SPC-based wafer production process flow quality control system and control method

Abstract

The invention discloses an SPC-based wafer production process flow quality control system and control method. The system comprises a historical data management module, an alarm management module, a plan management module, a rule management module, a CPK report management module and a control chart module. The historical data management module is used for storing data uploaded to the system in the production process; the alarm management module is used for generating alarm information when the parameters violate the SPC control rule; the plan management module is used for creating, querying, modifying and deleting a management and control plan of the operation; the rule management module is used for displaying control rules defined by the system; the CPK report management module is used for generating a process capability analysis report according to the historical data; and the control chart module is used for displaying a control chart of the parameters in real time. According to the invention, accurate monitoring and analysis can be realized, problem delay identification is reduced, production interruption and quality defect risks are reduced, and production efficiency and product quality are improved.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of semiconductor wafer processing technology, and particularly relates to a quality control system and method for wafer production process flow based on SPC. Background Art

[0002] In the field of semiconductor wafer processing, the Manufacturing Execution System (MES) plays a crucial role, supporting the entire manufacturing process from single crystal wafers to final products. This process includes multiple delicate and complex processes such as oxidation diffusion, lithography, etching, washing, deposition, etc. The core functions of MES include: production scheduling and planning, process management, equipment management, and material management. At the same time, as the data center on the production line, MES is responsible for real-time collection, integration, and analysis of key production information. For example, MES can collect data such as equipment status, process parameters, and product quality inspection results.

[0003] At the same time, in semiconductor wafer manufacturing processes, Statistical Process Control (SPC) is a key technology to ensure product quality and production process stability. The SPC system monitors key process parameters using control charts by collecting and analyzing production data to detect and correct deviations in a timely manner. However, there are several limitations in the existing SPC systems in practical applications:

[0004] 1. Limitations of standardized control charts. Existing SPC systems usually use standardized control charts such as the mean (X-bar) chart and the range (R) chart. Although these charts are widely used in various production environments, in semiconductor wafer manufacturing processes, the requirements for accuracy and process control are extremely high, and the system is required to customize control charts according to specific production processes. However, existing SPC systems often lack this customization ability and cannot provide accurate monitoring and analysis for specific process flows, thus affecting the optimization of the production process and the improvement of quality.

[0005] 2. Challenges of real-time monitoring. Changes in the semiconductor production process can be very rapid, posing higher requirements for real-time monitoring systems. Although existing SPC systems provide real-time monitoring functions, they may not be able to quickly adapt to rapid changes in the production process, resulting in untimely responses to problems and increasing the risks of production interruptions and quality defects. Summary of the Invention

[0006] In view of the technical problems existing in the prior art, the present invention provides a quality control system and method for wafer production process flow based on SPC that can achieve accurate monitoring and analysis, reduce the delayed identification of problems, reduce the risks of production interruptions and quality defects, and improve production efficiency and product quality.

[0007] To solve the above technical problems, the technical solution proposed by the present invention is:

[0008] A quality control system for wafer production process based on SPC, including a historical data management module, an alarm management module, a plan management module, a rule management module, a CPK report management module and a control chart module;

[0009] The historical data management module is used to store the data uploaded to the system during the production process;

[0010] The alarm management module is used to generate alarm information when parameters violate the SPC control rules;

[0011] The plan management module is used to create, query, modify and delete the control plans of jobs;

[0012] The rule management module is used to display the control rules defined by the system;

[0013] The CPK report management module is used to generate process capability analysis reports according to historical data;

[0014] The control chart module is used to display the control charts of parameters in real time.

[0015] Preferably, the historical data management module includes a data analysis and calculation unit, a rule outlier determination unit and a historical data management unit;

[0016] The data analysis and calculation unit is used to perform complex statistical calculations;

[0017] The rule outlier determination unit is used to determine whether the data violates the SPC control rules;

[0018] The historical data management unit is used to manage all the data uploaded from MES to the SPC system, and display the basic information of the data and the violation information of the data.

[0019] Preferably, the alarm management module includes an alarm information viewing unit and a repair alarm unit;

[0020] The alarm information viewing unit is used to view alarm information. If the data of this job violates the rules corresponding to the set control chart, an alarm will be generated on this page;

[0021] The repair alarm unit is used to repair the alarm and fill in the repair reason and repair time.

