Scalable control of graphene growth on 4H-SiC C-face using decomposing silicon nitride masks

TL;DR

This paper presents a method to control the number of graphene layers on silicon carbide by using silicon nitride masks that decompose during growth, enabling patterned and layer-specific graphene fabrication.

Contribution

It introduces a novel approach using decomposing silicon nitride masks to selectively increase or decrease graphene layers during epitaxial growth on SiC.

Findings

Si-rich SiN masks increase graphene layers by 1-4.

N-rich SiN masks decrease graphene layers by three.

Patterned graphene with good quality achieved through tailored growth parameters.

Abstract

Patterning of graphene is key for device fabrication. We report a way to increase or reduce the number of layers in epitaxial graphene grown on the C-face (000-1) of silicon carbide by the deposition of a 120 nm to 150nm-thick silicon nitride (SiN) mask prior to graphitization. In this process we find that areas covered by a Si-rich SiN mask have one to four more layers than non-masked areas. Conversely N-rich SiN decreases the thickness by three layers. In both cases the mask decomposes before graphitization is completed. Graphene grown in masked areas show good quality as observed by Raman spectroscopy, atomic force microscopy (AFM) and transport data. By tailoring the growth parameters selective graphene growth and sub-micron patterns have been obtained.