Native Oxide Removal on Si Surfaces by NF3-Added Hydrogen and Water Vapor Plasma Downstream Treatment

NF3 was injected into the downstream of hydrogen and water vapor plasma to produce etching species without generating fluorine atoms, and native oxides on Si(111) surfaces formed in H2SO4/H2O2 solution were removed. The absence of fluorine atoms in the plasma and the downstream was confirmed by monitoring with a monochromator and an ESR spectrometer, respectively. Thus, etching of the quartz surface of a chamber which led to particle generation was not observed. The Si surfaces after the downstream treatment were investigated and compared with that after HF wet cleaning using attenuated total reflection Fourier transform infrared (FT-IR ATR) spectroscopy and X-ray photoelectron spectroscopy (XPS).