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. 03, 2009
Filed:
Dec. 12, 2006
Yoshihiko Moriya, Hitachi, JP;
Yoshihiko Moriya, Hitachi, JP;
Hitachi Cable, Ltd., Tokyo, JP;
Abstract
A transistor epitaxial wafer having: a substrate; an n-type collector layer, a p-type base layer and an n-type emitter layer formed on the substrate in this order; and an n-type InGaAs non-alloy layer having an n-type InGaAs nonuniform composition layer formed on the n-type emitter layer and having an nonuniform indium (In) composition, and an n-type InGaAs uniform composition layer formed on the n-type InGaAs nonuniform composition layer and having a uniform indium (In) composition. The n-type InGaAs nonuniform composition layer has a first layer doped with Si and having a low indium (In) composition, and a second layer formed on the first layer, doped with an n-type dopant except Si, and having an indium (In) composition higher than the first layer.