Papers by Keyword: f_t

Abstract: We fabricated a 0.5-μm-gate MESFET on a bulk 4H-SiC semi-insulating substrate using ion implantation for the channel and contact regions. Our device design used a thin, highly doped channel layer, which was implanted at single energy to improve the device’s RF characteristics. The electrical characteristics of the ion-implanted MESFET annealed at 1700°C were better than those of the ion-implanted MESFET annealed at 1300°C. The fabricated ion-implanted MESFET has a maximum transconductance of 32.8 mS/mm and an fT/fmax of 9.1/26.2 GHz. The saturated output power was 26.2 dBm (2.1 W/mm) at 2 GHz. These values were the same as those of the conventional epitaxial MESFET with a recessed gate.

Abstract: We fabricated a 0.5-μm gate MESFET on a bulk semi-insulating 4H-SiC substrate by using ion implantation for the channel layer and contact region. Nitrogen ions were implanted to obtain a 0.25-μm-thick box-shaped profile with a doping density of 3.0×1017/cm3 for the channel region and to obtain a 0.2-μm-thick box-shaped profile with a doping density of 2.0×1020/cm3 for the contact region. Activation annealing is done in argon ambient at 1300 °C for 30 minutes. A 0.5- μm gate MESFET with 100-μm gate width showed a cut-off frequency of 7.5 GHz and a maximum oscillation frequency of 22.2 GHz. And its saturated output power was 25 dBm (3.16 W/mm), power gain was 6.7 dB and PAE was 15.7%.