p-type doping of SiC by aluminum implantation for advanced device applications

6H-SiC epitaxial layers with a background n-type dopant concentration of 1×10¹⁶/cm³ were hot implanted to doses ranging from 4.0×10¹³ to 1.8×10¹⁴ Al ions/cm² at 65, 135, and 220 keV to achieve a box-type implant distribution to a depth of 300 nm. Electrical activation of dopants was carried out using a proximity annealing method at 1500 °C in a buffer environment to retard surface degradation of the SiC samples. Measurements using atomic force microscopy illustrated the morphological stability of the SiC surface during the high-temperature annealing. Transmission line measurements showed some degree of dopant activation. Characterization of fabricated p-n junction diodes demonstrated p-type conduction in the aluminum-implanted SiC samples.