There is a growing demand for electronic signal processing at elevated
temperatures. A number of approaches have been used to develop this
capability. Silicon circuits could be developed and fabricated with an
appropriate technology to cover increased temperature ranges. In a
search for semiconductors with a wider energy gap to avoid leakage
currents at high operating temperatures, one developed compound
semiconductors such as GaAIAs on GaAs substrates. Efforts to use GaN are
also useful, although difficult due to the lack of a suitable substrate
material for lattice-matched epitaxial growth. Other work concerns
electronic compo- nent and circuit developments with SiC. Preliminary
results have proved interesting. This book attempts to present the
possibilities of such circuitry. Some of the solutions obtained so far
are directly usable for the many applications where high environmental
temperatures exist. Other concepts, particularly the more demanding
ones, such as operation above 500 °C, still need much more researching.
This also concerns estimates of device lifetimes for con- tinuous high
temperature operation. This book may help the potential user of such
circuitry to find a suitable solution. It should also stimulate more
research groups to enter this demanding effort. And finally, it should
stimulate a broad awareness of the need and the solutions for this type
of electronics. That is why Part One is devoted to high temperature
applications.
