Abstract: 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.

Abstract: A method and apparatus for planarizing photoresist and/or metal microstructure layers is provided. Planarization is achieved by removing material from a workpiece by lapping using a diamond containing lapping slurry. A lapping machine is furnished with a lapping plate made of a soft metal material. The lapping plate is furnished with ridges of controlled height using a diamond conditioning ring with a specified grit size. Free diamonds in a liquid slurry are then sprayed onto the plate and embedded therein by a second conditioning ring. After the lapping plate is conditioned, the piece to be lapped is mounted on the lapping plate. A vacuum hold fixture or flat steel or glass mounting plate may be used. During lapping, additional diamond slurry is sprayed onto the lapping plate and driven into the plate by a ceramic conditioning ring. The size of diamonds in the diamond slurry are selected to control the shear forces applied to the surface being lapped and to achieve a desired surface finish.