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:
Nov. 11, 1997
Filed:
Dec. 06, 1995
Applicant:
Inventors:
Tatsuya Ohori, Kawasaki, JP;
Kanae Fukuzawa, Kawasaki, JP;
Assignee:
Fujitsu, Ltd., Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
257192 ; 257347 ;
Abstract
E and D mode HEMTs are integrated in a laminated layer of pairs of GaAs/AlGaAs layers formed on the same GaAs-on-Si substrate. The gate electrodes of E and D mode HEMTs are formed on different GaAs layers. The GaAs layer on Si contains crystal defects. It is hypothesized that the defects extend upward in the laminated layer of pairs of GaAs/AlGaAs layers formed on the GaAs layer with such crystal defects. Etch pits are generated as the AlGaAs layer is etched by ammonium etchant. Generation of etch pits can be suppressed by etching the whole part of the exposed AlGaAs layer and exposing the GaAs layer under the gate electrode.