Materials Science Forum, Vol.457-460, 241-244, 2004
Vapour-Liquid-Solid induced localised growth of heavily Al doped 4H-SiC on patterned substrate
We are developing a new approach for SiC selective growth by vapour-liquid-solid (VLS) mechanism in which propane feeds an Al-Si melt. In a first step, a stacking consisting in 500 nm thick Si layer followed by 1 pm thick Al layer was deposited on top of a 4H-SiC, 8degrees off substrate. This stacking was patterned to obtain various geometrical motives. For the VLS growth, the sample was heated up to 1000degreesC so that the Al and Si layers reacted giving local melts which were fed by propane to grow SiC selectively. This process was successful to obtain selective SiC epitaxy with various dimensions and shapes. It was found that the width of the pattern lines have to be as small as possible (< 20 mum) in order to avoid circular droplet formation. Under this value, regular SiC lines were formed. Raman characterization shows that the areas where growth occurred are highly p-type doped.