Cleaning of Silicon Surfaces by $\bf NF_{3}$-Added Hydrogen and Water-Vapor Plasma Downstream Treatment

Native oxide was removed from silicon surfaces by NF3-added hydrogen and water-vapor plasma downstream treatment. It took 45 s to remove native oxide from a 6-inch silicon wafer. Fourier transform infrared attenuated total reflection (FT-IR ATR) measurement revealed that the surface roughness after the downstream treatment was the same as that after wet cleaning with 2% HF solution. A silicon epitaxial layer was grown on the surface cleaned by the downstream treatment. Although process temperature was as low as 100 degrees C, the present downstream treatment induced the same effect as in situ hydrogen annealing.