4H-SiC lateral double implanted metal-oxide-semiconductor field effect transistors (LDIMOSFET) were fabricated on on-axis semi-insulating SiC substrates without using an epi-layer. The LDIMOSFET adopted a current path layer (CPL), which was formed by ion-implantation. The CPL works as a drift region between gate and drain. By using on-axis semi-insulating substrate and optimized CPL parameters, breakdown voltage (BV) of 1093 V and specific on-resistance (R on,sp) of 89.8 mΩ&cm 2 were obtained in devices with 20 µm long CPL. Experimentally extracted field-effect channel mobility was 21.7 cm 2 &V %1 &s %1 and the figure-of-merit (BV 2 /R on,sp) was 13.3 MW/cm 2 .

SiC dry etching process for formation of a trenched-gate structure in trench metal-oxide-semiconductor field-effect-transistors employing bottom protection p-well (BPW) has been investigated. SF ₆ /O ₂ /Ar based inductively-coupled-plasma reactive-ion-etching were utilized with various variations in process parameters, such as bias power, ICP power, kind of gas species, working pressure and temperature. The effects of process parameters on trench profiles were analyzed by a cross-sectional scanning electron microscope and profilometer to suppress micro trenches at a bottom corner of the trench and improve SiC/SiO ₂ etch selectivity. We successfully demonstrated the micro-trench free SiC trench structure with high SiC/SiO ₂ etch selectivity of 3.7 at bias power of 1 kW, ICP power of 4 kW, SF ₆ /O ₂ /Ar flows of 6/6/8 sccm, working pressure of 15 mTorr and temperature of 20 °C.

TID effects occur in MOS-gated transistors in radiation environments where proton and gamma-rays irradiate the devices. TID effects seriously affect the electrical characteristics of Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). They can eventually result in the malfunction of power systems when exposed to long-term radiation conditions. We irradiated gamma-rays and protons into 1.2 kV SiC MOSFETs and evaluated the change in electrical properties to analyze the TID’s effects. As a result of the experiment, the threshold voltage (V_T) and on-resistance (R_on) of 1.2 kV SiC MOSFETs decreased because positive fixed charges inside the oxide increased depending on the radiation dose of the gamma-ray and fluence of the proton irradiations. The degradation of breakdown voltage (BV) occurred owing to a change in the depletion curvature at the edge of termination regions owing to the trapping of the charge in the field’s oxide.

The forward current–voltage characteristics of p-type diamond pseudo-vertical Schottky barrier diodes are investigated via numerical simulation. Impact ionization decrease the hole concentration of the p− drift layer from 10 ¹⁵ to 10 ¹⁴ cm ^–3 at 300 K, thereby increasing the forward voltage drop and on-resistance. When we consider an incomplete ionization with increasing temperature, the increase in the hole concentration is more dominant than the enhanced phonon scattering, thereby resulting in an increasing forward current. We modified the Ohmic contact for both metallic conduction at the p+ layer and incomplete ionization at the p– drift layer. The Baliga figure-of-merit of the device with and without incomplete ionization is 25 and 192 MW cm ⁻² , respectively. Incomplete ionization should be considered in the numerical study of diamond power devices.