Real-time process control system and control method

Abstract

The invention discloses a real-time process control system and method, and the system comprises a data obtaining module which is used for obtaining the process collection parameters of a target process in real time at a target interval moment in the process flow of semiconductor photoetching process equipment for semiconductors, and the process flow of the semiconductors is used for representing the process cycle of a single semiconductor; the photoetching analysis module is used for receiving the process acquisition parameters transmitted by the data acquisition module and then performing data analysis on the process acquisition parameters so as to obtain process adjustment parameters and then feed back the process adjustment parameters to the semiconductor photoetching process equipment; and after the semiconductor photoetching process equipment receives the fed back process adjustment parameters, the process acquisition parameters at the target moment are updated. Real-time monitoring and parameter adjustment feedback of the manufacturing process can be achieved in the manufacturing process of the single semiconductor, compared with batch adjustment in the prior art, the convergence degree is higher, the product quality problem caused by parameter deviation can be reduced, and the production efficiency and the product quality are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor photolithography manufacturing, and in particular relates to a real-time process control system and a control method. Background Art

[0002] In semiconductor manufacturing, advanced process control (APC) has important applications in the photolithography process, aiming to improve process stability, reduce line width variation, improve graphic accuracy, and thus improve process yield. As one of the key steps in manufacturing tiny structures, the photolithography process requires extremely high precision control of mask alignment, exposure, and development, so APC technology has played a significant role in this field.

[0003] Existing photolithography systems generally use a non-real-time method to perform advanced process control (APC), and its application in yellow light processes is as follows.

[0004] 1. Mask alignment control

[0005] 1.1. Use the feedback and feedforward control technology in APC to adjust the mask alignment to ensure the pattern alignment accuracy between layers. Especially in the case of multi-layer circuits, small alignment errors will affect device performance.

[0006] 1.2. The automatic alignment system will compensate according to the detected offset and feed back the adjustment results to the system in real time to achieve higher accuracy.

[0007] 2. Exposure control

[0008] 2.1. Precise control of exposure is crucial for line width consistency. The APC system adjusts the light dose according to the exposure results of each batch to prevent line width variation caused by overexposure or underexposure.

[0009] 2.2. Use real-time monitoring and model prediction technology to optimize exposure parameters, ensure uniform exposure, and improve image quality.

[0010] 3. Development control

[0011] 3.1、Parameters such as temperature, time, and chemical concentration during the development process will affect the final image quality. APC can monitor and adjust the development conditions in real time and dynamically optimize the development process based on previous batch data.

[0012] 3.2. In particular, the use of batch-to-batch control (R2R control) can make fine adjustments based on the previous results to ensure stable development effects.

[0013] 4. Thickness and uniformity control

[0014] 4.1. In the photolithography process, the thickness and uniformity of the photoresist directly affect the accuracy of pattern transfer. APC maintains the uniformity of the photoresist thickness by monitoring and adjusting the coating and baking parameters, further improving the stability of line width control.

[0015] 5. Line width control

[0016] 5.1. APC combines the line width detection system to measure the exposed graphics, and predicts and compensates for line width variation through a model-based control system. By adjusting parameters such as exposure, focal length, and development conditions in real time, the line width is kept within the target range.

[0017] 6. Fault Detection and Classification (FDC)

[0018] 6.1. Applying FDC in the photolithography process can detect and classify possible anomalies in the photolithography process in real time, such as mask degradation, exposure machine offset, photoresist contamination, etc. Such fault detection can prevent unqualified products from continuing to flow into subsequent processes, effectively improving the yield rate.

[0019] 7. Data Analysis and Machine Learning

[0020] 8. Applying data analysis and machine learning techniques to the data of the yellow light process can discover hidden correlations between parameters and further optimize the process control strategy. By analyzing historical data, the APC system can better predict and correct possible process deviations.

[0021] To achieve the above applications, advanced process control (APC) generally adopts a closed-loop architecture. For the control within the target process, the APC system monitors and controls the equipment and uses measurement equipment to detect the target process to adjust the process parameters to ensure product quality, reduce variation and improve yield. Figure 1 shown.

