Modeling of current-voltage characteristics for strained and lattice matched HEMT's on InP substrate using a variational charge control model

A model for the calculation of the current-voltage characteristics of strained In/sub 0.52/Al/sub 0.48/As/In/sub x/Ga/sub 1-x/As on InP substrate High Electron Mobility Transistors (HEMT's), based on a variational charge control model, is presented. A polynomial fit of the two-dimensional electron gas (2DEG) density is used for the calculation of the current-voltage characteristics. The effect of strain is introduced into the 2DEG density versus gate voltage relation. Very good agreement between the calculated and measured I-V characteristics was obtained. In addition, our results show that, for an indium mole fraction of the In/sub x/Ga/sub 1-x/As channel in the range 0.53-0.60, increasing the indium mole fraction lowers the threshold voltage and hence increases the drain current at the same gate bias.<
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