Effect of UV-O_2, NF_3/H_2 surface preparation on the crystalline defects in silicon homoepitaxy (Part I. A study on photochemical surface preparation in series)

摘要

In this work, the organic residue and oxide on silicon wafer were treated with UV-excited oxygen and trifluoronitrogen gases as a pre-treatment for silicon homoepitaxy. A typical positive photo resist, AZ 1512, was coated as a model organic residue. UV-O_2 cleaning (UVOC) and UV-NF_3/H_2 treatment removed the organic residue and native oxide layer, respectively, for silicon epitaxial growth. A study of removal rate showed that the processing temperature is a more critical process parameter than pressure. Besides, hydrogen dilution improves the surface roughness of UV-NF_3-treated surface as shown in the atomic force microscope images.