THE MECHANISM FOR CUBIC SIC FORMATION ON OFF-ORIENTED SUBSTRATES

The mechanism responsible for nucleation of 3C polytype on off-axis 4H and 6H substrates is investigated. 3C is shown to predominantly nucle ate at triangular stacking faults (TSFs), the structural defects induc ed by substrate imperfections. The TSFs suppress conventional step-flo w growth and promote the development of large on-axis (0 0 0 1) terrac es, The nucleation of 3C at those terraces occurs as a result of high supersaturation, in a similar manner as for on-axis SIC wafers. Both t he process parameters and the substrate quality are significant in pre venting the 3C incorporation into epitaxial layers.