Theoretical study ofSiH3-defect stability and formation on the H-saturated Si(100)1×1 surface

We present first-principles calculations for the initial stages of etching of Si(100) by H atoms. We find that adsorbed ${\mathrm{SiH}}_3$ species [(${\mathrm{SiH}}_3$(a)] on the H-saturated Si(100)1×1 surface have a negative formation energy. Our results also indicate that the Si-Si backbond breaking which gives rise to the formation of these ${\mathrm{SiH}}_3$(a) defects is possibly promoted by a bonding state between hydrogen and silicon atoms in the second layer.