Title :
Effects of alloying and bias stress on the base contacts of AlGaAs/GaAs HBTs
Author :
Sheng, H. ; Amin, F. ; Rezazadeh, A.A.
Author_Institution :
Dept. of Electron. & Electr. Eng., King´´s Coll., London, UK
Abstract :
The stability of AlGaAs/GaAs Heterojunction Bipolar Transistors (HBTs) with discretion to different base metal ohmic contact systems were studied by means of thermal alloying and current stress. The ohmic contacts studied were Au/Zn/Au and Ti/Au. It was found that after thermal alloying, though the Au/Zn/Au base contacts gave the lower base resistance, devices with Ti/Au contacts were more thermally reliable. With current stress, though alloyed Ti/Au devices gave a more reliable performance than Au/Zn/Au, they are still not optimum for long term device operation
Keywords :
III-V semiconductors; aluminium compounds; contact resistance; gallium arsenide; gold; heterojunction bipolar transistors; ohmic contacts; semiconductor device reliability; semiconductor-metal boundaries; stability; thermal stability; titanium; zinc; AlGaAs/GaAs HBTs; Au-Zn-Au; Au/Zn/Au contacts; GaAs-AlGaAs; Ti-Au; Ti/Au contacts; base contacts; base resistance; bias stress; current stress; metal ohmic contact systems; stability; thermal alloying; thermally reliability; Alloying; Contact resistance; Gallium arsenide; Gold; Heterojunction bipolar transistors; Ohmic contacts; Thermal resistance; Thermal stability; Thermal stresses; Zinc;
Conference_Titel :
High Performance Electron Devices for Microwave and Optoelectronic Applications Workshop, 1996. EDMO
Conference_Location :
Leeds
Print_ISBN :
0-7803-3130-3
DOI :
10.1109/EDMO.1996.575815
