REAL-TIME MEASUREMENT OF ETCHING RATE IN CHEMICAL ETCHING PROCESS

摘要

PURPOSE: To provide a non-contact method for monitoring a chemical etching process in a device in real time when etching at least one wafer during a wet- type chemical etching bath. ;CONSTITUTION: A stage for forming two conductive electrodes in a wet-type chemical bath so that they approach a wafer but do not contact it, a stage for monitoring electrical characteristics between two electrodes where the prescribed change of the electrical characteristics indicates the prescribed conditions of an etching process as a function of time in the etchant bath of at least one wafer, and a stage for recording a plurality of values of electrical characteristics as a function of time during etching are included. An instantaneous etching rate an average etching rate, and the etching end point can be determined from a plurality of recorded values and the corresponding time. Therefore, such method and device are useful, especially for a wet-type chemical etching station.;COPYRIGHT: (C)1996,JPO