[0022] Preferably, the plan management module includes a job basic information configuration unit, a control chart setting unit and a control rule setting unit;

[0023] The job basic information configuration unit is used to input and manage the basic information of the job;

[0024] The control chart setting unit is used to configure the control chart;

[0025] The control rule setting unit is used to set control rules for monitoring the production process to ensure that the process meets the established quality standards.

[0026] Preferably, the rule management module adopts statistical data analysis algorithms, specifically including: a single point exceeding the upper and lower control limits; a single point exceeding the upper and lower specification limits; two out of three points exceeding two standard deviations; four out of five points exceeding one standard deviation; eight consecutive points above or below the center line; eight consecutive points greater than or less than one standard deviation; six consecutive points rising or falling; fifteen consecutive points within one standard deviation; fourteen consecutive points fluctuating up and down; seven consecutive points strictly rising or strictly falling; nine consecutive points deviating to one side.

[0027] Preferably, the CPK report management module includes a report generation unit and a report status management unit;

[0028] The report generation unit is responsible for creating a CPK report, and this unit creates a detailed CPK report based on the data provided by the data analysis and calculation unit;

[0029] The report status management unit is used to control the activation status of the report; when the report status is set to ACTIVE, this unit will ensure that the report data is automatically updated at a preset time; if the report status is set to INACTIVE, the update of the report data will be stopped.

[0030] Preferably, the control chart includes an upper specification limit USL, a lower specification limit LSL, an upper control limit UCL, a lower control limit LCL, and a center line CL.

[0031] The present invention also discloses a control method based on the above-mentioned SPC-based wafer production process quality control system, including the steps:

[0032] S1. The user sets a control plan through the plan management module, including setting the basic information of the operation, selecting the type of control chart, and control rules;

[0033] S2. MES uploads production data to the system; the calculation module in the system is responsible for statistical analysis of the data; the rule outlier unit then evaluates whether the data meets the established control rules; if there is a violation, the system will automatically prompt data abnormality on the data upload interface of MES and trigger the automatic suspension of the relevant production process to prevent the continued production of non-conforming products;

[0034] S3. Select the corresponding operation according to different products or equipment. After selecting the operation, the system displays the preset control chart in the control plan of this operation, views the statistical parameters of the operation data in a graphical manner, and filters the data according to a specific time range;

[0035] S4. The alarm management module displays all alarm information related to data and provides an alarm repair function;

[0036] S5. The CPK report management module generates periodic reports to evaluate the performance and capabilities of the production process;

[0037] S6. The historical data management module stores all uploaded data and its violation information.

[0038] Preferably, in step S1, the jobs are divided into two types: offline jobs and online jobs; when configuring a job, it is necessary to define the job name, job type, job description, and the number of sampling points of the wafer; for the NonRT job type, the device number needs to be specified; for the RT job type, the product number, process number, sub-process number, and step number need to be specified.

[0039] Preferably, the control chart includes a standardized control chart and a customized control chart.

[0040] Compared with the prior art, the advantages of the present invention are as follows:

[0041] By providing a customized control chart, the present invention can better adapt to the unique requirements of the semiconductor wafer processing technology, achieve more accurate monitoring and analysis. In addition, the enhanced real-time monitoring function in the solution can quickly adapt to changes in the production process, reduce the delayed identification of problems, lower the risks of production interruption and quality defects, and improve production efficiency and product quality. Brief Description of the Drawings

[0042] Figure 1 It is a block structure diagram of the SPC-based wafer production process quality control system of the present invention in an embodiment.

[0043] Figure 2 It is a flowchart of the SPC-based wafer production process quality control method of the present invention in an embodiment. Detailed Embodiments

[0044] The present invention will be further described below in conjunction with the specification drawings and specific embodiments.

