Epitaxial growth and doping of and device development in monocyrstalline β-SiC semiconductor thin films

Abstract

High-purity monocrystalline β-SiC films have been chemically deposited on Si(100) and α-SiC(0001) at 1660–1823 K and 0.1 MPa using SiH 4 and C 2H 4 carried in hydrogen. Films grown on the on-axis Si(100) contained substantial concentrations of dislocations, stacking faults and antiphase boundaries; those deposited on α-SiC(0001) contained primarily double positioning boundaries. These boundaries were eliminated by using off-axis orientations of the respective substrates. Films produced on Si(100) have also been doped via ion implantation with boron or aluminum (p-type) or phosphoruus or nitrogen (n-type) at liquid nitrogen, room and elevated temperatures. High-temperature ion implantation coupled with dynamic and post annealing resulted in a markedly reduced defect and precipitate concentration relative to that observed in similar research at the lower temperatures. The current-voltage characteristics of the MESFETs measured from 298 to 623 K indicated reasonable performance throughout this range. The maximum transconductance was 1.6 mS mm −1; the value of this parameter decreased with temperature. Similar data were obtained on both enhancement mode and depletion mode MOSFETs; the latter operated continuously as high as 923 K. Transconductances as high as 11.90 mS mm −1 were achieved.