GAINP/GAAS HBTS FOR HIGH-SPEED INTEGRATED-CIRCUIT APPLICATIONS

We report the demonstration of using GaInP/GaAs HBT's for integrated circuit applications. The fabricated discrete devices showed excellent dc characteristics with low V(ce) offset voltage and very low temperature sensitivity of the current gain. For a non-self-aligned device with 3 x 1.4 mum x 8.5 mum emitter area, the f(T) was extrapolated to 45 GHz and f(max) was extrapolated to 70 GHz. More importantly, the measured I/f noise level was 20 dB better than that of AlGaAs HBT's and comparable to that of low-noise silicon bipolar junction transistors, and the noise bump (''Lorentzian component'') was not observed. The fabricated gain block circuits showed 8.5 dB gain with a 3-dB bandwidth of 12 GHz, and static frequency dividers (divide by 4) were operable up to 8 GHz.