Surface Structuring of Patterned 4H-SiC Surfaces Using a SiC/Si/SiC Sandwich Approach

TL;DR

This study demonstrates a novel SiC/Si/SiC sandwich method for surface structuring of 4H-SiC wafers, revealing insights into macrostep formation and Si spreading challenges in patterned surfaces.

Contribution

Introduces a new macrostep formation technique using Si melting in a sandwich configuration for patterned 4H-SiC surfaces.

Findings

Macrosteps formed on both dry-etched and unetched areas

Si spreading difficulties observed in trench-patterned samples

Preferential etching at Si-C bilayer step edges and lateral propagation along [1120]

Abstract

Mesa- and trench-patterned surfaces of 4H-SiC(0001) 4{\textdegree}off wafers were structured in macrosteps using Si melting in a SiC-Si-SiC sandwich configuration. Si spreading difficulties were observed in the case of trench-patterned samples while the attempts on mesa-patterned ones were more successful. In the latter case, parallel macrosteps were formed on both the dry-etched and unetched areas though these macrosteps rarely cross the patterns edges. The proposed mechanism involved preferential etching at Si-C bilayer step edges and fast lateral propagation along the [1120] direction.