A photolithography process for IC chip quartz substrate with reduced photolithography distortion

Abstract

The present invention discloses an IC chip quartz substrate photolithography process for reducing photolithography distortion, relates to the field of IC chip photolithography technology, and aims to solve the problem of poor pattern accuracy during photolithography. The present invention uses the PSM technology to perform phase shift design on the photolithography pattern, which can further enhance the contrast of the photolithography pattern, reduce the halo effect in the photolithography process, make the edge of the pattern clearer and sharper, and help achieve a smaller line width and a higher pattern density. In the phase shift pattern design, the photolithography effect can be further optimized by adding auxiliary graphics, accurately controlling the position and size of the phase shift area, and setting a reasonable phase shift value.

Description

Technical Field

[0001] The invention relates to the technical field of IC chip photolithography, in particular to an IC chip quartz substrate photolithography process for reducing photolithography distortion. Background Art

[0002] In the IC chip manufacturing process, photolithography technology is required to draw patterns. For example, the patent application with the publication number CN117369214A discloses a photolithography coating process with controllable coating thickness for quartz substrate production. The process mainly uses the first stage of variable speed coating to quickly flatten the photoresist on the quartz substrate, prevent the appearance of reticulation on the edge of the quartz substrate, ensure the flatness and uniformity of the first layer of the quartz substrate, detect the thickness of the first layer of the film using an infrared micrometer, calculate and set the rotation speed based on the detected thickness of the first layer of the film, and adjust the speed for different quartz substrates in a targeted manner to ensure that the film thickness error range is within 5%. When the thickness of the first layer of the film is within the set range, a second layer of the film is coated on the basis of the first layer of the film. The coating speed of the second layer of the film is slower. At this time, the second layer of the film is pressed by an air pressure of 100Pa-120Pa to ensure that the overall surface is smoother on the basis of the thick film layer, thereby achieving the uniformity of the entire film layer. Although the above patent solves the coating process of the quartz substrate, the following problems still exist during photolithography:

[0003] 1. Targeted equipment optical optimization is not performed based on the different distortion performance of each lithography equipment, resulting in a longer lithography process cycle and reduced lithography accuracy.

[0004] 2. Different mask designs are not made according to the differences in lithography equipment, resulting in the inability to more accurately lithography the lithography pattern.

[0005] 3. After the mask is designed, the designed mask is not saved according to its characteristics, and when the IC chip quartz substrate is photolithographic, the photolithography process is not monitored in real time, resulting in the inability to obtain the photolithography process parameters more accurately. Summary of the invention

[0006] The purpose of the present invention is to provide an IC chip quartz substrate lithography process that reduces lithography distortion. By using the PSM technology to perform phase shift design on the lithography pattern, the contrast of the lithography pattern can be further enhanced and the halo effect in the lithography process can be reduced. By selecting a suitable photoresist and carefully setting its performance parameters, the distortion in the lithography process can be effectively reduced, and the problems in the prior art can be solved.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] An IC chip quartz substrate photolithography process for reducing photolithography distortion comprises the following steps:

[0009] S1: Quartz substrate lithography equipment confirmation: Before the IC chip quartz substrate is lithographically processed, the lithography equipment must be prepared and tested;

[0010] S2: Optical optimization of lithography equipment: Optical optimization and adjustment of the inspected lithography equipment according to the equipment characteristics;

[0011] S3: Photolithography mask design: After the photolithography equipment is optically optimized and adjusted, the adjusted photolithography equipment is used for mask design;

[0012] S4: Environmental temperature control: After the mask design is completed, the lithography equipment is temperature controlled;

[0013] S5: Quartz substrate lithography monitoring: After temperature control, the IC chip quartz substrate is lithographically processed, and the lithography quality is monitored in real time during the lithography process, and a feedback mechanism is established.

[0014] Preferably, preparing and testing the lithography equipment in S1 includes:

[0015] Lithography equipment includes lithography machines, light sources, masks, photoresists, glue coaters, baking ovens, and measurement and testing equipment;

[0016] Before the IC chip quartz substrate is photolithographically processed, the photolithography equipment is tested separately;

[0017] The lithography machine is subjected to exposure test, mechanical property test, calibration and alignment test; the light source is subjected to output and wavelength test; the mask is subjected to defect inspection and pattern accuracy test; the photoresist is subjected to uniformity and performance test; the glue coater is subjected to glue coating uniformity and development uniformity test; the baking furnace is subjected to temperature uniformity test; the measuring and testing equipment is subjected to accuracy verification and function test;

[0018] After all lithography equipment has passed the inspection, the inspection process is completed.

[0019] Preferably, the optical optimization adjustment is performed according to the device characteristics in S2, including:

[0020] Optically optimize the photolithography machine, light source and photoresist in the photolithography equipment;

[0021] The steps for optical optimization of lithography machines are as follows:

[0022] S211: Selecting a model of a lithography machine, wherein the model of the lithography machine is selected according to the IC chip;

[0023] Among them, when the IC chip is at a process node of 22nm or above, a 193nm lithography machine is selected; when the IC chip is at an advanced process node of 7nm or below, an EUV lithography machine is selected;

[0024] S212: Optimize the numerical aperture of the projection lens of the lithography machine according to the model of the lithography machine, wherein the numerical aperture of the 193nm lithography machine is 0.9-1.25; the numerical aperture of the EUV lithography machine is 0.25-0.33.

