High efficiency GalnAs/Inp heterojunction IMPATT diodes

Devices utilizing GaAs IMPATT diodes exhibit conversion efficiencies which are greater than 30 percent in the X-band. De Jaeger and Salmer (1980) have studied heterojunction Ge/GaAs diodes. However, technological problems due to crystal mismatch were found to occur. In the present investigation, the proposal is made to employ a GaInAs/InP heterojunction IMPATT diode. GaInAs /InP heterojunctions can technologically be obtained with a good quality interface. The study of GaInAs/InP heterojunction IMPATT diodes must take into account particular physical phenomena which arise in connection with the employed heterojunctions and semiconductors. Parasitic current injections occur as a result of the generation-recombination process and tunneling. The effect of the saturation current is studied, taking into account efficiency variations for various structures. By adding a thin n-InP zone to the structure, the tunneling current can be reduced. This leads to improvement in efficiency.