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CN-122018587-A - Pressure control method for semiconductor reaction cavity

CN122018587ACN 122018587 ACN122018587 ACN 122018587ACN-122018587-A

Abstract

The invention provides a pressure control method of a semiconductor reaction cavity, which relates to the technical field of semiconductor manufacturing, and comprises the steps of presetting a target pressure value, obtaining an actual pressure value, judging whether a difference value between the actual pressure value and the target pressure value meets preset conditions, executing a first pressure control mode if the difference value meets the preset conditions, calculating total time required for adjusting an initial pressure value to the target pressure value by setting a total target pressure change rate in the first pressure control mode, dividing the total time into a plurality of control periods, and dynamically adjusting the set pressure change rate of a next period to the target pressure value in each control period according to the ratio of the actual pressure change rate to the total target pressure change rate. The invention realizes uniformity and stability of pressure adjustment and effectively inhibits pressure fluctuation by dividing control period and dynamically adjusting pressure change rate.

Inventors

  • YANG CHENGYIN

Assignees

  • 江苏天芯微半导体设备有限公司

Dates

Publication Date
20260512
Application Date
20251112

Claims (11)

  1. 1. A method for controlling pressure in a semiconductor reaction chamber, the method comprising: Presetting a target pressure value P f of the semiconductor reaction cavity, and acquiring an actual pressure value of the semiconductor reaction cavity; Judging whether a pressure difference value between the actual pressure value and the target pressure value P f meets a preset condition or not, and executing a first pressure control mode when the pressure difference value meets the preset condition; wherein the first pressure control mode includes the steps of: Taking the initial actual pressure value of the semiconductor reaction cavity as an initial pressure value P 0 , and presetting a total target pressure change rate V d of the semiconductor reaction cavity from the initial pressure value P 0 to the target pressure value P f ; Calculating a total time required for the semiconductor reaction chamber to be adjusted from the initial pressure value P 0 to the target pressure value P f according to a total pressure difference between the initial pressure value P 0 and the target pressure value P f and the total target pressure change rate V d ; dividing the total time into n control periods with the time length of t, wherein n is more than or equal to 2; for the ith control period, i is an integer of 1 to n, performing a pressure adjustment operation, specifically including: Acquiring an actual pressure value P i-1 of the semiconductor reaction chamber at the beginning of the ith control period and an actual pressure value P i at the end of the ith control period; Calculating an actual pressure change rate V i in the ith control period according to the actual pressure value P i-1 at the beginning, the actual pressure value P i at the end and the time length t; Calculating a ratio E i of the actual pressure change rate V i to the total target pressure change rate V d ; Setting V d /E i as the set pressure change rate V i+1 of the (i+1) th control period; And repeating the pressure regulating operation, increasing i from 1 to n, and regulating the actual pressure value of the semiconductor reaction cavity to the target pressure value.
  2. 2. The method for controlling pressure in a semiconductor reaction chamber according to claim 1, wherein the total time is calculated by the formula: , Where T is the total time, P f is the target pressure value, P 0 is the initial pressure value, and V d is the total target pressure rate of change.
  3. 3. The method for controlling pressure in a semiconductor reaction chamber according to claim 1, wherein the actual pressure change rate is calculated by the formula: , where V i is the actual pressure change rate, P i-1 and P i are the actual pressure value at the start of the ith control period and the actual pressure value at the end of the ith control period, respectively, and t is the time length of each control period.
  4. 4. The method according to claim 1, wherein the semiconductor reaction chamber is configured to adjust the pressure in the chamber through a pressure regulating valve, the first pressure control mode is a self-learning pressure control mode, and the self-learning pressure control mode synchronously records an actual pressure value of the reaction chamber and a valve opening value of the pressure regulating valve corresponding to the actual pressure value in a predetermined sampling period during at least one history process, so as to obtain a relation curve of the actual pressure value and the valve opening value.
  5. 5. The method of controlling pressure of a semiconductor reaction chamber according to claim 4, further comprising, after obtaining the set pressure change rate V i+1 for the (i+1) th control cycle in the pressure adjusting operation: For the (i+1) th control period, acquiring an initial valve opening value M i at the beginning of the (i+1) th control period, and calculating to obtain an estimated pressure value P i+1 ' at the end of the (i+1) th control period according to an actual pressure value P i at the beginning of the (i+1) th control period, the set pressure change rate V i+1 and the time length t; Substituting the estimated pressure value P i+1 'at the end of the (i+1) th control period into the relation curve to obtain a target valve opening value M i+1 corresponding to the estimated pressure value P i+1 '; calculating an opening difference value between the target valve opening value M i+1 and the initial valve opening value M i , and calculating a valve opening change rate K i+1 of the (i+1) th control period based on the opening difference value and the time length t; And controlling the pressure regulating valve to act at a valve opening change rate K i+1 , so that the actual pressure of the semiconductor reaction cavity is changed according to the set pressure change rate V i+1 in the (i+1) th control period.
  6. 6. The method of claim 5, wherein the estimated pressure value is calculated by the formula: , Wherein, P i+1 ' is the estimated pressure value at the end of the (i+1) th control period, P i is the actual pressure value at the beginning of the (i+1) th control period, V i+1 is the set pressure change rate of the (i+1) th control period, and t is the time length of each control period.
  7. 7. The method of controlling pressure in a semiconductor reaction chamber according to claim 5, wherein the calculation formula of the valve opening rate of the (i+1) th control period is: , wherein K i+1 is the valve opening change rate of the (i+1) th control period, M i+1 is the target valve opening value, M i is the initial valve opening value, and t is the time length of each control period.
  8. 8. The method for controlling pressure in a semiconductor reaction chamber according to claim 1, wherein the preset condition is: the ratio of the absolute value of the pressure difference between the actual pressure value of the semiconductor reaction chamber and the target pressure value P f to the target pressure value P f is greater than a preset ratio.
  9. 9. The method of claim 8, further comprising executing a second pressure control mode when the pressure difference does not satisfy a preset condition, the second pressure control mode being a PID pressure control mode, and a derivative parameter D of the PID pressure control mode being zero.
  10. 10. The method for controlling pressure in a semiconductor reaction chamber according to claim 8, wherein the preset ratio is in a range of 5% -10%.
  11. 11. The method of pressure control of a semiconductor reaction chamber of claim 9, wherein the semiconductor reaction chamber is configured with a self-learning module and a PID module, wherein: The self-learning module is configured to record the actual pressure value of the semiconductor reaction chamber and the valve opening value of the corresponding pressure regulating valve in the first pressure control mode, and is further configured to record the actual pressure value of the semiconductor reaction chamber and the valve opening value of the corresponding pressure regulating valve and the PID control parameter of the corresponding PID pressure control mode in the second pressure control mode; The PID module is configured to obtain corresponding PID control parameters from the self-learning module according to the actual pressure value of the current semiconductor reaction chamber in the second pressure control mode.

