Continued Development and Characterization of Doped Layers, Contacts and Associated Electronic Devices in Silicon Carbide

Abstract

Abstract : Electronic devices for microwave applications, the science and technology of ohmic and Schottky contacts and equipment fabrication for ultra- high purity thin films have been the subjects of concern for the application of growth of the 6H SiC polytype in this reporting period. MESFETs having gate lengths of 2, 4, 13 and 24 microns with maximum transconductances in the range of 1.5-22 ms/mm, respectively and with very low subthreshold leakage currents were fabricated. The 2 micron device also had threshold frequency of 510 MHz at OdB gain; the power gain crossed OdB at approximately 380 MHz. IMPATT based on Schottky diodes showed permanent breakdown; those based on p-n junctions appear promising. Ohmic and Schottky contacts are important for devices; thus, a program to examine the interface chemistry and associated electrical properties of high purity contacts deposited under controlled conditions, have been initiated. A molecular beam epitaxy system for the deposition of high purity SiC films is also nearing completion. Keywords: Silicon carbide, Ohmic contacts, Schottky contacts, Molecular beam epitaxy.