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. 05, 2004
Filed:
Aug. 19, 2002
Kazuhiro Ito, Hinode, JP;
Shigehisa Tanaka, Kunitachi, JP;
Sumiko Fujisaki, Hachioji, JP;
Yasunobu Matsuoka, Hachioji, JP;
Takashi Toyonaka, Yokohama, JP;
Opnext Japan, Inc., Yokohama, JP;
Abstract
Reducing a dark current in a semiconductor photodetector provided with a second mesa including an regrown layer around a first mesa. An n-type buffer layer, a n-type multiplication layer, a p-type field control layer, a p-type absorption layer, a cap layer made of p-type InAlAs crystal, and a p-type contact layer are made to grow on a main surface of a n-type substrate. Thereafter the p-type contact layer, the p-type cap layer, the p-type absorption layer and the p-type field control layer are patterned to form a first mesa. Next, after making a p-type regrown layer selectively grow around the first mesa or by forming a groove in the regrow layer located in a vicinity of the p-type cap type during a step of the selective growth, the p-type cap layer containing Al and the regrow layer are separated owing to the groove such that no current path is formed between both layers.