Undoped InP/InGaAs heterostructure insulated-gate FET's grown by OMVPE with PECVD-deposited SiO/sub 2/ as gate insulator

The fabrication and performance of InP/InGaAs insulated-gate FETs which use a heterojunction to isolate the channel electrons from the semiconductor-insulator interface are discussed. Plasma-enhanced chemical vapor deposition (PECVD) was used to deposit SiO/sub 2/ on InP to form the gate insulator. Since the device structure is undoped, channel electrons are accumulated by the gate-induced field across the insulator. Extrinsic transconductances of 130 mS/mm (300 K) and 210 mS/mm (77 K) were achieved for 1.5- mu m gate-length devices. Gate-drain breakdown voltages in excess of 20 V were also measured.<
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