Selective surface exposure, cleans and conditioning of the germanium film in a Ge photodetector

Abstract

A method of protecting a sensitive layer from harsh chemistries. The method includes forming a first sensitive layer, forming a second layer upon the first layer, then forming a third layer over the second layer. The third layer is utilized as a mask during patterning of the second layer. During patterning, however, the second layer is only partially etched, thus leaving a buffer layer overlying the first layer. The third layer is completely removed while the buffer layer protects the first layer from the harsh chemicals that are utilized to remove the third layer. Then, the buffer layer is carefully removed down to the surface of the first layer.

Dependencies are inferred from the claim text.