Understanding the growth of p-doped 4H-SiC layers using vapour–liquid–solid transport

• Localized growth of SiC layers was realized using VLS transport on SiC substrate.
• Heavily p‐doped SiC layers were obtained by keeping the shape of the patterns.
• Regular step bunched morphology was obtained when using 40 at.% Si in Si/Al alloy.
• Si content higher than 30 at.% is needed to avoid the Al4C3 stability conditions.

The present study reports the fabrication of localized p-doped silicon carbide zones on 4H-SiC substrate. Selective epitaxial growth of p-doped SiC was performed using the vapour–liquid–solid transport in Al–Si liquid phase. Focus was made on the understanding of the mechanism involved during such growth. It was shown that despite the need of starting the growth during the heating ramp, the deposition proceeds in a 2D manner at low temperature. Rather high growth rates were obtained (56.7–380 nm/min) which are related to the thinness of the liquid phase (< 3 μm). Argon carrier gas leads to an increase of growth rate compared to H2 due to the reducing effect of this latter gas. The results revealed that the surface morphology was more affected by the initial Si content of the liquid than by the growth rate. It is proposed that the Si content of the liquid is a very influent parameter because of its importance in the competition between SiC or Al4C3 stabilization.