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:
May. 23, 1995
Filed:
Jun. 25, 1993
Keiji Mita, Osaka, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
An optical semiconductor includes a photo diode integrated with a transistor built on first and second epitaxial layers grown of intrinsic material on a lightly doped substrate. A separating area divides the optical semiconductor into first and second isolated islands. The separating area is made up of a three separating areas, united end to end to form a single separating area. The first separating area is diffused at least upward from an interface between the substrate and the first epitaxial area. The second separating area is diffused both downward and upward from an interface between the first and second epitaxial layers. The third separating area is diffused downward from the surface of the second epitaxial layer into the substrate. The photo diode is formed in the first island area, and the transistor is formed in the second island area. An offsetting layer in the surface of the substrate, at least below the first island, is counterdoped to expand the depth of the depletion layer of the photo diode. The separating area extends into the substrate to a depth exceeding to the depth of the counterdoped region.