula for calculating the actual value W of the measured line width is:

[0142] (3) The etching uniformity and etching rate were calibrated using micro-nano film thickness standard templates and ellipsometry.

[0143] First, the ellipsometer is calibrated and corrected using a micro / nano film thickness standard template. Specifically, the certified value of the film thickness standard template is used as the standard value to correct the ellipsometer reading, ensuring the stability of the ellipsometer hardware. Second, the film thickness of the actual etched product material is calculated based on its characteristics.

[0144] Specifically, for the etched thin film, the open film method is used to determine the film thickness. Then, based on the known film thickness, an ellipsometer is used with discrete sampling to determine the film dispersion model through a difference algorithm, and the film thickness of the actual etched product material is calculated. Finally, the ellipsometer is used to calibrate the etching rate and etching uniformity parameters of the etching machine used to etch the actual etched product, thereby improving the calibration accuracy of the key parameters of etching rate and etching uniformity.

[0145] The present invention proposes a calibration method that uses micro-nano standard templates and micro-nano geometric measurement instruments for standardization and comparative measurement. This method can effectively solve the calibration problems of etching deviation, etching rate and etching uniformity of etching machines, and realize the calibration of key parameters of etching machines and effective traceability of measurement values.

[0146] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0147] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0148] Figure 8 A schematic diagram of the etching machine parameter calibration device provided in an embodiment of the present invention is shown. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below:

[0149] like Figure 8 As shown, the etching machine parameter calibration device 20 may include:

[0150] Module 201 is used to obtain the certificate value of the micro / nano standard sample;

[0151] Measurement module 202 is used to measure micro-nano standard samples using micro-nano geometric measurement instruments to obtain the measured values ​​of micro-nano standard samples;

[0152] The correction module 203 is used to determine the correction coefficient of the micro-nano geometric measuring instrument based on the measured value of the micro-nano standard template and the certificate value of the micro-nano standard template, and to correct the micro-nano geometric measuring instrument based on the correction coefficient.

[0153] The calibration module 204 is used to calibrate the parameters of the etching machine using a modified micro-nano geometric measurement instrument.

[0154] In some embodiments of the present invention, the micro / nano standard template includes a micro / nano film thickness standard template;

[0155] Correspondingly, the certificate value of the micro / nano standard sample includes the certificate film thickness value of the micro / nano film thickness standard sample;

[0156] Micro- and nano-geometric measurement instruments include ellipsometers;

[0157] Correspondingly, the measurements of the micro / nano standard templates include the polarization angle and phase difference of the micro / nano film thickness templates.

[0158] In some embodiments of the present invention, the correction module 203 may include:

[0159] The film thickness calculation unit is used to determine the measured film thickness value of the micro / nano film thickness template based on the polarization angle and phase difference of the micro / nano film thickness standard template and the predetermined film thickness ellipticity relationship.

[0160] The film thickness correction unit is used to determine the correction coefficient of the ellipsometer based on the measured film thickness value of the micro / nano film thickness standard sample and the film thickness certificate value of the micro / nano film thickness standard sample.

[0161] In some embodiments of the present invention, the calibration module 204 may include:

[0162] The first measurement unit is used to measure the film thickness of the experimental sample before it is etched by the etching machine using a modified micro-nano geometric measurement instrument, and to obtain the first film thickness value.

[0163] The second measurement unit is used to measure the film thickness of the experimental sample before it is etched by the etching machine using a modified micro-nano geometric measurement instrument, and to obtain the second film thickness value.

[0164] The calculation unit is used to calculate the actual etching rate and etching uniformity of the etching machine based on the first film thickness value and the second film thickness value;

[0165] The film thickness calibration unit is used to calibrate the parameters of the etching machine based on the actual etching rate and etching uniformity.

[0166] In some embodiments of the present invention, the micro / nano standard template includes a micro / nano grating standard template;

[0167] Correspondingly, the certificate value of micro-nano standard templates includes the certificate value of micro-nano grating standard templates;

[0168] Micro- and nano-geometric measurement instruments include scanning electron microscopes;

[0169] Correspondingly, the measured values ​​of the micro-nano standard templates include the measured line spacing values ​​of the micro-nano grating standard templates.

