THE INFLUENCE OF TEMPERATURE TREATMENT ON THE FORMATION OF NI-BASED SCHOTTKY DIODES AND OHMIC CONTACTS TO N-6H-SIC

Nickel-based Schottky contacts to n-6H-SiC, subjected to various heat treatments, have been studied by the capacitance-voltage technique, X- ray diffractometry and AES sputter depth profile methods. Substrate he ating during nickel deposition and additional annealing of Schottky co ntacts after deposition of metal film lead to differences in structure and composition between contact layers formed on Si- and C-faces. As a result a distinction in surface barrier heights in Schottky diodes f ormed on the C- and Si-faces has been observed. At annealing temperatu res higher than 400-600 degrees C formation of nickel silicides in the contact layer is starting. Low-resistance (<10(-4) Omega cm(2)) ohmic contacts to the 6H-SiC polar faces were fabricated after annealing Ni -n-6H-SiC Schottky diodes at 1000 degrees C. (C) 1997 Published by Els evier Science S.A.