Forming a silicon diaphragm in a cavity by anodizing, oxidizing, and etching or by directly etching the porous silicon

摘要

Method of forming a diaphragm (11) supported in a cavity (22), comprising the steps of: a. implant in a substrate (8) a p-type layer (50); b. deposit an n-type epitaxial layer (18) on the substrate (8); c. implant spaced sinkers (58) through the epitaxial layer (18) and into electrical connection with the layer (50); d. anodize the substrate (8) to form porous silicon of the sinkers (58) and said layer (50); e. oxidize the porous silicon to form silicon dioxide ; and f. etch the silicon dioxide to form the cavity (22) and diaphragm (11). A direct etching of porous silicon is also proposed.