InP based carbon-doped base HBT technology: its recent advances and circuit applications

Recent advances of carbon-doped InP/In/sub 0.53/Ga/sub 0.47/As singleand double-heterojunction bipolar transistor (SHBT and DHBT) technology, are reviewed. Chemical beam epitaxy (CBE) has been utilized to grow the device structures. Up to date, the SHBT having two 1.5 /spl mu/m/spl times/10 /spl mu/m emitter fingers has exhibited f/sub T/ and f/sub max(MAG/) of 186 GHz and 90 GHz, respectively. To our knowledge, the f/sub T/ of this device is the highest of any type of bipolar transistors yet reported. CW output power of 0.4 W (3.5 W/mm) with power-added efficiency of 36% has been achieved with the 12-finger DHBTs. The SMBT technology has been applied to realization of wideband amplifiers. A simple directly-coupled amplifier has shown a 3-dB bandwidth of over 20 GHz. The results indicate the great potential of carbon-doped base InP/InGaAs HBTs for high-speed and microwave applications. >