Abstract-We have fabricated 1 kV 4H and 6H SiC Schottky diodes utilizing a metal-oxide overlap structure for electric field termination. This simple structure when used with a high barrier height metal such as Ni has consistently given us good yield of Schottky diodes with breakdown voltages in excess of 60% of the theoretically calculated value. This paper presents the design considerations, the fabrication procedure, and characterization results for these 1 kV Ni-SiC Schottky diodes. Comparison to similarly fabricated Pt-SiC Schottky diodes is reported. The Ni-SiC ohmic contact formation has been studied using Auger electron spectroscopy and X-ray diffraction. The characterization study includes measurements of current-voltage (I0V ) temperature and capacitance-voltage (C0V ) temperature characteristics. The high-temperature performance of these diodes has also been investigated. The diodes show good rectifying behavior with ON/OFF current ratios, ranging from 10 6 to 10 7 at 27 C and in excess of 10 6 up to 300 C.

High voltage Schottky diodes have been fabricated on 3C-Sic films grown on Si substrates. A Ni metallization process has been developed to fabricate both rectifying and ohmic contacts to Sic by controlling the postannealing temperature. A high voltage (>150V) breakdown has been obtained at room temperature from the Sic Schottky diode. The Ni-Sic Schottky junction shows a thermal resistance for temperatures as high as 600°C. This technology has good potential for monolithic integration of Sic high power devices and Si integrated circuits.

SiC/Si heterostructures have been patterned by reactive ion etching with CHF3/O2 to produce SiC-covered and Si-exposed regions with lateral dimensions of 2.5 to ∼500 μm. The patterned samples were then anodized in HF/ethanol solutions. Short anodization times (<3 min) result in selective-area UV-induced visible photoluminescence (PL), with a peak located at 650 nm, being observed at 25 °C from only the SiC-covered regions. The emission is generated by porous Si (PoSi) selectively formed under the SiC cap and transmitted through the wide band-gap SiC layer. Longer etching times result in nonselective PL.

Highly efficient red-emitting phosphors, CaAlSiN :Eu , were successfully prepared by the solid-state method using calcium cyanide (CaCN ) as the single calcium source. The influences of crystallization temperature, crystallization time, calcination mode and compounds ratio on the photoluminescent properties were investigated. The CaAlSiN :Eu phosphors were obtained with 1 mol% CaCN by a two-step calcination procedure at 900°C for 2 h and subsequently at 1600°C for 8 h. The CaAlSiN :Eu phosphors showed the strongest luminescent intensity at 660 nm when excited by 468 nm. With an increase in crystallization time, the maximum wavelength of the emission was shifted from 644 nm to 660 nm.