Fabrication and characterization of aluminum/4hydrogen-silicon carbide Schottky diodes

SiC is a promising electronic material for high-power, high-frequency, and high-temperature applications. A lack of high-quality material growth technology and a sufficient understanding of SiC devices have slowed the commercial development of SiC devices. This research project focuses on the fabrication and characterization of 4H-SiC Schottky diodes, and can be divided into three parts. The first part was a study of the current conduction mechanism in Al/4H-SiC Schottky diodes, and was accomplished by examining the complete forward and reverse I–V characteristics. Experimental results showed that the charge transport mechanisms in the Al/4H-SiC Schottky diodes were: (1) Thermionic emission at a low forward voltage range, (2) Space-charge-limit current at a medium forward voltage range, and (3) Ohmic conduction due to series resistance at high forward bias. Modeling of the devices transport on the above mechanisms corresponded well with the experimental data at all ranges of temperature and voltage. The second part of this research dealt with the impact of micropipe defects. A comparison of the characteristics of the one diode with micropipe defects was made with the other diodes that had no defects. The third part of this research was to study the effects of different surface treatments on Al/4H-SiC Schottky diodes and Au/4H-SiC Schottky diodes.