STUDIES ON THE PROSPECTS OF GAINAS AND GAINASP FOR DOUBLE-DRIFT REGION HETEROSTRUCTURE IMPATTS

Double heterojunctions having the material combinations InP/GaInAs/InP , GaAs/GaInAs/GaAs and InP/GaInAsP/InP have been studied to assess the ir potential for double-drift region (DDR) IMPATT diodes. An accurate and realistic computer simulation program has been framed and used for the de and high-frequency analysis of the DDRs. The analysis is carri ed out both in IMPATT (IMPact Avalanche Transit Time) and MITATT (MIxe d Tunnelling Avalanche Transit Time) modes. Our results indicate that the GaAs/GaInAs/GaAs DDR would provide the best mm-wave performance up to sufficiently high frequencies. Further, the performance of the DDR diodes is observed to deteriorate at high frequency of operation due to phase distortion introduced by tunnel injected current, which is fo und to be the least in the case of GaAs/GaInAs/GaAs DDR leading to the best performance of this DDR amongst the three.