[0022] However, the common advanced process control (APC) technology currently is nothing more than adjusting process parameters by monitoring and controlling equipment and testing the target process through measurement equipment, so as to increase the output and reduce defects in the next batch of manufacturing to improve its yield. Figure 1 The loop architecture not only detects the current status of the machine, but also detects the results of the target process and adjusts its key process parameters. Although this method can adjust the parameters of the target process, it must adjust the process parameters based on the output of the batch, and cannot achieve real-time process control. Summary of the invention

[0023] In view of the deficiencies of the prior art, the present invention aims to provide a real-time process control system, which is used to realize process control of semiconductor lithography process equipment. The real-time process control system comprises:

[0024] A data acquisition module, used for acquiring process acquisition parameters of a target process in real time at a target interval in the semiconductor process flow of the semiconductor lithography process equipment, wherein the target process is at least one process in the semiconductor process flow, and the semiconductor process flow is used to characterize the process cycle of a single semiconductor;

[0025] A lithography analysis module, the lithography analysis module is in communication with the data acquisition module, the lithography analysis module is used to receive the process acquisition parameters transmitted by the data acquisition module, and perform data analysis on the process acquisition parameters to obtain process adjustment parameters, and then feed back the process adjustment parameters to the semiconductor lithography process equipment;

[0026] The semiconductor lithography process equipment is communicatively connected with the lithography analysis module. After receiving the process adjustment parameters fed back by the lithography analysis module, the semiconductor lithography process equipment is used to update the process acquisition parameters at a target moment based on the process adjustment parameters. The target moment is a moment before the target interval moment from the current moment, and the current moment is the moment when the semiconductor lithography process equipment receives the process adjustment parameters.

[0027] In some embodiments, the real-time process control system further includes a data storage module, and the data storage module is used to receive and update the process adjustment parameters fed back by the lithography analysis module.

[0028] In some embodiments, the lithography analysis module is constructed as a lithography analysis model, and the lithography analysis model is obtained by real-time iterative training based on the stored data in the database.

[0029] In some embodiments, the real-time process control system also includes an abnormality monitoring module, which is electrically connected to the semiconductor lithography process equipment. The abnormality monitoring module is used to monitor whether the process acquisition parameters acquired by the data acquisition module are abnormal, so as to respond when abnormal process acquisition parameters are determined.

[0030] In some embodiments, the real-time process control system also includes a compensation module, which is communicatively connected to the abnormal monitoring module and the data acquisition module. The compensation module is used to compensate for the abnormal process acquisition parameters after receiving a response signal from the abnormal monitoring module, and update the abnormal process acquisition parameters based on the compensated process compensation parameters.

[0031] According to another aspect of the present application, a real-time process control method is disclosed. The real-time process control method is implemented based on any of the above-mentioned real-time process control systems. The real-time process control method includes:

[0032] Controlling the data acquisition module to acquire process acquisition parameters of a target process in real time at a target interval in the semiconductor process flow of the semiconductor lithography process equipment, wherein the target process is at least one process in the semiconductor process flow, and the semiconductor process flow is used to characterize the process cycle of a single semiconductor;

[0033] Controlling the photolithography analysis module to receive the process acquisition parameters transmitted by the data acquisition module, and performing data analysis on the process acquisition parameters to obtain process adjustment parameters and then feeding back the process adjustment parameters to the semiconductor photolithography process equipment, wherein the photolithography analysis module is in communication connection with the data acquisition module;

[0034] After the semiconductor lithography process equipment receives the process adjustment parameters fed back by the lithography analysis module, the process acquisition parameters at the target moment are updated based on the process adjustment parameters, wherein the target moment is the moment before the target interval moment from the current moment, and the current moment is the moment when the semiconductor lithography process equipment receives the process adjustment parameters, and the semiconductor lithography process equipment is communicatively connected with the lithography analysis module.

