Long-term effects of sidegating on GaAs MESFETs

Author

Cholan, Hema ; Stunkard, Douglas ; Rubalcava, Tony

Author_Institution

TriQuint Semiconductor Inc., Beaverton, OR, USA

fYear

1992

fDate

March 31 1992-April 2 1992

Firstpage

49

Lastpage

53

Abstract

The main purpose of this study was to monitor the effects of sidegating over time. Both enhancement mode and depletion mode MESFETs, with and without isolation implants, were tested at elevated temperatures. The sidegate effect is caused when carriers are introduced into the substrate with a negative potential contact. All electrodes were manufactured with ohmic contacts. Once in the substrate, the electrons move towards more positive potentials. As they move through the GaAs substrate, some electrons are trapped. If trapped near the FET, the electrons can influence the threshold or pinchoff voltage of the device. In this study, the influence was measured by monitoring the channel current in MESFETs. A FET was considered sidegated, when the channel current was reduced by 10%. This study was performed also to investigate whether the wearout failure mechanisms make MESFETs more susceptible to sidegating effects as they age.<>

Keywords

III-V semiconductors; Schottky gate field effect transistors; electron traps; failure analysis; gallium arsenide; semiconductor device testing; GaAs; GaAs substrate; channel current; depletion mode MESFETs; electron trapping; enhancement mode MESFET; isolation implants; long term effects; negative potential contact; ohmic contacts; pinchoff voltage; sidegating; threshold voltage; wearout failure mechanisms; Electrodes; Electron traps; FETs; Gallium arsenide; Implants; MESFETs; Manufacturing; Monitoring; Temperature; Testing;

fLanguage

English

Publisher

ieee

Conference_Titel

Reliability Physics Symposium 1992. 30th Annual Proceedings., International

Conference_Location

San Diego, CA, USA

Print_ISBN

0-7803-0473-X

Type

conf

DOI

10.1109/RELPHY.1992.187621

Filename

187621