[0025] Preferably, the optical optimization adjustment according to the device characteristics in S2 further includes:

[0026] The steps for light source optical optimization are as follows:

[0027] S221: After the numerical aperture optimization of the lithography machine is completed, the wavelength of the 193nm lithography machine and the EUV lithography machine are adjusted respectively;

[0028] Among them, the 193nm lithography machine is a deep ultraviolet light source with a wavelength of 193 nanometers; the EUV lithography machine is an extreme ultraviolet light source with a wavelength of 13.5 nanometers;

[0029] S222: After the wavelength adjustment of the lithography machine is completed, the illumination mode of the 193nm lithography machine is selected according to the lithography pattern. The illumination modes are divided into conventional illumination, off-axis illumination and polarized illumination;

[0030] The reflective mirror of the EUV lithography machine was confirmed to have a reflectivity of >60% and a surface accuracy of <0.1 nm.

[0031] Preferably, the optical optimization adjustment according to the device characteristics in S2 further includes:

[0032] The steps for photoresist optical optimization are as follows

[0033] S231: Selecting a corresponding photoresist according to the model of the photolithography machine, wherein the photoresist corresponding to the 193nm photolithography machine is a chemically amplified photoresist, the photosensitizer in the chemically amplified photoresist is a sulfur heterocyclic compound, and the concentration of the sulfur heterocyclic compound is 1%-5%;

[0034] The photoresist corresponding to the EUV lithography machine is a water-based photoresist. The photosensitizer in the water-based photoresist is a photoacid generator, and the concentration of the photoacid generator is 1%-10%;

[0035] S232: setting the performance parameters of the photoresist, wherein the sensitivity of the chemically amplified photoresist is 1-10 mJ / cm²; the resolution is 40-100 nanometers; the contrast is 1.5-3; and the thermal stability is 200-400°C;

[0036] The sensitivity of water-based photoresist is 10-50 mJ / cm²; the resolution is <20nm; the contrast ratio is 2-3; and the thermal stability is 100-200℃.

[0037] Preferably, performing mask design for the lithography equipment that has been adjusted in S3 includes:

[0038] The mask design steps for 193nm lithography machine and EUV lithography machine are as follows:

[0039] S311: Obtain optical models of a 193nm lithography machine and an EUV lithography machine from a database, respectively, and establish an OPC model according to different optical models and photoresists, wherein the OPC model includes adding sub-resolution auxiliary features, and the sub-resolution auxiliary features include scattering strips and lenses;

[0040] S312: using the PSM technology to perform phase shift pattern design on the photolithography pattern, and using the PSM technology to perform correction;

[0041] After the calibration is completed, the phase shift pattern design is carried out, including the following steps:

[0042] S3121: Add auxiliary graphics to the designed phase shift pattern;

[0043] S3122: confirming the position and size of the phase shift region in the designed phase shift pattern, wherein the phase shift region is adjacent to the key pattern in the photolithography pattern;

[0044] S3123: setting the phase shift value in the phase shift region to 180°, thereby completing the design of the phase shift pattern;

[0045] S313: Integrate the designed phase-shift pattern into the OPC model, and perform simulation verification on the integrated OPC model, where the simulation verification includes exposure simulation, pattern analysis, and OPC parameter adjustment;

[0046] S314: After simulation verification, masks for 193nm lithography machine and EUV lithography machine are obtained.

[0047] Preferably, after the mask design in S4 is completed, the lithography equipment is temperature controlled, including:

[0048] The mask of the 193nm lithography machine is subjected to environmental temperature control. The steps are as follows:

[0049] S4011: storing the mask in a constant temperature and humidity environment, wherein the temperature is 15° C.-25° C. and the humidity is 40%-60%;

[0050] S4012: Mask the storage space as a clean room or a high-cleanliness storage cabinet.

[0051] Preferably, after the mask design in S4 is completed, the temperature of the lithography equipment is controlled, and the process further includes:

[0052] The mask of the EUV lithography machine is subjected to environmental temperature control. The steps are as follows:

[0053] S4021: Store the mask in an environment with a temperature of 2°C to 8°C and a humidity of less than 10%;

[0054] S4022: Mask the storage space as a clean room or storage cabinet with extremely high cleanliness.

[0055] Preferably, real-time monitoring of the lithography quality during the lithography process in S5 and establishing a feedback mechanism include:

[0056] When the 193nm lithography machine and EUV lithography machine perform lithography on the mask, the lithography process is monitored in real time. The real-time monitoring process is as follows:

[0057] S511: Optical microscope monitoring: Use an optical microscope to monitor the changes on the surface of the lithography machine and generate a monitoring report;

[0058] Optical projector monitoring: Use a projector to observe the pattern on the photoresist and generate a monitoring report;

[0059] S512: Fourier transform infrared spectroscopy analysis: Analyze the photochemical reaction of photoresist through FTIR and generate an analysis report;

[0060] Photoluminescence analysis: Use PL analysis to monitor the photochemical changes of photoresist during exposure and generate analysis reports;

[0061] S513: Electron beam inspection: Use EBIC to inspect the pattern on the photoresist and generate an inspection report:

[0062] S514: Mask contrast detection: Evaluate the contrast of the mask through a contrast detector and generate a detection report.

