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:
Oct. 01, 1985
Filed:
Nov. 18, 1982
Frederick Scholl, Bronx, NY (US);
Codenoll Technology Corporation, Yonkers, NY (US);
Abstract
A heterojunction photodiode with improved wavelength-selectivity and risetime. The problem of short-wavelength diffusion-tail response is avoided by interposing between the window and active layers a barrier layer of higher bandgap than that of the window layer, which prevents high-energy photocarriers generated in the window layer from diffusing to the PN junction. In one embodiment, n-type substrate, active, barrier, and window layers are initially grown, and the window layer is coated with an opaque oxide. A window is opened in the oxide layer, and a p-type dopant is diffused heavily through the opening, through the window layer, and partly into the barrier layer. A PN junction is thus formed in the barrier layer, its depletion region extending through the remaining n-type region of the barrier layer and into the active layer, where photocarriers are generated by photons passing through the window-opening.