The Status of Transistor Research in Compound Semiconductors

New semiconductors capable of competing with germanium and silicon in transistor applications must be looked for among the compound semiconductors, and more specifically among the III-V and IV-IV compounds. Gallium arsenide and indium phosphide are the most promising all-round materials for high-frequency as well as high-temperature performance. Indium antimonide and indium arsenide may be of interest for extremely high-frequency transistors operating at low temperatures The aluminum compounds, gallium phosphide and silicon carbide, are potentially useful for very high operating temperatures at the cost of high-frequency performance. Some of the unusual properties of the compound semiconductors have led to novel methods of junction preparation and new junction structures, such as the surface-diffusion and the widegap junction. Bipolar and unipolar surface-diffusion transistors have been demonstrated in indium phosphide, and the wide-gap emitter principle for high injection efficiency has been experimentally verified in gallium arsenide transistors. Electron lifetimes in these two compound semiconductors are estimated from the transistor results.