High-speed enhancement mode InP MISFETs grown by Chloride vapor phase epitaxy

We report the properties of enhancement mode InP metal-insulator-semiconductor field-effect transistors fabricated on semi-insulating InP substrates. The epitaxial layers of the device structure have been grown by chloride vapor phase epitaxy. Short-circuit current gain cut-off frequencies of 29 GHz were measured for 1 µm gate length devices, close to a theoretical value of 40 GHz. For devices having submicron gate lengths extrinsic transconductance values up to 300 mS/mm were measured. We have successfully utilized SiO2deposited by electron beam evaporation, and plasma enhanced CVD Si3N4as gate insulators, with a drain current drift of 30 percent within the first 50 hours of operation. The high-speed performance of the MISFETs represent to our knowledge the fastest InP-based field-effect transistor ever demonstrated, and surpasses that of the state-of-the-art AlGaAs/GaAs modulation doped field-effect transistors having similar gate length.