A Large Barrier Height Schottky Contact between Amorphous Si–Ge–B and GaAs

Electrical properties of contacts between amorphous Si–Ge–B and GaAs are studied. A Schottky contact with a barrier height as large as 0.99 V has been realized. The barrier height can be varied by changing the composition of the amorphous films. Amorphous Si–Ge–B is applied to GaAs FETs as gate electrodes. A large saturated drain current of 900 µA/10 µm gate width has been realized. This value is 1.88 times as large as conventional normally-off GaAs MESFETs.