[0063] Preferably, real-time monitoring of the lithography quality during the lithography process in S5 and establishing a feedback mechanism also include:

[0064] Confirm the real-time monitoring data and divide the real-time monitoring data into text data and image data;

[0065] Conduct statistical analysis on text data and evaluation analysis on image data;

[0066] Retrieving process parameters based on the analysis results of text data and image data, the process parameters include exposure parameters, mask parameters, photoresist parameters, equipment parameters and process parameters;

[0067] Determine whether process parameters need to be adjusted based on the photolithography effect of the IC chip quartz substrate.

[0068] Compared with the prior art, the present invention has the following beneficial effects:

[0069] 1. The present invention provides an IC chip quartz substrate lithography process for reducing lithography distortion. By selecting a suitable lithography machine and optimizing its numerical aperture, the projection mode of light on the photoresist can be effectively controlled to reduce pattern distortion caused by light scattering, diffraction, etc., and by adjusting the wavelengths of the 193nm deep ultraviolet lithography machine and the EUV lithography machine respectively, it is ensured that each lithography machine can operate at its optimal working wavelength. By selecting a suitable photoresist and finely setting its performance parameters, the distortion in the lithography process can be effectively reduced.

[0070] 2. The present invention provides an IC chip quartz substrate lithography process for reducing lithography distortion. The PSM technology is used to perform phase shift design on the lithography pattern, which can further enhance the contrast of the lithography pattern, reduce the halo effect in the lithography process, make the edge of the pattern clearer and sharper, and help achieve a smaller line width and a higher pattern density. In the phase-shift pattern design, the lithography effect can be further optimized by adding auxiliary graphics, accurately controlling the position and size of the phase shift area, and setting a reasonable phase shift value.

[0071] 3. The present invention provides an IC chip quartz substrate lithography process that reduces lithography distortion. Accurate environmental temperature control is one of the key factors to ensure lithography quality. By reducing lithography distortion and improving mask stability, the manufacturing yield of IC chips can be significantly improved. According to the analysis results of monitoring data, exposure parameters, mask parameters, photoresist parameters, equipment parameters and process parameters can be accurately adjusted. This precise adjustment helps to reduce lithography distortion and improve chip manufacturing quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 It is a schematic diagram of the IC chip quartz substrate photolithography process steps of the present invention;

[0073] Figure 2 It is a schematic diagram of the IC chip quartz substrate photolithography process flow of the present invention;

[0074] Figure 3 A schematic diagram of the mask design steps for a photolithography machine of the present invention;

[0075] Figure 4 It is a schematic diagram of the phase shift pattern design steps in the mask design of the present invention. DETAILED DESCRIPTION

[0076] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 are within the scope of protection of the present invention.

[0077] In order to solve the problem that the existing technology does not perform targeted equipment optical optimization according to the different distortion performance of each lithography equipment, which leads to the extension of lithography process cycle and the reduction of lithography accuracy, please refer to Figure 1-Figure 4 , this embodiment provides the following technical solutions:

[0078] An IC chip quartz substrate photolithography process for reducing photolithography distortion comprises the following steps:

[0079] S1: Quartz substrate lithography equipment confirmation: Before the IC chip quartz substrate is lithographically processed, the lithography equipment must be prepared and tested;

[0080] Among them, through strict testing and calibration, rework and waste caused by photolithography distortion or defects are reduced;

[0081] S2: Optical optimization of lithography equipment: Optical optimization and adjustment of the inspected lithography equipment according to the equipment characteristics;

[0082] Among them, suitable photolithography machines and optimized optical parameters can shorten the time of photolithography process and improve production efficiency. Selecting appropriate illumination modes according to different photolithography patterns can effectively control the light intensity distribution and improve the contrast of photolithography patterns. By optimizing the selection and performance parameters of photoresist, the circuit pattern on the chip can be ensured to be accurate.

[0083] S3: Photolithography mask design: After the photolithography equipment is optically optimized and adjusted, the adjusted photolithography equipment is used for mask design;

[0084] Among them, comprehensive simulation verification such as exposure simulation, pattern analysis and OPC parameter adjustment can ensure the rationality and reliability of mask design;

[0085] S4: Environmental temperature control: After the mask design is completed, the lithography equipment is temperature controlled;

[0086] Among them, precise environmental temperature control effectively reduces photolithography distortion and improves mask stability, which can significantly improve the manufacturing yield of IC chips;

[0087] S5: Quartz substrate lithography monitoring: After temperature control, the IC chip quartz substrate is lithographically processed, and the lithography quality is monitored in real time during the lithography process, and a feedback mechanism is established;

[0088] Among them, by real-time monitoring of lithography quality, various variables in the lithography process can be accurately controlled and lithography errors caused by process fluctuations can be reduced.