[0045] As Figure 1 shown, the SPC-based wafer production process quality control system provided by the embodiment of the present invention is specifically to control the wafer manufacturing process by collecting and analyzing wafer data and semiconductor equipment data. The specific structure includes a historical data management module, an alarm management module, a plan management module, a rule management module, a CPK report management module, and a control chart module;

[0046] The historical data management module is used to store the data uploaded to the system during the production process;

[0047] An alarm management module, which is used to generate alarm information when parameters violate the SPC control rules;

[0048] A plan management module, which is used to create, query, modify, and delete the control plans of jobs;

[0049] A rule management module, which is used to display 13 control rules defined by the system;

[0050] A CPK report management module, which is used to generate process capability analysis reports based on historical data;

[0051] A control chart module, which is used to display the control chart of parameters in real time.

[0052] Specifically, the historical data management module includes a data analysis and calculation unit, a rule discrimination unit, and a historical data management unit.

[0053] Among them, the data analysis and calculation unit is used to perform complex statistical calculations, such as the calculation of mean, variance, standard deviation, and process capability indices (Cpk, Ppk); this unit can process a large amount of data and provide fast and accurate calculation results.

[0054] The rule discrimination unit is used to determine whether the data violates the SPC control rules. The core function of this unit is to analyze the production data using precise algorithms to determine whether the data points violate the preset control rules; once the data violates these rules, this unit will clearly mark the relevant data batches and point out the specific rule content violated.

[0055] The historical data management unit is used to manage all the data uploaded from MES to the SPC system, and display the basic information of the data and the violation information of the data, that is, which control rules are violated.

[0056] Specifically, the alarm management module includes an alarm information viewing unit and an alarm repair unit.

[0057] Among them, the alarm information viewing unit is used to view the alarm information. If the data of this job violates the rules corresponding to the set control chart, an alarm will be generated on this page. The alarm is targeted at a certain rule of a certain control chart of a certain job, that is, there may be multiple rule violation messages for the control chart of a single job.

[0058] The alarm repair unit is used to repair the alarm, and the repair reason and repair time need to be filled in. When the user identifies and solves the problem that causes the alarm, the alarm status will be updated.

[0059] Specifically, the plan management module includes a job basic information configuration unit, a control chart setting unit, and a control rule setting unit.

[0060] The job basic information configuration unit is used to input and manage the basic information of the job, such as job description, related equipment, related batches, related processes, operator information, the number of wafer sampling points, etc.

[0061] The control chart setting unit is used to configure control charts. The control chart setting unit provides two types of control charts for users to choose from. The first is the standardized control chart, including widely used X-bar chart, R chart, etc., which is suitable for conventional quality management and process monitoring. The second is the customized control chart, which is a control chart defined according to a specific production process, such as calculating etching uniformity (ER_U), grain size interpolation (Grain_Diff), and film thickness uniformity (FTU) in wet metrology, etc., to show the distribution of specific process parameters. In addition, the user also needs to set key thresholds for the selected control chart, including upper and lower control limits, upper and lower specification limits, and center line.

[0062] The control rule setting unit is used to set control rules for monitoring the production process to ensure that the process meets the established quality standards.

[0063] Specifically, the rule management module adopts industry-standard statistical data analysis algorithms, specifically including: a single point exceeding the upper and lower control limits; a single point exceeding the upper and lower specification limits; 2 out of 3 points exceeding 2 times the standard deviation; 4 out of 5 points exceeding 1 time the standard deviation; 8 consecutive points above or below the center line; 8 consecutive points greater than or less than 1 time the standard deviation; 6 consecutive points rising or falling; 15 consecutive points within 1 time the standard deviation; 14 consecutive points fluctuating up and down; 7 consecutive points strictly rising or strictly falling; 9 consecutive points skewed to one side.

[0064] Specifically, the CPK report management module includes a report generation unit and a report status management unit.

[0065] The report generation unit is responsible for creating CPK reports. This unit creates detailed CPK reports based on the data provided by the data analysis and calculation unit. This unit not only shows key process capability indices, such as Cpk and Ppk values, but also integrates key statistical data, including mean, standard deviation, range, etc., to provide users with a performance snapshot of the production process.

[0066] The report status management unit is used to control the activation status of the report. When the report status is set to ACTIVE, this unit will ensure that the report data is automatically updated at a preset time. If the report status is set to INACTIVE, the update of the report data will be stopped.

