The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 01, 1994
Filed:
Feb. 12, 1992
Keizi Mita, Oizumimachi, JP;
Sanyo Electric Co., Ltd., Moriguchi, JP;
Abstract
An optical semiconductor includes a photo diode integrated with a transistor built on first and second epitaxial layers grown on a substrate, the first epitaxial layer is grown on the substrate from intrinsic material. The second epitaxial layer is grown doped on the first epitaxial layer. A separating area divides the optical semiconductor into first and second isolated islands. The separating area is made up of a lower separating area, a middle separating area and an upper separating area united to form a single separating area. The lower separating area is diffused at least upward from an interface between the substrate and the first epitaxial area. The middle separating area is diffused both downward and upward from an interface between the first and second epitaxial layers. The upper separating area is diffused downward from the surface of the second epitaxial layer. The photo diode is formed in the first island area, and the transistor is formed in the second island area. A counterdoped region in the surface of the substrate, at least below the first island, expands the depth of the depletion region of the photo diode. The separating area enters the substrate to a depth corresponding to the depth of the counterdoped region.