Low-leakage current and high-breakdown voltage GaAs-based heterostructure field-effect transistor with In0.5(Al0.66Ga0.34)0.5P Schottky layer

An In0.5(Al0.66Ga0.34)0.5P/GaAs heterostructure field-effect transistor has been fabricated by metal-organic chemical vapor deposition. A turn-on voltage as high as 3.2 V along with an extremely low gate reverse leakage current of 69 μA/mm at VGD=−40 V are achieved. In addition, it is found that the device can be operated with gate voltage up to 1.5 V without significant drain current compression. These characteristics are attributed to the use of high Schottky barrier height, high band gap of In0.5(Al0.66Ga0.34)0.5P Schottky layer, and to the large conduction-band discontinuity at the In0.5(Al0.66Ga0.34)0.5P/GaAs heterojunction.