[0170] In some embodiments of the present invention, the correction module 203 can also be used to determine the correction coefficient of scanning electron microscope measuring instruments based on the measured line spacing value of the micro / nano grating standard template and the certificate value of the micro / nano grating standard template.

[0171] Figure 9 This is a schematic diagram of the control device provided in an embodiment of the present invention. Figure 9 As shown, the control device 30 of this embodiment includes a processor 300, a memory 301, and a computer program 302 stored in the memory 301 and executable on the processor 300. When the processor 300 executes the computer program 302, it implements the steps in the various etching machine parameter calibration method embodiments described above, for example... Figure 5S101 to S104 are shown. Alternatively, when the processor 300 executes the computer program 302, it implements the functions of each module / unit in the above-described device embodiments, for example... Figure 8 The functions of modules / units 201 to 204 shown.

[0172] For example, computer program 302 can be divided into one or more modules / units, one or more of which are stored in memory 301 and executed by processor 300 to complete the present invention. One or more modules / units can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of computer program 302 in control device 30. For example, computer program 302 can be divided into... Figure 8 The modules / units shown are 201 to 204.

[0173] The control device 30 can be a computing device such as a desktop computer, laptop, handheld computer, or cloud server. The control device 30 may include, but is not limited to, a processor 300 and a memory 301. Those skilled in the art will understand that... Figure 9 This is merely an example of the control device 30 and does not constitute a limitation on the control device 30. It may include more or fewer components than shown, or combine certain components, or different components. For example, the control device may also include input / output devices, network access devices, buses, etc.

[0174] The processor 300 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0175] The memory 301 can be an internal storage unit of the control device 30, such as a hard disk or RAM of the control device 30. The memory 301 can also be an external storage device of the control device 30, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the control device 30. Furthermore, the memory 301 can include both internal and external storage units of the control device 30. The memory 301 is used to store computer programs and other programs and data required by the control device. The memory 301 can also be used to temporarily store data that has been output or will be output.

[0176] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0177] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0178] This invention also provides an etching machine calibration system, including the control device 30, a scanning electron microscope (SEM) measuring instrument, and an ellipsometry as described above; wherein the SEM measuring instrument 40 and the ellipsometry are both controlled by the control device. The control device 30 can control the SEM measuring instrument to calibrate the etching deviation of the etching machine, and the control device 30 can control the ellipsometry to calibrate the etching rate and etching uniformity of the etching machine.

[0179] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0180] In the embodiments provided by this invention, it should be understood that the disclosed apparatus / control devices and methods can be implemented in other ways. For example, the apparatus / control device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0181] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0182] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0183] If integrated modules / units are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various etching machine parameter calibration method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0184] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for calibrating etching machine parameters, characterized in that, include: Obtain the certificate value for micro / nano standard samples; The micro-nano standard sample is measured using a micro-nano geometric measurement instrument to obtain the measured value of the micro-nano standard sample; The correction factor of the micro-nano geometric measuring instrument is determined based on the measured value of the micro-nano standard template and the certificate value of the micro-nano standard template, and the micro-nano geometric measuring instrument is corrected based on the correction factor; The parameters of the etching machine were calibrated using a modified micro-nano geometric measurement instrument; The micro / nano standard template includes a micro / nano film thickness standard template; correspondingly, the certificate value of the micro / nano standard template includes the certificate film thickness value of the micro / nano film thickness standard template; the micro / nano geometric measurement instrument includes an ellipsometer; correspondingly, the measurement value of the micro / nano standard template includes the polarization angle and phase difference of the micro / nano film thickness template; The step of determining the correction coefficient of the micro-nano geometric measurement instrument based on the measured value and certificate value of the micro-nano standard template includes: determining the measured film thickness value of the micro-nano film thickness template based on the polarization angle and phase difference of the micro-nano film thickness standard template and a predetermined film thickness ellipticity relation; and determining the correction coefficient of the ellipticity meter based on the measured film thickness value and certificate value of the micro-nano film thickness standard template. The calibration of the etching machine parameters using a modified micro / nano geometric measurement instrument includes: The film thickness of the experimental sample before etching by the etching machine is measured using a corrected ellipsometer to obtain a first film thickness value; the film thickness of the experimental sample after etching by the etching machine is measured using the corrected ellipsometer to obtain a second film thickness value; based on the first film thickness value and the second film thickness value, the actual etching rate and actual etching uniformity of the etching machine are calculated and compared with the etching rate and etching uniformity of the etching machine itself; the parameters of the etching machine are calibrated based on the actual etching rate and etching uniformity of the etching machine to calibrate the etching rate and etching uniformity of the etching machine.

