Novel HEMT structures using a strained InGaP Schottky layer

The authors propose a new structure for InGaAs/InAlAs high electron mobility transistors (HEMTs) using a strained InGaP Schottky contact layer to achieve selective wet gate recess etching and to improve reliability for thermal stress. Strained In_0.75Ga_0.25P grown on InAlAs has been revealed to have sufficient Schottky barrier height for use as a gate contact. InGaAs/InAlAs HEMTs using an In_0.75Ga_0.25P layer have been grown by metal-organic chemical vapor deposition and 1μm-gate devices have been fabricated. High selectivity in gate recess etching and higher reliability during thermal treatment have been demonstrated