[0035] In some embodiments, the method further includes constructing a lithography analysis model for use as a lithography analysis module, wherein constructing the lithography analysis model includes:

[0036] Acquire stored data in a database, wherein the stored data includes process parameters, equipment attribute parameters, and material attribute parameters, wherein the equipment attribute parameters are used to characterize attribute information of the semiconductor photolithography process equipment, and the material attribute parameters are used to characterize attribute information of the processed raw material wafers, wherein the process parameters are the process acquisition parameters before and after the update, and the process parameters include process parameters, environmental parameters, and process result parameters of the target process;

[0037] The process acquisition parameters, the equipment attribute parameters and the material attribute parameter data in the database are cleaned and then model training is performed to obtain the lithography analysis model.

[0038] In some embodiments, the method further comprises:

[0039] The control abnormality detection module monitors whether the process acquisition parameters acquired by the data acquisition module are abnormal, so as to respond when abnormal process acquisition parameters are determined.

[0040] In some embodiments, the method further comprises:

[0041] The control compensation module is used to compensate the abnormal process acquisition parameters after receiving the response signal of the abnormal monitoring module, and update the abnormal process acquisition parameters based on the compensated process compensation parameters:

[0042] The present invention includes but is not limited to the following beneficial effects: (1) The present invention can realize real-time monitoring and parameter adjustment feedback of the process during the process of single-chip semiconductor manufacturing. Compared with the batch adjustment in the prior art, the convergence degree is higher, which helps to reduce product quality problems caused by parameter deviation and improve production efficiency and product quality; (2) The present invention can more effectively manage and track the historical records of process adjustment parameters by storing the data at each moment, whether it is collected or adjusted, in the database, and can provide more comprehensive data for subsequent analysis and optimization, which is conducive to the transparency and traceability of the system; (3) The lithography analysis model in the present invention can be trained in real time based on the stored data in the database, so that the system can learn and optimize in real time according to the latest data, so as to better adapt to the changes in the process; (4) The present invention monitors whether the process acquisition parameters are abnormal through the abnormality monitoring module, which can effectively discover potential process problems before the problem occurs, realize timely maintenance and adjustment of the process, and improve production efficiency and product quality; (5) The present invention can compensate and adjust the abnormal process acquisition parameters when certain parameters are found to be abnormal through the compensation module, thereby reducing the impact of the abnormality on the process and ensuring the stability and accuracy of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0044] Figure 1 It is a closed-loop architecture diagram of advanced process control (APC) in the prior art;

[0045] Figure 2 is a schematic diagram of the overall structure of a real-time process control system according to an embodiment of the present invention;

[0046] Figure 3 is a schematic diagram of the principle of a real-time process control system according to an embodiment of the present invention;

[0047] Figure 4 is a flow chart of a process control method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The technical scheme in the embodiment of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiment of the present invention. Based on the embodiment 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.

[0049] According to one aspect of the present application, a real-time process control system is provided, which is used to implement process control of semiconductor lithography process equipment. Specifically, the semiconductor lithography process equipment is used to complete the entire process cycle of the semiconductor. For example, Figure 2 and Figure 3 As shown in the figure, the entire process cycle of semiconductors includes steps such as deposition, exposure, development and baking, etching, ion implantation, and resist coating, among which deposition is used to deposit materials through resist coating to form a preliminary structure. Exposure is used to transfer the design pattern to the material using photolithography technology. Development and baking are used to remove unnecessary materials through the development process, and baking is performed to fix the pattern. Etching is used to remove excess materials to form the final semiconductor structure. Ion implantation is used to change the electrical characteristics of the material through ion implantation technology.

