Patent ID: 11923470
Assignee: SENSORS UNLIMITED, INC.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 7:
8. A method comprising:
forming an assembly of layers including growing an InP cap layer epitaxially on an InGaAs absorption region layer, wherein the InGaAs absorption region layer is on an n-InP layer, and wherein an underlying substrate layer underlies the n-InP layer;
removing a portion of the InP cap layer by dry etching, wherein the n-InP layer is a contact layer for a back side illuminated detector;
removing a portion of the substrate layer by chemical/mechanical polishing;
further selectively wet etching of the substrate layer; and
dry etching a portion of the n-InP layer away down to a final thickness of 10 nm.