Thermal stability of strained AlGaAs/InxGa1-xAs (0.15 less than or equal to x less than or equal to 0.25) doped-channel structures was evaluated for different In contents after a high temperature process. Strained channels may be relaxed after heat treatment resulting in carrier decrease, sheet resistance increase, and layers becoming more light sensitive. This degradation is more profound for high In content doped-channel films. Doped-channel FET characteristics confirm this conclusion, and low-fequency noise spectra indicate the existence of traps in the thermally treated devices.
