High Temperature Implantation of Single Crystal Beta Silicon Carbide Thin Films

Abstract

ABSTRACTIons of aluminum, gallium and nitrogen were implanted into (100) oriented β-SiC thin films at temperatures of 623K, 823K and 1023K. Rutherford backscattering/ion channeling analyses revealed that implantation of any one of the ionic species at 623K resulted in only slight crystal lattice damage. In comparison, implantation conducted using the same dosimetry and energy at room temperature resulted in extensive lattice damage; in the case of gallium, amorphization occurred. The backscattered yield from samples implanted at 1023K was nearly that of a virgin aligned spectra. This in situ annealing effect did not, however, result in the complete electrical activation of implanted species. In order to increase the percent of electrical activation, samples were annealed at 1473K for 1800s following implantation. Differential capacitance-voltage, spreading resistance and sheet resistance measurements were made in order to electrically characterize these layers. These measurements indicated the activation of p-type and n-type species in samples implanted with aluminum or gallium and nitrogen, respectively. The authors have previously reported p-type formation in β-SiC implanted with aluminum at room temperature following a 2073K - 300s anneal. By heating to 1023K during implantation and annealing at 1473K after implantation, improved structural and electrical properties have been achieved.