High microwave power submicron gate transistors on indium phosphide

The design, fabrication, and characterization of submicron gate indium phosphide (InP) high microwave power metal-insulator-semiconductor field-effect transistors (MISFETs) were investigated for frequencies up to 26.5 GHz.; Because the InP surface substantially determines the electrical characteristics of InP MIS devices the effects of encapsulated rapid thermal annealing (RTA) in pure nitrogen or hydrogen on the chemical nature of the Si{dollar}sb3{dollar}N{dollar}sb4{dollar}-InP interface were examined using x-ray photoelectron spectroscopy (XPS). There was a component of the In 3d{dollar}sb{lcub}5/2{rcub}{dollar} peak consistent with In(OH){dollar}sb3{dollar}, InO-(OH), or InO{dollar}sb2{dollar} which increased after RTA. The N-H or N-N component of the N 1s peak decreased significantly after RTA.; Ion implanted one micron gate InP microwave power MISFETs were fabricated using silicon implants in semi-insulating InP and RTA at 700 C for 30 sec in pure nitrogen or hydrogen. The gate length achieved was 1.4 {dollar}mu{dollar}m. The drain-source spacing (L{dollar}sb{lcub}rm ds{rcub}{dollar}) was 5 {dollar}mu{dollar}m. Total gate widths up to 1.0 mm were examined. At 9.7 GHz output power densities up to 2.34 W/mm were obtained, with a gain of 3.7 dB and power-added efficiency of 29%. The output power density is 70% higher than reported for GaAs power MESFETs.; Based on the results from the one micron gate InP MISFETs, submicron gate InP MISFETs were designed for improved output power density above 10 GHz. The submicron gate InP MISFETs were fabricated using an epitaxial layer on semi-insulating InP. A gate length of 0.7 {dollar}mu{dollar}m was achieved. Total gate widths from 0.2 to 1.0 mm were available. Submicron gate MISFETs were made with drain-source spacings of 2, 3, or 5 {dollar}mu{dollar}m. The output power density was best for L{dollar}sb{lcub}rm ds{rcub}{dollar}= 3 {dollar}mu{dollar}m. At 18 GHz 1.59 W/mm was obtained with a grain of 3.47 dB and power-added efficiency of 20.0%. At 20 GHz 1.20 W/mm was obtained with a gain of 3.17 dB and power-added efficiency of 13.6%. The output power density is 270% more than previously measured for InP MISFETs at 18 and 20 GHz, and 50% more than recently reported for pseudomorphic HEMTs at 20 GHz. The gain varied less than 3.0% over 12 hours.