[0089] Prepare and inspect the lithography equipment in S1, including:

[0090] Lithography equipment includes lithography machines, light sources, masks, photoresists, glue coaters, baking ovens, and measurement and testing equipment;

[0091] Before the IC chip quartz substrate is photolithographically processed, the photolithography equipment is tested separately;

[0092] The lithography machine is subjected to exposure test, mechanical property test, calibration and alignment test; the light source is subjected to output and wavelength test; the mask is subjected to defect inspection and pattern accuracy test; the photoresist is subjected to uniformity and performance test; the glue coater is subjected to glue coating uniformity and development uniformity test; the baking furnace is subjected to temperature uniformity test; the measuring and testing equipment is subjected to accuracy verification and function test;

[0093] After all lithography equipment has passed the inspection, the inspection process is completed.

[0094] Specifically, by performing exposure tests, mechanical property, calibration and alignment tests on the lithography machine, the exposure accuracy, alignment accuracy and stability of mechanical movement during the lithography process can be ensured, thereby reducing the offset or deformation of the lithography pattern caused by equipment factors. The defect inspection and pattern accuracy detection of the mask can identify and eliminate any factors that may affect the pattern transfer accuracy, such as dust, scratches or pattern distortion, thereby improving the accuracy of the lithography pattern. The output and wavelength detection of the light source ensure the stability and consistency of the light source during the exposure process, avoiding inconsistent lithography results due to light source fluctuations. The uniformity and performance testing of the photoresist can ensure that the photoresist layer coated on the substrate has consistent performance, reducing lithography problems caused by uneven photoresist. The coating uniformity and development uniformity detection of the coater, as well as the temperature uniformity detection of the baking oven, together ensure the uniform treatment of the photoresist layer on the entire substrate, improve the stability of the process, and through strict testing and calibration, reduce rework and waste caused by lithography distortion or defects, saving time and cost.

[0095] Optical optimization and adjustment are performed in S2 according to the characteristics of the device, including:

[0096] Optically optimize the photolithography machine, light source and photoresist in the photolithography equipment;

[0097] The steps for optical optimization of lithography machines are as follows:

[0098] S211: Selecting a model of a lithography machine, wherein the model of the lithography machine is selected according to the IC chip;

[0099] Among them, when the IC chip is at a process node of 22nm or above, a 193nm lithography machine is selected; when the IC chip is at an advanced process node of 7nm or below, an EUV lithography machine is selected;

[0100] S212: Optimize the numerical aperture of the projection lens of the lithography machine according to the model of the lithography machine, wherein the numerical aperture of the 193nm lithography machine is 0.9-1.25; the numerical aperture of the EUV lithography machine is 0.25-0.33.

[0101] Specifically, by selecting the appropriate lithography machine model according to the process node of the IC chip (such as selecting a 193nm lithography machine for a process node of 22nm or above, and selecting an EUV lithography machine for an advanced process node of 7nm or below), it is possible to ensure that the lithography process is highly matched with the chip manufacturing requirements. The numerical aperture optimization for different types of lithography machines (such as the numerical aperture of a 193nm lithography machine is 0.9-1.25, and the numerical aperture of an EUV lithography machine is 0.25-0.33) further improves the light focusing accuracy during the lithography process, thereby reducing the geometric distortion and diffraction effect during the lithography process, and improving the edge clarity and accuracy of the graphics. One of the direct goals of optical optimization adjustment is to reduce distortion during the lithography process. By selecting a suitable lithography machine and optimizing its numerical aperture, the projection method of light on the photoresist can be effectively controlled, reducing the distortion of graphics caused by light scattering, diffraction, etc., and the suitable lithography machine and optimized optical parameters can shorten the lithography process time and improve production efficiency.

[0102] The steps for light source optical optimization are as follows:

[0103] S221: After the numerical aperture optimization of the lithography machine is completed, the wavelength of the 193nm lithography machine and the EUV lithography machine are adjusted respectively;

[0104] Among them, the 193nm lithography machine is a deep ultraviolet light source with a wavelength of 193 nanometers; the EUV lithography machine is an extreme ultraviolet light source with a wavelength of 13.5 nanometers;

[0105] S222: After the wavelength adjustment of the lithography machine is completed, the illumination mode of the 193nm lithography machine is selected according to the lithography pattern. The illumination modes are divided into conventional illumination, off-axis illumination and polarized illumination;

[0106] The reflective mirror of the EUV lithography machine was confirmed to have a reflectivity of >60% and a surface accuracy of <0.1 nm.

