Wide bandgap semiconductor materials for high temperature electronics

High temperature electronics is an advancing held aimed at the development of semiconductor devices designed to function reliably at temperatures in e xcess of 125 degrees C. Already conventional semiconductor materials like s ilicon or gallium arsenide are capable of operating to 300-400 degrees C us ing 'temperature hardening' modifications in design and associated material s such as metallisation schemes. Despite this progress a significant body o f research has been focused towards the development of wide bandgap semicon ductor materials. These are semiconductors with bandgaps larger than those of Si (1.1 eV) and GaAs (1.43 eV) and include silicon carbide (3C 2.39 eV, 6H 3.02 eV); the III-nitride (In-y, Al1-y)(x)Ga1-x N alloys (0 less than or equal to x, y less than or equal to 1) with band gaps ranging from 1.9-6.2 eV; and diamond (5.45 eV). The wider bandgap potentially offers higher ope rating temperatures before the thermally activated intrinsic carrier curren t causes latch up. This paper reviews the current status of wide bandgap se miconductor material growth and semiconductor doping. Examples of high temp erature devices fabricated from these materials, their processing and elect rical characteristics are discussed. (C) 1999 Elsevier Science S.A. All rig hts reserved.