Study of spiral growth on 4H-silicon carbide on-axis substrates

We grew epitaxial layers on on-axis carbon-face 4H-silicon carbide substrates and investigated the growth conditions for the generation of spiral growth. We discovered that spiral growth occurs in regions where the local off-angle is less than 0.05° and when the spiral hillocks have a tilt angle of 0.06°. Moreover, we found that each spiral hillock coalesced without causing dislocation in the areas where the spiral growth occurred. Our results indicate that spiral growth is dominant when the spiral hillocks have a tilt angle greater than the off-angle of the substrate. Step-flow growth is overcome by spiral growth because the rate of spiral growth is greater than that of step-flow growth.