[0050] For details, please refer to Figure 2 and Figure 3 As shown, the real-time process control system includes a data acquisition module and a lithography analysis module, wherein the data acquisition module is used to acquire process acquisition parameters of a target process in real time at target intervals in the semiconductor lithography process equipment in the semiconductor process flow, wherein the target process is at least one process in the semiconductor process flow, and the semiconductor process flow is used to characterize the process cycle of a single-chip semiconductor; the lithography analysis module is communicatively connected with the data acquisition module, and the lithography analysis module is used to receive the process acquisition parameters transmitted by the data acquisition module, and perform data analysis on the process acquisition parameters, so as to obtain process adjustment parameters and then feed back the process adjustment parameters to the semiconductor lithography process equipment. The semiconductor lithography process equipment, the data acquisition module and the lithography analysis module are used to form the following. Figure 2 A closed loop is shown, i.e., a real-time process control loop. In the loop, the data acquisition module may be a signal measurement system (SMS), and the data acquisition module may include at least one, for example, Figure 2As shown, there are three data acquisition modules, which respectively acquire the process acquisition parameters in the three target processes of anti-corrosion coating, exposure, and development and baking. It is understandable that the data acquisition module can also include other numbers to obtain process acquisition parameters in different target processes. Among them, in different target processes, the process acquisition parameters may include but are not limited to process parameters, environmental parameters and process result parameters. Among them, the process parameters may include but are not limited to, for example, vapor deposition and substrate material in the target process of deposition. For example, the process parameters may include but are not limited to parameters such as spin coating speed and spin coating acceleration in the target process of anti-corrosion coating. For example, the process parameters may also include parameters such as photoresist characteristics and photoresist thickness in the target process of etching, parameters such as exposure dose in the target process of exposure, and parameters such as developer characteristics and concentration, development time, baking temperature, and baking time in the target process of development and baking. Environmental parameters may include but are not limited to factors that may affect the process results during the process, such as the temperature, humidity, atmospheric pressure, vibration, etc. of the target process. The process result parameters include, but are not limited to, exposure results obtained by optically inspecting the workpiece after development and baking, such as line width uniformity, line width roughness, line wall verticality, pattern defects, etc. Furthermore, the process parameters may also include some measurement data.

[0051] It can be understood that this technical solution is to realize real-time monitoring and parameter adjustment feedback of the monolithic semiconductor process during the monolithic semiconductor process. Compared with the batch adjustment in the prior art, its adjustment has a higher degree of convergence, which helps to reduce product quality problems caused by parameter deviation and improve production efficiency and product quality.

[0052] Further, the semiconductor lithography process equipment is connected in communication with the lithography analysis module, and the semiconductor lithography process equipment is used to update the process acquisition parameters at the target moment based on the process adjustment parameters after receiving the process adjustment parameters fed back by the lithography analysis module, the target moment is the moment before the target interval moment from the current moment, and the current moment is the moment when the semiconductor lithography process equipment receives the process adjustment parameters. In one example, the lithography analysis module is constructed as a lithography analysis model, and the lithography analysis model is obtained by real-time iterative training based on the stored data of the database. When the lithography analysis module completes the analysis of the current process based on the model algorithm, it generates a set of process adjustment parameters. These parameters may include exposure time, light intensity, temperature, etc., which are used to optimize the subsequent lithography process after these process adjustment parameters are sent to the plate conductor lithography process equipment. In this example, the update can be to overwrite the original parameter value, or in some cases, to record the new parameters as historical data for subsequent analysis and tracing.

[0053] In some embodiments, the real-time process control system further includes a data storage module, which is used to receive the process adjustment parameters fed back by the lithography analysis module and then update them. Specifically, after receiving the feedback, the data storage module will compare the new parameters with the previous parameters, identify the content that needs to be updated, and then perform updates that cover other methods.

[0054] It can be understood that the present invention can more effectively manage and track the historical records of process adjustment parameters by storing the data at each moment, whether it is collected or adjusted, in the database, and can provide more comprehensive data for subsequent analysis and optimization, which is conducive to the transparency and traceability of the system. Furthermore, the lithography analysis model can be trained in real time based on the stored data in the database, so that the system can learn and optimize in real time according to the latest data, so as to better adapt to changes in the process.

