Gas flow rate calibrating method

Abstract

The invention discloses a calibrating method of air flow used for checking the air flow of an air supply system of a reaction chamber and includes the steps that when the air supply system is newly provided with an air flow controller MFC, the fixed error Es of the system, the volume Vc of the reaction chamber and the volume Vg of an air supply piping are firstly determined, after the MFC is used for a period of time, the flow error Em of the MFC is determined by referring to the Es, the Vc, and the Vg and considering the temperature difference between the reaction chamber and the air supply piping; then the Em value is compared with a limited fault-tolerance value; when the Em value exceeds the limited fault-tolerance value, the system alarms. The invention reduces the system error caused by the difference between the temperature and the volume and reduces the system error by error calibrating. The invention has the advantages of high calculating precision, fast calculating speed as well as convenient and flexible collocation. The invention is mainly applied to calibrating the air flow of the air supply system for a semiconductor processing device and can also be used for calibrating other air supply systems.

Description

technical field [0001] The invention relates to a gas flow calibration method, in particular to a gas flow calibration method of a gas supply system of semiconductor processing equipment. Background technique [0002] In the process of semiconductor silicon wafer processing, the deposition and etching rate of the film depend on the mass flow rate of the process gas entering the reaction chamber and the pressure of the reaction chamber. Every kind of semiconductor silicon wafer processing equipment and different processes require different gas flow ratios. The error of the process gas flow ratio will cause the process to be unstable, and then affect the overall chip yield. Therefore, the accurate measurement and control of process gas flow rate is very important in semiconductor silicon wafer processing equipment. [0003] At present, on the one hand, a high-precision MFC (mass flow controller) is used to measure and control the flow rate of the process gas, and on the othe...

AI Technical Summary

Problems solved by technology

[0036] This scheme has high calibration accuracy, but Kc is related to temperature T and volume V. For online equipment, it is necessary to ensure that the Kc of the two calibrations is consistent

Since Kc is calculated based on the inert gas MFC, the drift of the inert gas MFC will affect the accuracy of the method. When the ambient temperature changes, it is necessary to re-introduce the gas to determine the Kc value, which also increases the cost and prolongs the calibration. test time

Images