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. 23, 1999
Filed:
Oct. 08, 1997
Tatsuya Kimura, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A light detecting device includes a first conductivity type semiconductor substrate; an insulating semiconductor window layer disposed on the substrate; a concavity in a region of the window layer and penetrating through the window layer; successively disposed in the concavity, a first conductivity type lower cladding layer, a first conductivity type guide layer of a semiconductor material having a band gap energy smaller that the band gap energies of the lower cladding layer and the window layer, an undoped light absorption layer having a band gap energy smaller than that of the first conductivity type guide layer, and a second conductivity type guide layer having a composition approximately identical to that of the first conductivity type guide layer, edges of the first conductivity type guide layer, the light absorption layer, and the second conductivity type guide layer being exposed at a surface of the window layer; and a layer of an insulating material, covering the edges. The interface between the window layer and the lower cladding layer is a regrowth interface and does not contact the absorption layer. The light detecting device has reduced dark current.