Sk. Kwon et al., Silicon epitaxial film growth on silicon substrate exposed to UV-excited NF3/H-2 gas for native oxide removal, J CRYST GR, 199, 1999, pp. 1039-1044
In situ UV-excited NF3/H-2 gas phase cleaning for native oxide removal and
Si epitaxial him growth experiments were carried out in a load-locked react
or equipped with a UV lamp and PEN heater. The effect of composition of NF3
/H-2 and UV exposure on the etching characteristics of native oxide and the
rmal oxide has been studied. Main etching species were identified as F, NFx
and HF. Hydrogen added to NF3 gas alleviates silicon surface pitting to re
sult in the very smooth surface. RMS surface roughness was as low as 0.5 An
gstrom at the ratio of H-2/NF3 of 3. Analysis of silicon eptaxial film show
ed the effectiveness of NF3/H-2 gas phase cleaning as the pretreatment proc
ess prior to silicon eptaxial him growth. (C) 1999 Published by Elsevier Sc
ience B.V. All rights reserved.