DC and RF characteristics of 0.7-μm-gate-length diamond metal-insulator-semiconductor field effect transistor

A 0.7-mum-gate-length metal-insulator-semiconductor field effect transistor (MISFET) was fabricated on a hydrogen-terminated diamond surface conductive layer. The maximum transconductance of 100 mS/mm was obtained by DC measurement. The cutoff frequency of 11 GRz and the maximum frequency of oscillation of 18 GHz were achieved for the fabricated MISFET biased at V-GS = 0 V and V-DS = -12 V. These are the highest values for diamond MISFETs ever reported. In the MISFET, high-frequency small-signal equivalent circuit analysis is carried out at V-GS = 0 V and V-DS = -3, -5, -8, -10 and -12 V The analysis indicates that the reduction of parasitic resistance between the source and gate is necessary for realizing higher output power. (C) 2002 Elsevier Science B.V. All rights reserved.