[0055] In some embodiments, the real-time process control system further includes an abnormality monitoring module, which is electrically connected to the semiconductor lithography process equipment. The abnormality monitoring module is used to monitor whether the process acquisition parameters acquired by the data acquisition module are abnormal, so as to respond when abnormal process acquisition parameters are determined. In some embodiments, the real-time process control system further includes a compensation module, which is communicatively connected to the abnormality monitoring module and the data acquisition module. The compensation module is used to compensate for the abnormal process acquisition parameters after receiving the response signal of the abnormality monitoring module, and update the abnormal process acquisition parameters based on the compensated process compensation parameters. Specifically, the abnormality monitoring module receives the process acquisition parameters from the data acquisition module. These parameters may include but are not limited to temperature, pressure, light intensity, exposure time, etc. After acquiring these data, the abnormality monitoring module can determine whether the parameters are abnormal based on a preset threshold or standard. For example, if the temperature exceeds the safety range or the light intensity fluctuates too much, the module will mark these parameters as abnormal. Once it is determined that there are abnormal process acquisition parameters, the abnormality monitoring module will generate a response signal to notify the compensation module and other related systems.

[0056] It can be understood that in this application scheme, by monitoring whether the process acquisition parameters are abnormal through the abnormal monitoring module, potential process problems can be effectively discovered before the problems occur, and timely maintenance and adjustment of the process can be achieved, thereby improving production efficiency and product quality; further, through the compensation module, the abnormal process acquisition parameters can be compensated and adjusted when certain parameters are found to be abnormal, thereby reducing the impact of the abnormality on the process and ensuring the stability and accuracy of the process.

[0057] According to another aspect of the present application, a real-time process control method is disclosed. The real-time process control method is implemented based on any of the above-mentioned real-time process control systems, such as Figure 4 As shown, the real-time process control method includes:

[0058] S100, controlling a data acquisition module to acquire process acquisition parameters of a target process in real time at a target interval in a semiconductor process flow in a semiconductor lithography process device, wherein the target process is at least one process in a semiconductor process flow, and the semiconductor process flow is used to characterize a process cycle of a single semiconductor.

[0059] S102, control the lithography analysis module to receive the process acquisition parameters transmitted by the data acquisition module, and perform data analysis on the process acquisition parameters to obtain process adjustment parameters and then feed back the process adjustment parameters to the semiconductor lithography process equipment. The lithography analysis module is in communication connection with the data acquisition module.

[0060] S104, controlling the semiconductor lithography process equipment to update the process acquisition parameters at the target moment based on the process adjustment parameters after receiving the process adjustment parameters fed back by the lithography analysis module, the target moment being the moment before the target interval moment from the current moment, the current moment being the moment when the semiconductor lithography process equipment receives the process adjustment parameters, and the semiconductor lithography process equipment is in communication connection with the lithography analysis module.

[0061] In some embodiments, the method further includes constructing a lithography analysis model for use as a lithography analysis module, and constructing the lithography analysis model includes:

[0062] Acquire the stored data in the database, the stored data including process parameters, equipment attribute parameters and material attribute parameters, the equipment attribute parameters are used to characterize the attribute information of semiconductor photolithography process equipment, the material attribute parameters are used to characterize the attribute information of processed raw material wafers, the process parameters are the process acquisition parameters before and after the update, and the process parameters include the process parameters, environmental parameters and process result parameters of the target process;

[0063] After cleaning the process acquisition parameters, equipment attribute parameters and material attribute parameter data in the database, model training is performed to obtain a lithography analysis model.

[0064] In some embodiments, the method further comprises:

[0065] The control abnormality detection module monitors whether the process acquisition parameters acquired by the data acquisition module are abnormal, so as to respond when abnormal process acquisition parameters are determined.

[0066] In some embodiments, the method further comprises:

[0067] The control compensation module is used to compensate the abnormal process acquisition parameters after receiving the response signal from the abnormal monitoring module, and update the abnormal process acquisition parameters based on the compensated process compensation parameters.

[0068] The method not introduced here can refer to the above introduction to the system. The principle is the same and will not be repeated here.

