EVALUATION OF OHMIC CONTACTS TO P-TYPE 6H-SIC CREATED BY C AND AL COIMPLANTATION

A comparative study of specific contact resistance and sheet resistivi ty of p-type 6H-SiC created by Al implantation only and by C and Al co implantation into n(-)-6H-SiC epilayer grown on n(+)-6H-SiC has been p erformed to address the challenging issue of ohmic contacts to the ano de of SIC thyristors and other thyristor-based advanced devices. Direc t experimental evidence has been obtained which shows the obvious adva ntage of C and Al coimplantation in terms of contact resistance and sh eet resistivity, Under our experimental conditions, it is found that t he specific contact resistance can be reduced by three orders of magni tude and the sheet resistivity can be improved by a factor of 6 when C and Al are coimplanted into 6H-SiC.