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:
Jun. 17, 2014
Filed:
Jan. 20, 2012
Tadao Ishibashi, Yokohama, JP;
Seigo Ando, Yokohama, JP;
Yoshifumi Muramoto, Musashino, JP;
Toshihide Yoshimatsu, Musashino, JP;
Haruki Yokoyama, Musashino, JP;
Tadao Ishibashi, Yokohama, JP;
Seigo Ando, Yokohama, JP;
Yoshifumi Muramoto, Musashino, JP;
Toshihide Yoshimatsu, Musashino, JP;
Haruki Yokoyama, Musashino, JP;
NTT Electronics Corporation, Kanagawa, JP;
Nippon Telegraph and Telephone Corporation, Chiyoda-Ku, JP;
Abstract
A layer in which the potential level difference normally unrequired for device operation is generated is positively inserted in a device structure. The potential level difference has such a function that even if a semiconductor having a small bandgap is exposed on a mesa side surface, a potential drop amount of the portion is suppressed, and a leakage current inconvenient for device operation can be reduced. This effect can be commonly obtained for a heterostructure bipolar transistor, a photodiode, an electroabsorption modulator, and so on. In the photodiode, since the leakage current is alleviated, the device size can be reduced, so that in addition to improvement of operating speed with a reduction in series resistance, it is advantageous that the device can be densely disposed in an array.