Excellent uniformity in the threshold voltage, transconductance, and current-gain cutoff frequency of InAlAs / InGaAs / InP MODFET's has been achieved using a selective wet gate recess process. An etch rate ratio of 25 was achieved for InGaAs over InAlAs using a 1:1 citric acid:H2O2 solution. By using this solution for gate recessing, we have achieved a threshold voltage standard deviation of 15 mV and a transconductance standard deviation of 15 mS / mm for devices across a quarter of a 2-in-diameter wafer. The average threshold voltage, transconductance, and current-gain cutoff frequency of 1.0-μ.m gate-length devices were -234 mV, 355 mS / mm, and 32 GHz, respectively.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering