Growth of high performance InGaAs InP doped channel heterojunction field effect transistor with a strained GaInP Schottky barrier enhancement layer by gas source molecular beam epitaxy

In this article, we present a systematic investigation of the Schottky char acteristics of metal/Ga0.2In0.8P/InP. It is found that barrier heights of 0 .6-0.7 eV are achieved for Schottky junctions formed on Ga0.2In0.8P/InP. Fe rmi level pinning occurs at the surface of the wet-etched Ga0.2In0.8P prior to metallization. No degradation in the Schottky characteristics is observ ed at temperatures as high as 250 degrees C. InGaAs/InP doped channel heter ojunction field-effect transistors (HFETs) with a Ga0.2In0.8P Schottky barr ier enhancement layer (SBEL) were grown and fabricated. The 0.25 mu m gate- length devices show excellent de and rf performance, with an f(t) of 117 GH z and an f(max) of 168 GHz. These results suggest that GaInP is a promising material as a gate SBEL for InP based HFET applications. (C) 1999 American Vacuum Society. [S0734-211X(99)06603-2].