Epitaxial growth
In SiC epitaxy, what is the phenomenon called in which many atomic surface steps gather into large steps, roughening the surface?
- ADishing
- BStep bunching
- CNecking
Show answer and explanation
Answer: B. Step bunching
On offcut substrates, the crystal grows along steps, but under some conditions several steps gather into tall steps. This is called step bunching, and because the surface roughness degrades MOS interface properties, it is suppressed through growth conditions and surface treatment.
- A. Dishing is the recessing of a line's center during CMP.
- B. Correct. Steps gather into large ones.
- C. Necking narrows the crystal during single-crystal pulling.