1/f noise characteristics of InP/InGaAs heterojunction bipolar transistors

The short-circuit noise characteristics of InGaAs/InP HBTs (heterojunction bipolar transistors) have been characterized in terms of frequency, bias, geometry, and temperature. Frequency dependence characteristics showed essentially 1/f noise behavior for both the collector noise spectra, S/sub IC/(f), and the base noise spectra, S/sub 1B/(f). A decrease was observed at high frequencies which was determined to be due to shallow traps with activation energy=0.07-0.1 eV. Extrapolated results estimate that the transition frequency could be as high as 100 MHz. S/sub IB/ is probably due to recombination noise. The origin of S/sub IC/ is not clear, but at low bias it seems to be due to recombination. Geometry studies revealed that the perimeter to area ratio does not have a significant effect on InP-based HBT noise. Preliminary emitter area studies have shown that the S/sub IC/ is a function of emitter area at low J/sub C/.<
>