Silicon carbide (SiC) MESFETs-with gate lengths from 0.3 µm to 1.5 µm-were fabricated on a semi-insulating substrate, and their RF characteristics were measured. These measurements showed that when the gate length is less than 1.0 µm, the cutoff frequency f t and maximum oscillation frequency f max of the SiC-MESFETs is less dependent on gate length. It was also found that the degradation of these RF characteristics is apparently caused by the short-channel effect. To uncover the mechanism underlying this finding, static electrical characteristics, such as the transconductance and threshold voltage of the fabricated short-channel SiC-MESFETs, were investigated; consequently, it was found that the short-channel effect occurred when the aspect ratio of gate length to channel thickness was five or less.

We have developed high power SiC-MESFETs for high-freqeuncy applications. We obtained a cutoff freqeuncy of 9.3 GHz and a maximum oscillation frequency of 34.2 GHz from a 0.5 µm gate MESFET. We measured pulsed output power characteristics of 54.1 W at 1.0 GHz and 11.2 W at 9.4 GHz from a 39.2mm-gate-MESFET and a 9.6mm-gate-width MESFET, respectivly. SiCMESFET

No abstract

No abstract

No abstract