[0107] Specifically, by adjusting the wavelength of the 193nm deep ultraviolet lithography machine and the EUV (extreme ultraviolet) lithography machine respectively, it is ensured that each lithography machine can operate at its optimal operating wavelength. This helps to improve the resolution and accuracy of the lithography process. Short wavelengths (such as EUV's 13.5 nanometers) can significantly reduce the diffraction effect of light, making the edges of the lithography pattern sharper, thereby reducing distortion. Different IC designs may require different lithography wavelengths to achieve the best pattern resolution and depth. Wavelength adjustment enables the lithography machine to flexibly respond to different process requirements. EUV lithography machines represent the forefront of lithography technology. Their extremely short wavelength is the key to achieving smaller line widths and higher integration. As a deep ultraviolet light source, the 193nm lithography machine complements the EUV lithography machine and is suitable for manufacturing needs at different stages to jointly improve the overall lithography effect. Selecting the appropriate illumination mode according to different lithography patterns can effectively control the light intensity distribution and improve the contrast of the lithography pattern. In particular, off-axis illumination and polarized illumination modes can effectively reduce the non-uniform reflection and scattering of light on the quartz substrate, further reducing lithography distortion. The reflectivity of the reflector is greater than 60%, ensuring the efficient use of light energy, reducing energy loss, and improving lithography efficiency. Mirrors with a surface accuracy of less than 0.1nm can greatly reduce the deformation and distortion of light during the reflection process, ensuring the accuracy of the lithography pattern. From light source selection, wavelength adjustment to illumination mode optimization, and then to the use of high-performance reflectors, each step is aimed at reducing distortion in the lithography process and improving the fidelity of the pattern.

[0108] The steps for photoresist optical optimization are as follows:

[0109] S231: Selecting a corresponding photoresist according to the model of the photolithography machine, wherein the photoresist corresponding to the 193nm photolithography machine is a chemically amplified photoresist, the photosensitizer in the chemically amplified photoresist is a sulfur heterocyclic compound, and the concentration of the sulfur heterocyclic compound is 1%-5%;

[0110] The photoresist corresponding to the EUV lithography machine is a water-based photoresist. The photosensitizer in the water-based photoresist is a photoacid generator, and the concentration of the photoacid generator is 1%-10%;

[0111] S232: setting the performance parameters of the photoresist, wherein the sensitivity of the chemically amplified photoresist is 1-10 mJ / cm²; the resolution is 40-100 nanometers; the contrast is 1.5-3; and the thermal stability is 200-400°C;

[0112] The sensitivity of water-based photoresist is 10-50 mJ / cm²; the resolution is <20nm; the contrast ratio is 2-3; and the thermal stability is 100-200℃.

[0113] Specifically, the corresponding photoresist is selected according to the model of the lithography machine (such as 193nm lithography machine and EUV lithography machine). This precise matching ensures that the chemical and physical reactions in the lithography process can be optimized and reduces the lithography distortion caused by mismatch. For 193nm lithography machines, chemically amplified photoresists are selected, and their sulfur heterocyclic compounds are used as photosensitizers, which can be highly sensitive to light at specific wavelengths; for EUV lithography machines, water-based photoresists and photoacid generators are selected to adapt to the high energy characteristics of EUV light, and the key performance parameters of the photoresist are set in detail, including sensitivity, resolution, contrast and thermal stability. The fine control of these parameters is crucial to improving the accuracy and stability of lithography. Among them, the high sensitivity and high resolution of chemically amplified photoresists are suitable for the formation of fine patterns, and their good thermal stability ensures the stability of patterns during high-temperature processing; although water-based photoresists have lower sensitivity, their extremely high resolution (<20nm) is very suitable for EUV lithography processes, and appropriate contrast and thermal stability also ensure the quality of lithography. By selecting suitable photoresists and finely setting their performance parameters, distortion in the lithography process can be effectively reduced. This includes the edge roughness of the pattern, the change in line width, and the offset of the pattern position. Fine photoresist selection and performance parameter setting make the lithography process more controllable, improve the consistency and yield of IC chip manufacturing, and reduce lithography distortion directly improve the quality of IC chips. High-precision lithography on quartz substrates is one of the key steps in manufacturing advanced IC chips. By optimizing the selection and performance parameters of photoresists, the circuit pattern on the chip can be ensured to be accurate, thereby improving the performance and reliability of the chip.

[0114] In order to solve the problem that in the prior art, different mask designs are not performed according to the differences in lithography equipment, resulting in the inability to perform lithography patterns more accurately, please refer to Figure 1-Figure 4 , this embodiment provides the following technical solutions:

[0115] Perform mask design for the lithography equipment that will be adjusted in S3, including:

[0116] The mask design steps for 193nm lithography machine and EUV lithography machine are as follows:

[0117] S311: Obtain optical models of a 193nm lithography machine and an EUV lithography machine from a database, respectively, and establish an OPC model according to different optical models and photoresists, wherein the OPC model includes adding sub-resolution auxiliary features, and the sub-resolution auxiliary features include scattering strips and lenses;

[0118] S312: using the PSM technology to perform phase shift pattern design on the photolithography pattern, and using the PSM technology to perform correction;

[0119] After the calibration is completed, the phase shift pattern design is carried out, including the following steps:

[0120] S3121: Add auxiliary graphics to the designed phase shift pattern;

[0121] S3122: confirming the position and size of the phase shift region in the designed phase shift pattern, wherein the phase shift region is adjacent to the key pattern in the photolithography pattern;

[0122] S3123: setting the phase shift value in the phase shift region to 180°, thereby completing the design of the phase shift pattern;

[0123] S313: Integrate the designed phase-shift pattern into the OPC model, and perform simulation verification on the integrated OPC model, where the simulation verification includes exposure simulation, pattern analysis, and OPC parameter adjustment;

[0124] S314: After simulation verification, masks for 193nm lithography machine and EUV lithography machine are obtained.

