Development of high‐frequency SiC‐MESFETs

Abstract

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

Model and analysis of drain induced barrier lowering effect for 4H-SiC metal semiconductor field effect transistor

“…The simulated results also are comparable with the results presented in Refs. [14] and [15]. Also, the threshold voltage shift with different L/a ratio and different channel doping concentrations are presented in Fig.…”

Vanadium doping using VCl4 source during the chloro-carbon epitaxial growth of 4H-SiC

“…Therefore, many applications could benefit from epitaxial growth of SI SiC, to produce SI films of various thicknesses on top of much cheaper heavily doped n-type substrates, making it less expensive for use in RF device fabrication. This could also suppress deterioration of the thermal conductivity caused by deep-level impurities in the substrate [19,20]. Additionally, the ease of achieving low concentrations of donors and acceptors in epitaxial SiC makes it possible to achieve semi-insulating properties with very low-vanadium concentrations.…”

“…Parasitic gate effects, such as hysteresis in the drain-source current, in high frequency SiC devices were also attributed to the presence of V-related deep levels [18][19][20][21]. While HPSI substrates offered a promise of eliminating the parasitic effects caused by high V doping, the difficulty to achieve reproducible concentration of deep levels limited the adoption of the HPSI method for commercial device applications.…”

FLR Geometry Dependence of Breakdown Voltage Characteristics for JBS-Assisted FLR SiC-SBD

“…Silicon carbide (SiC) semiconductor material, which offers a wide band-gap (~3.26 eV), a high breakdown electric field (~4×10 6 V/cm), high thermal conductivity (~0.33 W/°C), high electron saturation velocity (~2.7×10 7 cm/s), and stable chemical bonding, has attracted considerable attention for application to future optoelectronic devices [1,2]. The high breakdown electric field enables realization of high power devices with a thinner and more heavily doped voltage blocking layer [3,4]. As a result, lightweight, compact, low cost devices that do not suffer from performance degradation can be realized.…”