Method for judging etching ending point through pressure variation

Abstract

The invention relates to the field of plasma-enhanced chemical vapor deposition (PECVD) equipment etching, in particular to a method for judging an etching ending point through pressure variation. The method is used for judging washing finish when a cavity of PECVD equipment is washed through etching. The method is characterized in that the cavity, the etching ending point of which needs to be judged, is communicated with an exhaust duct; the exhaust duct is provided with a valve; and the etching ending point is judged by monitoring pressure variation in the cavity. The method has the following beneficial effects: the method is simple and convenient and has high reliability; and the problems such as higher cost in the prior art are solved by adopting the method.

Description

technical field

[0001] The invention relates to the field of etching of PECVD equipment, in particular to a method for judging the end point of etching through pressure changes, which is a method for judging the completion of cleaning when PECVD equipment performs cavity etching and cleaning. Background technique

[0002] Etching technique is a technique for selectively etching or stripping the surface of the semiconductor substrate or the surface covering film according to the mask pattern or design requirements in the semiconductor process.

[0003] Etching and cleaning of PECVD equipment refers to: after the PECVD equipment deposits thin film process, there will be thin film deposited on the inner wall of the cavity and the surface of parts inside the cavity. When the thin film accumulates too much, it will fall off on the wafer, seriously affecting Thin film process. Therefore, they need to be cleaned by etching before the film falls off.

[0004] Etching and cleaning ...

Images