Etching cavity structures in silicon under dielectric membrane

摘要

A semiconductor device includes a semiconductor layer (2) and a dielectric stack (3) on the semiconductor layer. A plurality of etchant openings (24-1,2 . . . ) are formed through the dielectric stack (3) for passage of etchant for etching a plurality of overlapping sub-cavities (4-1,2 . . . ), respectively. The etchant is introduced through the etchant openings to etch a composite cavity (4) in the semiconductor layer by simultaneously etching the plurality of overlapping sub-cavities into the semiconductor layer.

主权项

1. An apparatus comprising:
a semiconductor substrate; a dielectric stack formed over the semiconductor substrate, wherein the dielectric stack is a membrane; a first channel that extends through the dielectric stack; a second channel that extends through the dielectric stack and that is separated from the first channel; a first cavity that is formed in the semiconductor substrate by the introduction of an etchant through the first channel; and a second cavity that is formed in the semiconductor substrate by the introduction of an etchant through the second channel, wherein the first and second cavities overlap to at least partially form a composite cavity, wherein the first and second cavities are at least partially individually discernible sub-cavities, and wherein the composite cavity underlies at least a portion the dielectric stack.