Description

Pressure control method for semiconductor reaction cavity Technical Field The invention relates to the technical field of semiconductor manufacturing, in particular to a pressure control method of a semiconductor reaction cavity. Background Pressure control within a semiconductor reaction chamber is a critical element in the semiconductor manufacturing process. The fabrication of semiconductor devices typically involves a variety of complex chemical reactions and physical processes that are sensitive to the pressure conditions within the semiconductor reaction chamber. Accurate and stable pressure control can ensure the stability and consistency of the reaction process, and can effectively improve the yield and performance of the product. Therefore, the pressure control method of the semiconductor reaction chamber has been the focus of research and development in the field of semiconductor manufacturing. However, the uniformity of pressure change is often difficult to achieve in the existing pressure control method of the semiconductor reaction chamber, and the pressure change rate fluctuates in the process of pressure adjustment. Such fluctuations not only lead to deviations between the actual pressure in the semiconductor reaction chamber and the target pressure, but may also cause unstable phenomena during the reaction, thereby affecting the quality and performance of the semiconductor device. Disclosure of Invention The invention aims to provide a pressure control method of a semiconductor reaction cavity, which is used for solving the problems that the pressure change rate fluctuates in the process of adjusting the pressure of the cavity, uniform control is difficult to realize, and further the deviation between the actual pressure and the target pressure, the unstable reaction process and the quality and performance of a semiconductor device are damaged. In order to achieve the above object, the present invention is realized by the following technical scheme: a pressure control method of a semiconductor reaction chamber, the pressure control method comprising: Presetting a target pressure value P f of the semiconductor reaction cavity, and acquiring an actual pressure value of the semiconductor reaction cavity; Judging whether a pressure difference value between the actual pressure value and the target pressure value P f meets a preset condition or not, and executing a first pressure control mode when the pressure difference value meets the preset condition; wherein the first pressure control mode includes the steps of: Taking the initial actual pressure value of the semiconductor reaction cavity as an initial pressure value P 0, and presetting a total target pressure change rate V d of the semiconductor reaction cavity from the initial pressure value P 0 to the target pressure value P f; Calculating a total time required for the semiconductor reaction chamber to be adjusted from the initial pressure value P 0 to the target pressure value P f according to a total pressure difference between the initial pressure value P 0 and the target pressure value P f and the total target pressure change rate V d; dividing the total time into n control periods with the time length of t, wherein n is more than or equal to 2; for the ith control period, i is an integer of 1 to n, performing a pressure adjustment operation, specifically including: Acquiring an actual pressure value P i-1 of the semiconductor reaction chamber at the beginning of the ith control period and an actual pressure value P i at the end of the ith control period; Calculating an actual pressure change rate V i in the ith control period according to the actual pressure value P i-1 at the beginning, the actual pressure value P i at the end and the time length t; Calculating a ratio E i of the actual pressure change rate V i to the total target pressure change rate V d; Setting V d/Ei as the set pressure change rate V i+1 of the (i+1) th control period; And repeating the pressure regulating operation, increasing i from 1 to n, and regulating the actual pressure value of the semiconductor reaction cavity to the target pressure value. In some embodiments, the total time is calculated as: Where T is the total time, P f is the target pressure value, P 0 is the initial pressure value, and V d is the total target pressure rate of change. In some embodiments, the actual pressure change rate is calculated as: where V i is the actual pressure change rate, P i-1 and P i are the actual pressure value at the start of the ith control period and the actual pressure value at the end of the ith control period, respectively, and t is the time length of each control period. In some embodiments, the semiconductor reaction chamber is configured to adjust the pressure in the chamber through a pressure regulating valve, the first pressure control mode is a self-learning pressure control mode, and the self-learning pressure control mode synchronously records an actual pr