2. The etching machine parameter calibration method according to claim 1, characterized in that, The micro-nano standard template also includes a micro-nano grating standard template; Accordingly, the certificate value of the micro / nano standard template includes the certificate value of the micro / nano grating standard template; The micro-nano geometric measurement instruments include scanning electron microscopes; Accordingly, the measured values ​​of the micro-nano standard template include the measured line spacing values ​​of the micro-nano grating standard template; The step of determining the correction factor of the micro-nano geometric measurement instrument based on the measured value and the certificate value of the micro-nano standard template includes: The correction factor for the scanning electron microscope measuring instrument is determined based on the measured line spacing value of the micro / nano grating standard template and the certificate value of the micro / nano grating standard template. The calibration of the etching machine parameters using a modified micro / nano geometric measurement instrument includes: The linewidth of the sample before etching and the linewidth of the sample after etching are measured using a modified scanning electron microscope-type measuring instrument. The first etching deviation of the etching machine is calculated. The etching machine itself can obtain the etching deviation of the sample through set data, which is recorded as the second etching deviation. By comparing the first etching deviation and the second etching deviation, the parameters of the etching machine are calibrated with the first etching deviation as a reference to adjust the etching deviation of the etching machine.

3. An etching machine parameter calibration device, characterized in that, include: The acquisition module is used to obtain the certificate value of the micro / nano standard template; The measurement module is used to measure the micro-nano standard sample using a micro-nano geometric measurement instrument to obtain the measured value of the micro-nano standard sample; The correction module is used to determine the correction coefficient of the micro-nano geometric measuring instrument based on the measured value of the micro-nano standard template and the certificate value of the micro-nano standard template, and to correct the micro-nano geometric measuring instrument based on the correction coefficient. The calibration module is used to calibrate the parameters of the etching machine using a modified micro-nano geometry measurement instrument; The micro / nano standard template includes a micro / nano film thickness standard template; correspondingly, the certificate value of the micro / nano standard template includes the certificate film thickness value of the micro / nano film thickness standard template; the micro / nano geometric measurement instrument includes an ellipsometer; correspondingly, the measurement value of the micro / nano standard template includes the polarization angle and phase difference of the micro / nano film thickness template; The step of determining the correction coefficient of the micro-nano geometric measurement instrument based on the measured value and certificate value of the micro-nano standard template includes: determining the measured film thickness value of the micro-nano film thickness template based on the polarization angle and phase difference of the micro-nano film thickness standard template and a predetermined film thickness ellipticity relation; and determining the correction coefficient of the ellipticity meter based on the measured film thickness value and certificate value of the micro-nano film thickness standard template. The calibration of the etching machine parameters using a modified micro-nano geometric measurement instrument includes: measuring the film thickness of the experimental sample before etching by the etching machine using a modified ellipsometry to obtain a first film thickness value; measuring the film thickness of the experimental sample after etching by the etching machine using a modified ellipsometry to obtain a second film thickness value; calculating the actual etching rate and actual etching uniformity of the etching machine based on the first film thickness value and the second film thickness value, and comparing them with the etching rate and etching uniformity of the etching machine itself; calibrating the parameters of the etching machine based on the actual etching rate and etching uniformity of the etching machine to calibrate the etching rate and etching uniformity of the etching machine.

4. A control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the etching machine parameter calibration method as described in any one of claims 1 to 2.

5. An etching machine calibration system, characterized in that, It includes the control device, scanning electron microscope measuring instrument, and ellipsometer as described in claim 4; wherein the scanning electron microscope measuring instrument and the ellipsometer are both controlled by the control device.

6. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the etching machine parameter calibration method as described in any one of claims 1 to 2 above.

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