Investigation of influence of DX centres on HEMT operation at room temperature

A study of DX centres in AlGaAs layers is presented, both experimental and theoretical. It is shown that owing to DX centres, at room temperature, the microwave transconductance of HEMTs can be considerably higher than that obtained from the DC regime, and approaches the values which could be expected if DX centres did not exist. As a result, for room temperature applications, special structures designed to eliminate DX centres are not really necessary.