Title :
Amorphous-Si emitter heterojunction UHF power transistors for handy transmitter
Author :
Wang, Yin-Sheng ; Zhang, X.M. ; Sheng, W.W. ; Wang, X.W.
Author_Institution :
Device Res. Lab., Nanjing Electron. Devices Inst., China
fDate :
5/1/1990 12:00:00 AM
Abstract :
A UHF silicon heterojunction bipolar power transistor with a heavily doped amorphous-silicon emitter is reported. The fabrication process utilized an improved glow discharge technique. The deposition rate of amorphous silicon is 0.3-0.4 AA/s, which is slower than that of conventional a-Si:H. The average carrier density in the amorphous-silicon film is estimated to be about 1.5*10/sup 19/ cm/sup -3/. The present device can deliver 4.0-W output power with 72% collector efficiency and 8.2-dB gain at 470 MHz for 9.0-V low supply voltage. These preliminary results make the use of n/sup +/ a-Si:H as a wide-bandgap emitter material for high-frequency and high-power heterojunction bipolar transistors (HBTs) very attractive.<>
Keywords :
amorphous semiconductors; glow discharges; heterojunction bipolar transistors; hydrogen; power transistors; silicon; 4.0 W; 470 MHz; 8.2 dB; Si:H; bipolar power transistor; carrier density; collector efficiency; deposition rate; fabrication process; glow discharge technique; heterojunction UHF power transistors; heterojunction bipolar transistors; wide-bandgap emitter material; Amorphous materials; Amorphous silicon; Bipolar transistors; Fabrication; Frequency; Heterojunctions; Microwave devices; Microwave transistors; Power transistors; Transmitters;
Journal_Title :
Electron Device Letters, IEEE
