Ohmic contacts to GaAs

The present capability of obtaining ohmic contacts to GaAs over a range of doping levels is reviewed. Possible models of transport across the metal-semiconductor interface are discussed and contact techniques are described. The widely used AuGe alloyed contact is seen to have a spatially inhomogeneous interface which appears to control its contact resistance. The most satisfactory process at this time is to alloy into a previously fabricated heavily doped layer. © 1983.