This article reports the fabrication and characterization of metal–semiconductor high electron mobility transistors (MS-HEMT) and metal–oxidesemiconductor (MIS-HEMT) grown on the semi-insulating SiC substrates with 0° and 4°-off axis. For the MIS-HEMT, the HfO₂ film was used as the insulator deposited by atomic layer deposition. With a gate length of 2 μm, MS-HEMT and MIS-HEMT devices with 4°-off SiC substrates exhibit a drain saturation current density (J_DS,max) of 895 and 1016 mA/mm, the maximum transconductance (G_m,max) of 225 and 175 mS/mm, a cut-off frequency (f_T) of 8.1 and 9.4 GHz, and a maximum oscillation frequency (f_max) of 22 and 27.4 GHz, respectively, which are better than those with 0° SiC substrates. Furthermore, the devices with 4°-off substrate are verified with less interface states and buffer traps through the temperature-dependent and pulse current–voltage measurements.

本文报道了在半绝缘SiC衬底（偏移轴为0°和4°）处生长的金属半导体高电子迁移率晶体管（MS-HEMT）和金属氧化物半导体（MIS-HEMT）的制造和表征。对于MIS-HEMT，HfO ₂膜用作通过原子层沉积法沉积的绝缘体。栅极长度为2μm时，具有4°偏离SiC衬底的MS-HEMT和MIS-HEMT器件的漏极饱和电流密度（J _DS，max）为895和1016 mA / mm，最大跨导（G _m，最大）为225和175 mS / mm，截止频率（f _T）为8.1和9.4 GHz，最大振荡频率（f _max）分别为22 GHz和27.4 GHz，这比采用0°SiC衬底的情况更好。此外，通过与温度有关的和脉冲电流-电压测量，可以验证具有4°偏离衬底的设备具有较少的接口状态和缓冲阱的能力。