We investigated the frequency dispersion in drain conductance of 0.1-μm-gate InAlAs/InGaAs high-electron mobility transisters under various bias conditions in a frequency range from 9 kHz to 500 MHz using a network analyzer. The substrate current was monitored from the backside of the wafer as a measure of the impact ionization rate. The relationship between the frequency dispersion and the impact ionization is explained quite well by the model we employed here. According to the model, the extrinsic transconductance of the device is the main factor governing the frequency dispersion of the drain conductance.
- Drain conductance
- Frequency dispersion
- Impact ionization
- Optical communication systems
- Substrate current