Low thermal budget surface cleaning after dry etching for selective silicon epitaxial growth

Abstract

We studied the influence of plasma etching damage on epitaxial Si growth using ultrahigh vacuum chemical vapor deposition. The damaged layer induced on substrate surface had an amorphous structure that had some carbon, oxygen, and fluorine in its composition. The damaged layer was removed by in situ preheating above 850°C, before the growth, or by chemical dry etching (CDE). We found that CDE has the effect of decreasing the preheating temperature by 200°C as compared to the case without CDE. Furthermore, the dependence of the surface roughness of grown films on post-etching treatments is also discussed.