NING Li-Na Zhi-Hong FENG Ying-Ming WANG Kai ZHANG Zhen FENG
材料科学技术（英）
Two-inch semi-insulating SiC bulk crystals with resistivity higher than 1×106 Ωcm were achieved by vanadium
doping during sublimation. Secondary-ion-mass-spectrometry (SIMS) was employed to determine the concen-
tration of impurities in the crystals, such as B, Al, V and N. These results indicated that the concentration of
nitrogen and aluminum kept on decreasing and the concentration of B and V was almost constant during the
whole growth. An inner crucible was used to control the exhausting of vanadium, which made the uniformity
of the high resistivity (>1×106 Ωcm) in the wafer up to 80%. High-performance AlGaN/GaN high-electron-
mobility-transistor (HEMT) materials and devices were grown and fabricated on semi-insulating 6H-SiC sub-
strates. The two-dimensional electron gas (2DEG) mobility at room-temperature was 1795 cm2/V•s. The
charge carrier concentration of the substrate determined by capacitance-voltage (C-V) test was 7.3×1015 Ωcm−3.
The device with a gate width of 1 mm exhibits a maximum output power of 5.5 W at 8 GHz, which proves
the semi-insulating property of the substrates indirectly.
关键词:
Silicon Carbide
,
半绝缘
,
钒掺杂
,
AlGaN/GaN HEMT
