Polycrystalline diamond field-effect transistors

Abstract

The first demonstration of field-effect transistors fabricated from polycrystalline diamond thin films is reported. Diamond thin films were deposited by a microwave plasma chemical vapor deposition technique. The surface roughness was removed by polishing using a SiO x chemical machining technique. Ion implantation was employed to form a B-doped conducting surface channel with an approximate carrier concentration of5 × 10 18cm −3. A low temperature deposition of SiO 2 was used to form the gate dielectric structure. Gate leakage currents were below 10 nA at 25 V. Although the channel did not reach the pinch-off condition, modulation of the channel conductance was observed.