Ion-Assisted Regrowth of Deposited Si Layers Mechanisms and Morphology

Abstract

Ion-assisted regrowth of chemical vapor deposited amorphous Si layers was investigated for different cleaning procedures. The process was directly monitored by transient reflectivity measurements. The c-a interface stops at the deposited layer/substrate interface for doses depending on the effectiveness of the cleaning procedure in removing the native oxide. Small concentrations of twins are found in the regrown layer. Their amount is also correlated to the cleaning procedure. In oxygen implanted bare Si samples the ion-induced growth rate is reduced to 0.3 of the normal value at a peak O concentration of 1 X 1021/cm3. The results on the ion-induced regrowth of deposited layers are explained in terms of oxygen profile broadening during irradiation and retardation of the growth for the presence of dissolved O.

Amorphization/recrystallization of buried amorphous silicon layer induced by oxygen ion implantation

“…[8][9][10] Hence, dopant atoms, like B, P and As, enhances the IBIEC rate 7 whereas O atoms reduces it. 7,11,12 For ion implantation at temperatures T i Ͻ200°C, the damage accumulation prevails over the IBIEC process, leading to the expansion of the existing a-Si region through layer by layer amorphization.…”