Gerald J Trombley

US Patent:

55942628, Jan 14, 1997

Filed:

Apr 7, 1995

Appl. No.:

8/418747

Inventors:

Hyong Y. Lee - Beavercreek OH
Belinda Johnson - Dayton OH
Rocky Reston - Beavercreek OH
Chris Ito - Colorado Springs CO
Gerald Trombley - Centerville OH
Charles Havasy - Beavercreek OH

Assignee:

The United States of America as represented by the Secretary of the Air
Force - Washington DC

International Classification:

H01L 310256
H01L 2920

US Classification:

257192

Abstract:

The incorporation of an aluminum arsenide (AlAs) buffer layer in a gallium arsenide (GaAs) field effect transistor (FET) structure is found to improve the overall device performance, particularly in the high temperature operating regime. Similar characteristics may be obtained from devices fabricated with an Al. sub. x Ga. sub. 1-x As 0. 2. ltoreq. x. ltoreq. 1 barrier layer. At temperatures greater than 250. degree. C. , the semi-insulating gallium arsenide substrate begins to conduct significant amounts of current. The highly resistive AlAs buffer layer limits this increased conduction, thus permitting device operation at temperatures where parasitic leakage currents would impede or prevent device operation. Devices fabricated with AlAs buffer layers exhibited lower drain parasitic leakage currents and showed improved output conductance characteristics at 350. degree. C. ambient temperature.

US Patent:

54119022, May 2, 1995

Filed:

Jun 6, 1994

Appl. No.:

8/254722

Inventors:

Hyong Y. Lee - Fairborn OH
Belinda Johnson - Dayton OH
Rocky Reston - Beavercreek OH
Chris Ito - Colorado Springs CO
Gerald Trombley - Centerville OH
Charles Havasy - Beavercreek OH

Assignee:

The United States of America as represented by the Secretary of the Air
Force - Washington DC

International Classification:

H01L 21338

US Classification:

437 40

Abstract:

The incorporation of an aluminum arsenide (AlAs) buffer layer in a gallium arsenide (GaAs) field effect transistor (FET) structure is found to improve the overall device performance, particularly in the high temperature operating regime. Similar characteristics may be obtained from devices fabricated with an Al. sub. x Ga. sub. 1-x As (0. 2. ltoreq. x. ltoreq. 1) barrier layer. At temperatures greater than 250. degree. C. , the semi-insulating gallium arsenide substrate begins to conduct significant amounts of current. The highly resistive AlAs buffer layer limits this increased conduction, thus permitting device operation at temperatures where parasitic leakage currents would impede or prevent device operation. Devices fabricated with AlAs buffer layers exhibited lower drain parasitic leakage currents and showed improved output conductance characteristics at 350. degree. C. ambient temperature.