Growth, fabrication, and device characterization of indium gallium arsenide channel gallium arsenide-based heterostructure field effect transistors.

摘要

A study of InGaAs channel heterostructure field effect transistors (HFETs) on GaAs substrates was undertaken utilizing the low pressure organometallic chemical vapor phase epitaxial (OMVPE) growth technique. Excellent quality HFET material properties were obtained for a split level donor structure, in which the Schottky gate was placed on an undoped AlGaAs layer grown on top of the doped AlGaAs donor layer. A one micron gate length fabrication process was developed to examine the device properties of these materials. A very strong correlation between material characterization results and device performance was observed in all cases.;After demonstrating the consistency of the growth and fabrication processes using an ;Critical layer thickness (CLT) issues were examined using ;A linear channel indium grading methodology was developed to delay the onset of misfit dislocations. Grading from 25-33% produced device properties commensurate with the ungraded 33% indium channel structure, without the asymmetry effects due to dislocation formation. Efforts at developing lattice constant engineered substrates were undertaken. Linear grading to 53% indium at a low growth temperature of 575