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:
Aug. 05, 1997
Filed:
Nov. 14, 1995
Motohiro Suyama, Hamamatsu, JP;
Masaharu Muramatsu, Hamamatsu, JP;
Makoto Oishi, Hamamatsu, JP;
Yoshitaka Ishikawa, Hamamatsu, JP;
Koei Yamamoto, Hamamatsu, JP;
Hamamatsu Photonics K.K., Hamamatsu, JP;
Abstract
In a photomultiplier of the present invention, a semiconductor device arranged in an envelope to oppose a photocathode is constituted by a semiconductor substrate of a first conductivity type, a carrier multiplication layer of a second conductivity type different from the first conductivity type, which is formed on the semiconductor substrate by opitaxial growth, a breakdown voltage control layer of the second conductivity type, which is formed on the carrier multiplication layer and has a dopant concentration higher than that of the carrier multiplication layer, a first insulating layer formed on the breakdown voltage control layer and said carrier multiplication layer while partially exposing the surface of the breakdown voltage control layer as a receptor for photoelectrons and consisting of a nitride, and an ohmic electrode layer formed on a peripheral surface portion of the receptor of the breakdown voltage control layer. When the dopant concentration distribution in the carrier multiplication layer is uniformly controlled on the basis of epitaxial growth, the uniformity of an avalanche multiplication gain for photoelectrons incident at different positions on the receptor of the semiconductor device is improved, thereby largely increasing the energy resolving power.