US Patent 7745853 Multi-layer structure with a transparent gate

A multi-layer structure with a transparent gate includes a MHEMT device structure comprising a GaAs substrate, a Schottky layer and a cap layer formed on the Schottky layer; a transparent gate formed on the Schottky layer being an indium tin oxide, ITO; and a drain and a source formed on the cap layer. Moreover, the MHEMT device structure includes a graded buffer, a buffer layer, a first spacer layer, a channel layer, and a second spacer layer formed between the GaAs substrate and the Schottky layer in a stacked fashion. The multi-layer structure is a transparent gate HEMT employing indium tin oxide which can make HEMT more sensitive to the light wave.