[0067] Specifically, the control chart module is used to view the statistical parameters of data and graphically display the distribution and trend of process variables. The control chart has an upper specification limit (USL), a lower specification limit (LSL), an upper control limit (UCL), a lower control limit (LCL), and a center line (CL). By observing the distribution of data points relative to the control limits and specification limits, users can determine whether there are situations in the production process that violate the preset rules, such as data points exceeding the control limits or specification limits.

[0068] By providing customized control charts, the present invention better adapts to the unique requirements of semiconductor wafer processing technology, enabling more precise monitoring and analysis. In addition, the enhanced real-time monitoring function in the solution can quickly adapt to changes in the production process, reduce the delayed identification of problems, lower the risks of production interruptions and quality defects, and improve production efficiency and product quality.

[0069] As Figure 2 shown, an embodiment of the present invention further provides a control method for a quality control system of a wafer production process flow based on the above-mentioned SPC-based wafer production process flow, including the following steps:

[0070] S1. The user sets a control plan through the plan management module, including setting the basic information of the operation, selecting a suitable control chart type, and determining the control rules to be applied;

[0071] S2. MES uploads production data to the system. The calculation module in the system is responsible for statistical analysis of the data. The out-of-control rule unit then evaluates whether the data complies with the established control rules. If there is a violation, the system will automatically prompt data anomalies on the data upload interface of MES and trigger the automatic suspension of the relevant production process to prevent the continued production of non-conforming products;

[0072] S3. The user can select the corresponding operation according to different products or equipment. After selecting the operation, the system will display the control chart preset in the control plan of the operation, enabling the viewing of the statistical parameters of the operation data in a graphical manner and allowing data screening based on a specific time range;

[0073] S4. The alarm management module displays all alarm information related to the data and provides an alarm repair function. The user can view the alarm details, including the specific rules and time of violation, and take corresponding handling measures;

[0074] S5. The user generates periodic reports, such as weekly reports, monthly reports, quarterly reports, or annual reports, through the CPK report management module to evaluate the performance and capabilities of the production process;

[0075] S6. The historical data management module stores all uploaded data and its violation information. Users can query historical data according to different conditions and export the query results as an Excel table when needed for further analysis and record keeping.

[0076] By providing customized control charts, the present invention can better adapt to the unique requirements of semiconductor wafer processing technology, meet the needs of the complexity and high specialization of semiconductor wafer processing technology, and thus achieve more accurate monitoring and analysis. In addition, in response to the challenges of rapid changes in the semiconductor production process, the present invention can adapt to changes in the production process faster by enhancing the real-time monitoring function. This rapid response mechanism reduces the delayed identification of problems, reduces the risk of production interruptions and quality defects, and improves production efficiency and product quality.

[0077] To better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments. The specific steps are as follows:

[0078] Configure basic job information: Jobs are divided into two types: offline (NonRT) jobs and online (RT) jobs; When configuring a job, it is necessary to define the job name, job type, job description, and the number of sampling points of the wafer. For the NonRT job type, the device number needs to be specified. For the RT job type, the product number, process number, sub-process number, and step number need to be specified. In addition, regardless of the job type, it is necessary to specify the type of control chart that this job needs to manage, as well as the rules for verifying the control chart.

[0079] Configure control charts: Control charts are divided into standard control charts and customized control charts. Standard control charts include common mean (Xbar), range (R), standard deviation (S) control charts, and box plots (Box-Plot), etc., which are suitable for a wide range of production environments and general quality control requirements. The customized control chart is designed according to the characteristics of a specific production process, such as calculating etching uniformity ER_U (ERU), grain interpolation (Grain_Diff), film thickness uniformity (FTU), etc. for wet measurement machines, to meet specific process monitoring requirements. Each type of control chart includes upper specification limit (USL), lower specification limit (LSL), upper control limit (UCL), lower control limit (LCL), and center line (CL). When configuring a job, the user needs to select the appropriate control chart type according to the specific characteristics of the production process and quality control requirements, and set the corresponding attribute parameters.

