Recent advances in InP-based HEMT/HBT device technology

Recent advances in InP-based HEMT/HBT (high electron mobility transistor/heterojunction bipolar transistor) device technology are reviewed. It is pointed out that, while the potential superiority of the InP-based heterostructure devices in high-speed and low-noise performances over GaAs devices has been verified, problems that are mainly related to the narrow bandgap of InGaAs are still left to be solved. Low breakdown voltages and kink effects in I-V characteristics are common problems in these devices. Device isolation for InP-based HBTs also needs improvement. It is expected, however, that with progress in crystal growth technologies, these problems will largely be solved in the near future, for instance, by the incorporation of InP or InGaAsP active layers. The reliability problem is also considered. Since the reliability data are too scarce, studies on this subject must be performed more intensively for the practical use of InP-based HEMTs and HBTs.<>