Abstract

Metal-oxide-semiconductor field-effect transistors (FETs) have been fabricated using B-doped diamond thin films deposited on (100) highly-oriented polycrystalline diamond (HOD) and single crystal insulating diamond substrates. The HOD material has properties superior to randomly-oriented polycrystalline diamond and offers a viable alternative to large area single crystal diamond. Concentric-ring FETs were fabricated using standard optical lithography and silicon dioxide was used as the gate dielectric. Diamond FETs exhibited well-behaved pinch-off and saturation of the channel current at temperatures up to 325°C for both HOD and single crystal diamond devices. Single crystal devices have been characterized in both enhancement and depletion-mode at elevated temperatures in excess of 500°C. Single crystal devices have been biased in common source amplifier configurations and NAND and NOR digital logic circuits. The behavior of field-effect transistors fabricated on HOD and single crystal diamond films, as well as diamond transistor circuits will be presented.

© 1995 Optical Society of America