[0080] Configuration control rules: The system provides 13 control rules for users to choose from, namely: a single point exceeding the upper and lower control limits, a single point exceeding the upper and lower specification limits, 2 out of 3 points exceeding 2 standard deviations, 4 out of 5 points exceeding 1 standard deviation, 8 consecutive points above or below the center line, 8 consecutive points greater than or less than 1 standard deviation, 6 consecutive points rising or falling, 15 consecutive points within 1 standard deviation, 14 consecutive points fluctuating up and down, 7 consecutive points strictly rising or strictly falling, 9 consecutive points biased to one side. After the user selects the control rules, two key attributes need to be configured for each rule. One is "whether to generate an alarm when the rule is violated", which determines whether the system issues a warning when an abnormality is detected; the other is "whether to suspend the batch", which determines whether to automatically suspend production when the rule is violated to prevent the problem from spreading.

[0081] Data analysis and processing: MES uploads data to the system, and then the data is stored in the database. The system is equipped with an interface that can call the historical data of a job, the configured control chart type, control parameters, and control rules to provide complete data for the rule violation determination process.

[0082] Rule violation determination: The system calls the interface to obtain the data of the job, and then performs rule violation determination on the uploaded data. Some rules are judged only based on the currently uploaded data, such as checking whether a single data point exceeds the control limits or specification limits of the control chart. Some rules, however, need to consider historical data comprehensively and use more complex algorithms to identify the trends of consecutive data points. According to the preset control rules, the corresponding algorithms are used to analyze the uploaded data to determine whether they violate the control rules.

[0083] Issuing an alarm: Once it is detected that the uploaded data violates the preset rules and these rules have the attribute of generating an alarm, the system will generate a detailed alarm record clearly indicating the rules violated by the data. For real-time monitoring, the alarm information will be directly displayed on the data upload interface of the MES system, prompting the operator that there is a problem with the uploaded data. This immediate feedback ensures that problems can be quickly identified and processed, thereby effectively preventing the spread of potential quality problems and ensuring the quality of the production process.

[0084] Control Chart View: The system provides various types of control charts, including standardized control charts and customized control charts, to meet the monitoring requirements of different production scenarios. These control charts not only display the latest data in real time but also allow users to analyze historical data. With clear identification of specification limits (USL and LSL), control limits (UCL and LCL), and the center line (CL), they help users intuitively determine whether the data is under control. In the control chart operation of RT jobs, users first select a specific product from the system and then select the corresponding job name under that product category to access the control chart and the distribution image of historical data for that job. For the control charts of NonRT jobs, users first select a specific device and then select the job name under that device to view the control chart and the image of historical data for that job.

[0085] Process Capability Analysis: Create a detailed CPK report based on the data collected throughout the entire production process of a single job. This unit not only presents key process capability indices such as Cpk and Ppk, which are crucial for measuring the compliance and stability of the production process, but also integrates other key statistical data such as the mean, standard deviation, etc. Through this comprehensive information, the report generation unit provides users with a comprehensive snapshot of the production process performance. Using these analysis results, users can adjust equipment and process parameters to optimize the production process and improve product quality. For example, if the process capability indices indicate insufficient process performance, users may need to adjust equipment settings or improve the process flow to reduce variation and improve the central tendency of the process. Conversely, if the process capability indices show good process performance, users may need to continue monitoring and maintaining the current operating conditions.

[0086] The specific implementation manners of the present invention are only examples and are not limited to the above. Within the scope of the present invention, various changes and modifications can be made to the present invention. For example, specific control charts and monitoring parameters can be customized according to the specific production scenarios and requirements of the measurement steps in the wafer processing technology, or data from different systems can be collected according to different execution methods.

[0087] The above are only the preferred implementation manners of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the idea of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, several improvements and refinements made without departing from the principle of the present invention should be regarded as within the protection scope of the present invention.

Claims

1. A quality control system for the wafer production process based on SPC, characterized in that, It includes a historical data management module, an alarm management module, a plan management module, a rule management module, a CPK report management module, and a control chart module; The historical data management module is used to store the data uploaded to the system during the production process; The alarm management module is used to generate alarm information when parameters violate the SPC control rules; The plan management module is used to create, query, modify, and delete the control plans for jobs; The rule management module is used to display the control rules defined by the system; The CPK report management module is used to generate process capability analysis reports based on historical data; The control chart module is used to display the control chart of parameters in real time.

