Impact of PECVD-prepared interfacial Si and SiGe layers on epitaxial Si films grown by PECVD (200 degrees C) and APCVD (1130 degrees C)

Abstract

The homoepitaxy of Si is particularly interesting for the purpose of kerfless wafer production, for example in the photovoltaic domain. Substrate surface engineering is a key step prior to epitaxial growth, which will affect the quality of the epitaxial layer and its detachment for layer transfer. In this work, we propose two plasma-based surface engineering methods including the deposition of a bilayer homoepitaxial interface and a SiGe hetemepitaxial interface. Their impact on the crystalline quality of epitaxial Si layers grown both by plasma-enhanced chemical vapor deposition (PECVD) at 200 degrees C and by atmospheric pressure chemical vapor deposition (APCVD) at 1130 degrees C are explored. Stacking faults are observed in epitaxial Si layers with an ultra-thin epitaxial Si interface layer. For surface engineering method based on the addition of an interfacial heteroepitaxial SiGe layer, a higher interfacial hydrogen content and a better bulk epitaxial Si quality are observed in comparison with interfacial homoepitaxial Si layer.