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. 20, 2000
Filed:
Sep. 29, 1997
Applicant:
Inventor:
Hirokazu Oikawa, Tokyo, JP;
Assignee:
NEC Corporation, , JP;
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
257192 ; 257194 ; 257195 ; 438571 ; 438572 ;
Abstract
On a semiconductor substrate, a channel layer, an electron supply layer, a third semiconductor layer, a second etching stopper layer, a second semiconductor layer and a first etching stopper layer and a first semiconductor layer are grown in sequential order to form E-type and D-type FETs. The third semiconductor layer and the second semiconductor layer have equal layer thickness, and the second etching stopper layer and the first etching stopper layer have the equal layer thickness. Thus, Vth of the E-type and D-type FETs can be controlled at the predetermined value with high reproduction ability.