2. The quality control system for wafer production process based on SPC according to claim 1, wherein The historical data management module includes a data analysis and calculation unit, a rule discrimination unit, and a historical data management unit; The data analysis and calculation unit is used to perform complex statistical calculations; The rule discrimination unit is used to determine whether the data violates the SPC control rules; The historical data management unit is used to manage all the data uploaded from MES to the SPC system, and display the basic information of the data and the violation information of the data.

3. The quality control system for the wafer production process flow based on SPC according to claim 1, wherein The alarm management module includes an alarm information viewing unit and an alarm repair unit; The alarm information viewing unit is used to view alarm information. If the data of this job violates the rules corresponding to the set control chart, an alarm will be generated on this page; The alarm repair unit is used to repair the alarm and fill in the repair reason and repair time.

4. The quality control system for wafer production process flow based on SPC according to claim 1 or 2 or 3, characterized in that, The plan management module includes a job basic information configuration unit, a control chart setting unit, and a control rule setting unit; The job basic information configuration unit is used to input and manage the basic information of the job; The control chart setting unit is used to configure the control chart; The control rule setting unit is used to set the control rules for monitoring the production process to ensure that the process meets the established quality standards.

5. The quality control system for the wafer production process based on SPC according to claim 1 or 2 or 3, characterized in that, The rule management module adopts statistical data analysis algorithms, specifically including: a single point exceeding the upper and lower control limits; a single point exceeding the upper and lower specification limits; 2 out of 3 points exceeding 2 times the standard deviation; 4 out of 5 points exceeding 1 time the standard deviation; 8 consecutive points above or below the center line; 8 consecutive points greater than or less than 1 time the standard deviation; 6 consecutive points rising or falling; 15 consecutive points within 1 time the standard deviation; 14 consecutive points fluctuating up and down; 7 consecutive points strictly rising or strictly falling; 9 consecutive points deviating to one side.

6. The quality control system for the wafer production process flow based on SPC according to claim 1 or 2 or 3, characterized in that, The CPK report management module includes a report generation unit and a report status management unit; The report generation unit is responsible for creating a CPK report. This unit creates a detailed CPK report based on the data provided by the data analysis and calculation unit; The report status management unit is used to control the activation status of the report; when the report status is set to ACTIVE, this unit will ensure that the report data is automatically updated at a preset time; if the report status is set to INACTIVE, the update of the report data will be stopped.

7. The quality control system for wafer production process based on SPC according to claim 1 or 2 or 3, characterized in that The control chart includes an upper specification limit USL, a lower specification limit LSL, an upper control limit UCL, a lower control limit LCL, and a center line CL.

8. A control method for a quality control system of a wafer production process flow based on SPC according to any one of claims 1-7, characterized in that, It includes steps: S1. The user sets the control plan through the plan management module, including setting the basic information of the operation, selecting the control chart type, and control rules. S2. MES uploads production data to the system; the calculation module in the system is responsible for statistical analysis of the data; the rule deviation unit then evaluates whether the data conforms to the established control rules; if violated, the system will automatically prompt data anomalies on the data upload interface of MES and trigger an automatic suspension of the relevant production process to prevent the continued production of non-conforming products. S3. Select the corresponding operation according to different products or equipment. After selecting the operation, the system displays the control chart preset in the control plan of this operation, views the statistical parameters of the operation data in a graphical way, and filters the data according to a specific time range. S4. The alarm management module displays all alarm information related to the data and provides an alarm repair function. S5. Generate periodic reports through the CPK report management module to evaluate the performance and capabilities of the production process. S6. The historical data management module stores all uploaded data and its violation information.

9. The control method according to claim 8, wherein In step S1, the operations are divided into two types: offline operations and online operations; when configuring an operation, it is necessary to define the operation name, operation type, operation description, and the sampling points of the wafers; for the NonRT operation type, the equipment number needs to be specified; for the RT operation type, the product number, process number, sub-process number, and step number need to be specified.

10. The control method according to claim 8 or 9, characterized in that, The control charts include standardized control charts and customized control charts.

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