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:
May. 03, 2011
Filed:
May. 28, 2007
Tsuyoshi Nakano, Sodegaura, JP;
Tsuyoshi Nakano, Sodegaura, JP;
Sumitomo Chemical Company, Limited, Tokyo, JP;
Abstract
There are provided a higher-performance compound semiconductor epitaxial substrate having improved electron mobility characteristics and its production method. The compound semiconductor epitaxial substrate includes a channel layer in which electrons travel and an epitaxial layer on each of a front side and a back side of the channel layer, wherein a total p-type carrier concentration A (/cm) per unit area in the epitaxial layer on the back side of the channel layer and a total p-type carrier concentration B (/cm) per unit area in the epitaxial layer on the front side of the channel layer satisfy the following expression (1):0<≦3.5  (1)wherein A=(a concentration of all p-type carriers in an active state due to an acceptor impurity contained in the epitaxial layer on the back side of the channel layer)×(a total thickness of the epitaxial layer on the back side), and B=(a concentration of all p-type carriers in an active state due to an acceptor impurity contained in the epitaxial layer on the front side of the channel layer)×(a total thickness of the epitaxial layer on the front side).