[0125] Specifically, by establishing an accurate OPC (optical proximity correction) model and adding sub-resolution auxiliary features (such as scattering strips and lenses), the distortion of the lithography pattern caused by the diffraction and interference effects of light can be effectively compensated, thereby improving the accuracy and resolution of lithography. By using PSM (phase shift mask) technology and performing phase shift design on the lithography pattern, the contrast of the lithography pattern can be further enhanced, the halo effect in the lithography process can be reduced, and the edge of the pattern can be clearer and sharper, which helps to achieve smaller line width and higher pattern density. In the phase shift pattern design, by adding auxiliary graphics, accurately controlling the position and size of the phase shift area, and setting a reasonable phase shift value (such as 180°), the lithography effect can be further optimized and the pattern distortion caused by process fluctuations can be reduced. After the designed phase shift pattern is integrated into the OPC model, comprehensive simulation verification such as exposure simulation, pattern analysis and OPC parameter adjustment can be performed to ensure the rationality and reliability of the mask design. This "simulation before manufacturing" approach can significantly reduce the cost of trial and error, improve production efficiency and yield rate, and take into account the mask design of 193nm lithography machines and EUV (extreme ultraviolet) lithography machines, showing good flexibility and adaptability. This is of great significance for meeting the needs of different manufacturing processes and achieving process upgrades and conversions.

[0126] In order to solve the problem in the prior art that the designed mask is not saved according to the characteristics after being designed, and when the IC chip quartz substrate is photolithographic, the photolithography process is not monitored in real time, resulting in the inability to obtain more accurate photolithography process parameters, please refer to Figure 1-Figure 4 , this embodiment provides the following technical solutions:

[0127] After the mask design in S4 is completed, the temperature of the lithography equipment is controlled, including:

[0128] The mask of the 193nm lithography machine is subjected to environmental temperature control. The steps are as follows:

[0129] S4011: storing the mask in a constant temperature and humidity environment, wherein the temperature is 15° C.-25° C. and the humidity is 40%-60%;

[0130] S4012: Mask the storage space as a clean room or a high-cleanliness storage cabinet.

[0131] The mask of the EUV lithography machine is subjected to environmental temperature control. The steps are as follows:

[0132] S4021: Store the mask in an environment with a temperature of 2°C to 8°C and a humidity of less than 10%;

[0133] S4022: Mask the storage space as a clean room or storage cabinet with extremely high cleanliness.

[0134] Specifically, for 193nm lithography machines, storing masks in a constant temperature and humidity environment with a temperature of 15℃-25℃ and a humidity of 40%-60% can effectively reduce the thermal expansion and contraction of mask materials caused by temperature fluctuations. This temperature variation range is relatively small, which is conducive to maintaining the stability of mask dimensions, thereby reducing dimensional distortion during the lithography process. For EUV lithography machines, their masks are more sensitive to temperature changes. Therefore, setting the storage temperature to a lower 2℃-8℃ and controlling the humidity below 10% further reduces the risk of thermal expansion and contraction, ensuring the accuracy of the mask in high-precision lithography. Whether it is a 193nm lithography machine or an EUV lithography machine, its mask storage space is required to be a clean room or a high / extremely high cleanliness storage cabinet. This requirement is intended to prevent contaminants such as dust and particles from adhering to the mask, which may cause pattern defects or distortion during the lithography process. A high-cleanliness environment is essential to ensure the quality of lithography, and precise environmental temperature control is one of the key factors to ensure the quality of lithography. By reducing lithography distortion and improving mask stability, the manufacturing yield of IC chips can be significantly improved, thereby improving the overall product quality.

[0135] Real-time monitoring of lithography quality during the lithography process in S5 and establishment of a feedback mechanism, including:

[0136] When the 193nm lithography machine and EUV lithography machine perform lithography on the mask, the lithography process is monitored in real time. The real-time monitoring process is as follows:

[0137] S511: Optical microscope monitoring: Use an optical microscope to monitor the changes on the surface of the lithography machine and generate a monitoring report;

[0138] Optical projector monitoring: Use a projector to observe the pattern on the photoresist and generate a monitoring report;

[0139] S512: Fourier transform infrared spectroscopy analysis: Analyze the photochemical reaction of photoresist through FTIR and generate an analysis report;

[0140] Photoluminescence analysis: Use PL analysis to monitor the photochemical changes of photoresist during exposure and generate analysis reports;

[0141] S513: Electron beam inspection: Use EBIC to inspect the pattern on the photoresist and generate an inspection report:

[0142] S514: Mask contrast detection: Evaluate the contrast of the mask through a contrast detector and generate a detection report.

