Evaluation of Specific Contact Resistance of Al, Ti, and Ni Contacts to N Ion Implanted 3C-SiC(100)
The specific contact resistance of Al, Ti and Ni ohmic contacts to N+ implanted 3C-SiC(100) has been investigated by means of TLM method. The p-type epitaxial layer grown on n+ substrate is multiply implanted with N ions with energy ranging from 15 to 120 keV at a total dose of 1.4×1015 cm-2 at room temperature and is subsequently annealed by RF annealer at a temperature of 1400 oC for 10 min in Ar gas flow, resulting in the sheet resistance of 130 0/sq. The deposited Al layer on the annealed sample shows the extremely low specific contact resistance of about 1×10-7 0cm2. The ohmic contacts of Ti and Ni also show the specific contact resistance of 5×10-6 and 2×10-5 0cm2, respectively. The obtained specific contact resistance is proportional to the Schottky barrier height of metal cotact to n-type 3C-SiC. The annealing of Ni ohmic contact above 600 oC results in the considerable reduction of specific contact resistance due to the silicidation of Ni.