In-situ endpoint detection for membrane formation

摘要

A method of in-situ endpoint detection for membrane formation including directing light from a light source onto one side of a membrane structure having at least one etchable component for the formation of a membrane and etching the membrane structure so as to form the membrane while sensing the light from the light source on an opposite side of the membrane structure in-situ during the etching to detect a thickness of the membrane. Generally, the etching step includes fountain cup etching with the light source being a fiber optic mounted in the fountain cup and a detector mounted in the cap.