[0143] Specifically, the optical microscope can capture tiny changes on the surface, while the optical projector can accurately observe the pattern details on the photoresist. This dual monitoring ensures the visualization accuracy of the lithography process and helps to find problems in time. FTIR can analyze the chemical structure changes of the photoresist, while PL reveals the kinetic process of the photochemical reaction. These analyses help to understand the performance changes of the photoresist and optimize the lithography conditions. The EBIC technology directly detects the pattern on the photoresist through the electron beam and provides high-resolution image data. This method is particularly effective in detecting tiny structural changes and helps to accurately evaluate the lithography effect. The contrast detector can evaluate the contrast of the mask to ensure that the quality of the mask meets the lithography requirements. High-contrast masks help reduce distortion in the lithography process and improve imaging quality. According to the analysis results of the monitoring data, the exposure parameters, mask parameters, photoresist parameters, equipment parameters and process parameters can be accurately adjusted. This precise adjustment helps to reduce lithography distortion and improve the manufacturing quality of chips. Through the above-mentioned monitoring methods, various variables in the lithography process can be accurately controlled to reduce lithography errors caused by process fluctuations. This helps improve the accuracy of photolithography, making chip manufacturing more sophisticated, and by reducing photolithography distortion and process adjustment times, it can reduce manufacturing costs caused by scrap and repeated processing. In addition, precise control of process parameters can also help improve material utilization and further reduce production costs.

[0144] Confirm the real-time monitoring data and divide the real-time monitoring data into text data and image data;

[0145] Conduct statistical analysis on text data and evaluation analysis on image data;

[0146] Retrieving process parameters based on the analysis results of text data and image data, the process parameters include exposure parameters, mask parameters, photoresist parameters, equipment parameters and process parameters;

[0147] Determine whether process parameters need to be adjusted based on the photolithography effect of the IC chip quartz substrate.

[0148] Specifically, through statistical analysis and evaluation analysis of text data and image data, the status of the lithography process can be fully understood from different angles. This multi-dimensional data analysis method helps to identify the root cause of the problem more accurately. According to the analysis results of the monitoring data, the process parameters (such as exposure parameters, mask parameters, photoresist parameters, equipment parameters and process parameters) can be accurately adjusted. This refined adjustment method helps to reduce distortion in the lithography process and improve the manufacturing quality of chips. The combination of real-time monitoring and precise adjustment can significantly improve the accuracy and stability of lithography. By continuously optimizing process parameters, lithography errors caused by process fluctuations can be reduced.

[0149] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0150] While the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that many changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the invention.

Claims

1. A quartz substrate photolithography process for IC chips with reduced photolithography distortion, characterized in that: The steps include: S1: Quartz substrate lithography equipment confirmation: Before the IC chip quartz substrate is lithographically processed, the lithography equipment must be prepared and tested; S2: Optical optimization of lithography equipment: Optical optimization and adjustment of the inspected lithography equipment according to the equipment characteristics; S3: Photolithography mask design: After the photolithography equipment is optically optimized and adjusted, the adjusted photolithography equipment is used for mask design; S4: Environmental temperature control: After the mask design is completed, the lithography equipment is temperature controlled; S5: Quartz substrate lithography monitoring: After temperature control, the IC chip quartz substrate is lithographically processed, and the lithography quality is monitored in real time during the lithography process, and a feedback mechanism is established; Optical optimization and adjustment are performed in S2 according to the characteristics of the device, including: Optically optimize the photolithography machine, light source and photoresist in the photolithography equipment; The steps for optical optimization of lithography machines are as follows: S211: Selecting a model of a lithography machine, wherein the model of the lithography machine is selected according to the IC chip; Among them, when the IC chip is at a process node of 22nm or above, a 193nm lithography machine is selected; when the IC chip is at an advanced process node of 7nm or below, an EUV lithography machine is selected; S212: Optimizing the numerical aperture of the projection lens of the lithography machine according to the model of the lithography machine, wherein the numerical aperture of the 193nm lithography machine is 0.9-1.25; the numerical aperture of the EUV lithography machine is 0.25-0.33; The steps for light source optical optimization are as follows: S221: After the numerical aperture optimization of the lithography machine is completed, the wavelength of the 193nm lithography machine and the EUV lithography machine are adjusted respectively; Among them, the 193nm lithography machine is a deep ultraviolet light source with a wavelength of 193 nanometers; the EUV lithography machine is an extreme ultraviolet light source with a wavelength of 13.5 nanometers; S222: After the wavelength adjustment of the lithography machine is completed, the illumination mode of the 193nm lithography machine is selected according to the lithography pattern. The illumination modes are divided into conventional illumination, off-axis illumination and polarized illumination; Confirm the reflector of EUV lithography machine, the reflectivity of the reflector is greater than 60%, and the surface accuracy is less than 0.1nm; The steps for photoresist optical optimization are as follows: S231: Selecting a corresponding photoresist according to the model of the photolithography machine, wherein the photoresist corresponding to the 193nm photolithography machine is a chemically amplified photoresist, the photosensitizer in the chemically amplified photoresist is a sulfur heterocyclic compound, and the concentration of the sulfur heterocyclic compound is 1%-5%; The photoresist corresponding to the EUV lithography machine is a water-based photoresist. The photosensitizer in the water-based photoresist is a photoacid generator, and the concentration of the photoacid generator is 1%-10%; S232: setting the performance parameters of the photoresist, wherein the sensitivity of the chemically amplified photoresist is 1-10 mJ / cm²; the resolution is 40-100 nanometers; the contrast is 1.5-3; and the thermal stability is 200-400°C; The sensitivity of water-based photoresist is 10-50 mJ / cm²; the resolution is <20nm; the contrast ratio is 2-3; and the thermal stability is 100-200℃.

