Temperature-dependent characteristics of an Al0.2Ga0.8As/In0.22Ga0.78As pseudomorphic double heterojunction modulation doped field-effect transistor with a GaAs/AlGaAs superlattice buffer layer

Abstract

The Al0.2Ga0.8As/In0.22Ga0.78As pseudomorphic double heterojunction modulation doped field-effect transistor with a superlattice GaAs/Al0.2Ga0.8As buffer layer has been successfully grown by a molecular beam epitaxy (MBE) system, and investigated its temperature-dependent characteristics. The use of a superlattice buffer layer improved the degradation of the device performance at elevated temperatures. For a 1.5×125 μm2 gate dimension, a voltage gain as high as 107 is found at 460 K. Besides, the shift in the threshold voltage is about 0.222 V from 300 to 460 K.