A gallium arsenide power rectifier

In this paper we will describe the fabrication of a gallium arsenide rectifier with a 10 ampere forward current capability, and reverse breakdowns of 40-100 volts. These units are fabricated by a manganese diffusion into gallium arsenide having a prediffusion carrier concentration of about /cm³. The diffusion techniques and evaluation will be described. Problems of conversion toward p-type will be reviewed. The details of mounting rectifiers for 400°C operation will be described including a review of possible brazing alloys. An acceptable technique for 400°C operation uses a newly developed gold-silver-germanium alloy as the bulk n-type contact. The contact to the mesa p-type side is more difficult to form. Heavy nickel plating and the same solder give a satisfactory solution. Operation at 400°C limits case material selection; typical ceramic insulated design is briefly described. The electrical characteristics of the diodes are discussed showing the effects of ambient temperatures on both forward and reverse current-voltage relationships.