2. The IC chip quartz substrate photolithography process for reducing photolithography distortion according to claim 1, characterized in that: Prepare and inspect the lithography equipment in S1, including: Lithography equipment includes lithography machines, light sources, masks, photoresists, glue coaters, baking ovens, and measurement and testing equipment; Before the IC chip quartz substrate is photolithographically processed, the photolithography equipment is tested separately; The lithography machine is subjected to exposure test, mechanical property test, calibration and alignment test; the light source is subjected to output and wavelength test; the mask is subjected to defect inspection and pattern accuracy test; the photoresist is subjected to uniformity and performance test; the glue coater is subjected to glue coating uniformity and development uniformity test; the baking furnace is subjected to temperature uniformity test; the measuring and testing equipment is subjected to accuracy verification and function test; After all lithography equipment has passed the inspection, the inspection process is completed.

3. The IC chip quartz substrate photolithography process for reducing photolithography distortion according to claim 2, characterized in that: Perform mask design for the lithography equipment that will be adjusted in S3, including: The mask design steps for 193nm lithography machine and EUV lithography machine are as follows: S311: Obtain optical models of a 193nm lithography machine and an EUV lithography machine from a database, respectively, and establish an OPC model according to different optical models and photoresists, wherein the OPC model includes adding sub-resolution auxiliary features, and the sub-resolution auxiliary features include scattering strips and lenses; S312: using the PSM technology to perform phase shift pattern design on the photolithography pattern, and using the PSM technology to perform correction; After the calibration is completed, the phase shift pattern design is carried out, including the following steps: S3121: Add auxiliary graphics to the designed phase shift pattern; S3122: confirming the position and size of the phase shift region in the designed phase shift pattern, wherein the phase shift region is adjacent to the key pattern in the photolithography pattern; S3123: setting the phase shift value in the phase shift region to 180°, thereby completing the design of the phase shift pattern; S313: Integrate the designed phase-shift pattern into the OPC model, and perform simulation verification on the integrated OPC model, where the simulation verification includes exposure simulation, pattern analysis, and OPC parameter adjustment; S314: After simulation verification, masks for 193nm lithography machine and EUV lithography machine are obtained.

4. The IC chip quartz substrate photolithography process for reducing photolithography distortion according to claim 3, characterized in that: After the mask design in S4 is completed, the temperature of the lithography equipment is controlled, including: The mask of the 193nm lithography machine is subjected to environmental temperature control. The steps are as follows: S4011: storing the mask in a constant temperature and humidity environment, wherein the temperature is 15° C.-25° C. and the humidity is 40%-60%; S4012: Mask the storage space as a clean room or a high-cleanliness storage cabinet.

5. The IC chip quartz substrate photolithography process for reducing photolithography distortion according to claim 4, characterized in that: After the mask design in S4 is completed, the temperature of the lithography equipment is controlled, which also includes: The mask of the EUV lithography machine is subjected to environmental temperature control. The steps are as follows: S4021: Store the mask in an environment with a temperature of 2°C to 8°C and a humidity of less than 10%; S4022: Mask the storage space as a clean room or storage cabinet with extremely high cleanliness.

6. The IC chip quartz substrate photolithography process for reducing photolithography distortion according to claim 5, characterized in that: Real-time monitoring of lithography quality during the lithography process in S5 and establishment of a feedback mechanism, including: When the 193nm lithography machine and EUV lithography machine perform lithography on the mask, the lithography process is monitored in real time. The real-time monitoring process is as follows: S511: Optical microscope monitoring: Use an optical microscope to monitor the changes on the surface of the lithography machine and generate a monitoring report; Optical projector monitoring: Use a projector to observe the pattern on the photoresist and generate a monitoring report; S512: Fourier transform infrared spectroscopy analysis: Analyze the photochemical reaction of photoresist through FTIR and generate an analysis report; Photoluminescence analysis: Use PL analysis to monitor the photochemical changes of photoresist during exposure and generate analysis reports; S513: Electron beam inspection: Use EBIC to inspect the pattern on the photoresist and generate an inspection report: S514: Mask contrast detection: Evaluate the contrast of the mask through a contrast detector and generate a detection report.

7. The IC chip quartz substrate photolithography process for reducing photolithography distortion according to claim 6, characterized in that: Real-time monitoring of lithography quality during the lithography process in S5 and establishment of a feedback mechanism also include: Confirm the real-time monitoring data and divide the real-time monitoring data into text data and image data; Conduct statistical analysis on text data and evaluation analysis on image data; Retrieving process parameters based on the analysis results of text data and image data, the process parameters include exposure parameters, mask parameters, photoresist parameters, equipment parameters and process parameters; Determine whether process parameters need to be adjusted based on the photolithography effect of the IC chip quartz substrate.

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