Metal-semiconductor field-effect transistors were fabricated on epitaxial layers grown onto (00•1)Si faces by chemical vapor deposition, and the influence of screw dislocations in the epitaxial layers was studied. The fabricated MESFETs, with a gate-length of 1µm, indicated a maximum transconductance of 30 to 35mS/mm for a drain-source saturation current of 30 to 40mA/mm. The evaluation of small-signal radio-frequency characteristics revealed a cut-off frequency of 2.7GHz and a maximum operational frequency of 6.8GHz. The direct-current characteristics of MESFETs with screw dislocations in the device channel region were compared with those of MESFETs without such dislocations. This comparison demonstrated for the first time that the drain-source current-voltage characteristics of MESFETs were negligibly affected by screw dislocations, although they caused some degradation of the gate Schottky characteristics.

Influence of Screw Dislocations on DC Characteristics of 6H-SiC Metal-Semiconductor Field-Effect Transistors. T.Aigo, M.Katsuno, T.Fujimoto, H.Yashiro, N.Ohtani: Japanese Journal of Applied Physics - 1, 2002, 41[5A], 2855-8