Title :
Integrated AlGaAs/GaAs HBT high speed operational amplifier
Author :
Dong Yi ; Zeng Qingming ; Cai Keli ; Zhang Keqiang
Author_Institution :
Hebei Semicond. Res. Inst., China
Abstract :
We report the fabrication and testing of a wideband and high slew-rate voltage-mode operational amplifier using AlGaAs/GaAs HBTs. The fabrication process showed that a higher carbon doping concentration is more effective to reducing base resistance and gives a good steadiness of process. The specific contact resistivity of base measured by TLM was 6.4/spl times/10/sup -7/ /spl Omega/.cm/sup 2/ at the base doping concentration 4/spl times/10/sup 19/ cm/sup 3/ by using a AuZu/Au alloy. The HBT operational amplifier has provided 500 v//spl mu/s high slew-rate, only 8 ns settling time and about 2 GHz unity-gain frequency. The circuit structure gave CMRR values in the order of 70 dB.
Keywords :
III-V semiconductors; aluminium compounds; bipolar analogue integrated circuits; gallium arsenide; heterojunction bipolar transistors; integrated circuit testing; operational amplifiers; transmission line matrix methods; wideband amplifiers; 8 ns; AlGaAs-GaAs; CMRR values; HBT high speed operational amplifier; TLM; base resistance; doping concentration; high slew-rate voltage-mode op amp; settling time; specific contact resistivity; unity-gain frequency; Broadband amplifiers; Conductivity; Doping; Electrical resistance measurement; Fabrication; Gallium arsenide; Heterojunction bipolar transistors; Operational amplifiers; Testing; Voltage;
Conference_Titel :
Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 1994. Technical Digest 1994., 16th Annual
Conference_Location :
Phildelphia, PA, USA
Print_ISBN :
0-7803-1975-3
DOI :
10.1109/GAAS.1994.636991
