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. 15, 2011
Filed:
Nov. 07, 2008
Suguru Akiyama, Kawasaki, JP;
Suguru Akiyama, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A semiconductor device includes an InP substrate, an AlGaInAs-based first layer, an AlGaInAs-based second layer, an InGaAsP-based third layer, and an InGaAsP-based fourth layer. The first and second layers have compositions which are same or substantially same as each other on an interface therebetween. The composition of the layer varies such that a band gap continuously increases from the first layer side toward the third layer side. The compositions of the second and third layers are set such that energy levels of a valence band maximum are substantially equal to each other on an interface between the second and third layers. The composition of the third layer varies such that a band gap continuously increases from the second layer side toward the fourth layer side. The compositions of the third and fourth layers are same or substantially same as each other on an interface between the third and fourth layers.