[0069] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A real-time process control system, characterized in that: The real-time process control system is used to realize process control of semiconductor photolithography process equipment, and the real-time process control system includes: A data acquisition module, used for acquiring process acquisition parameters of a target process in real time at a target interval in the semiconductor process flow of the semiconductor lithography process equipment, wherein the target process is at least one process in the semiconductor process flow, and the semiconductor process flow is used to characterize the process cycle of a single semiconductor; A lithography analysis module, the lithography analysis module is in communication with the data acquisition module, the lithography analysis module is used to receive the process acquisition parameters transmitted by the data acquisition module, and perform data analysis on the process acquisition parameters to obtain process adjustment parameters, and then feed back the process adjustment parameters to the semiconductor lithography process equipment; The semiconductor lithography process equipment is communicatively connected with the lithography analysis module. After receiving the process adjustment parameters fed back by the lithography analysis module, the semiconductor lithography process equipment is used to update the process acquisition parameters at a target moment based on the process adjustment parameters. The target moment is a moment before the target interval moment from the current moment, and the current moment is the moment when the semiconductor lithography process equipment receives the process adjustment parameters.

2. The real-time process control system according to claim 1, characterized in that: The real-time process control system further comprises a data storage module, and the data storage module is used for updating the process adjustment parameters after receiving the process adjustment parameters fed back by the photolithography analysis module.

3. The real-time process control system according to claim 2, characterized in that: The lithography analysis module is constructed as a lithography analysis model, and the lithography analysis model is obtained by real-time iterative training based on the storage data of the database.

4. The real-time process control system according to claim 1, characterized in that: The real-time process control system also includes an abnormality monitoring module, which is electrically connected to the semiconductor lithography process equipment. The abnormality monitoring module is used to monitor whether the process acquisition parameters acquired by the data acquisition module are abnormal, so as to respond when abnormal process acquisition parameters are determined.

5. The real-time process control system according to claim 4, characterized in that: The real-time process control system also includes a compensation module, which is communicatively connected to the abnormal monitoring module and the data acquisition module. The compensation module is used to compensate the abnormal process acquisition parameters after receiving a response signal from the abnormal monitoring module, and update the abnormal process acquisition parameters based on the compensated process compensation parameters.

6. A real-time process control method, the real-time process control method is implemented based on the real-time process control system according to any one of claims 1 to 5, the real-time process control method comprising: Controlling the data acquisition module to acquire process acquisition parameters of a target process in real time at a target interval in the semiconductor process flow of the semiconductor lithography process equipment, wherein the target process is at least one process in the semiconductor process flow, and the semiconductor process flow is used to characterize the process cycle of a single semiconductor; Controlling the photolithography analysis module to receive the process acquisition parameters transmitted by the data acquisition module, and performing data analysis on the process acquisition parameters to obtain process adjustment parameters and then feeding back the process adjustment parameters to the semiconductor photolithography process equipment, wherein the photolithography analysis module is in communication connection with the data acquisition module; After the semiconductor lithography process equipment receives the process adjustment parameters fed back by the lithography analysis module, the process acquisition parameters at the target moment are updated based on the process adjustment parameters, wherein the target moment is the moment before the target interval moment from the current moment, and the current moment is the moment when the semiconductor lithography process equipment receives the process adjustment parameters, and the semiconductor lithography process equipment is communicatively connected with the lithography analysis module.

7. The real-time process control method according to claim 6, characterized in that: The method further includes constructing a lithography analysis model for use as a lithography analysis module, wherein constructing the lithography analysis model includes: Acquire stored data in a database, wherein the stored data includes process parameters, equipment attribute parameters, and material attribute parameters, wherein the equipment attribute parameters are used to characterize attribute information of the semiconductor photolithography process equipment, and the material attribute parameters are used to characterize attribute information of the processed raw material wafers, wherein the process parameters are the process acquisition parameters before and after the update, and the process parameters include process parameters, environmental parameters, and process result parameters of the target process; The process acquisition parameters, the equipment attribute parameters and the material attribute parameter data in the database are cleaned and then model training is performed to obtain the lithography analysis model.

8. The real-time process control method according to claim 6, characterized in that: The method further comprises: The control abnormality detection module monitors whether the process acquisition parameters acquired by the data acquisition module are abnormal, so as to respond when abnormal process acquisition parameters are determined.

9. The real-time process control method according to claim 8, characterized in that: The method further comprises: The control compensation module is used to compensate the abnormal process acquisition parameters after receiving the response signal of the abnormal monitoring module, and update the abnormal process acquisition parameters based on the compensated process compensation parameters.

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