Damage formed by ion implantation in silicon evaluated by displaced atom density and thermal wave signal

Abstract

Damage formed by BF+2 and As+ implantations in Si was evaluated quantitatively. The density of displaced atoms (Dda) was determined from 1.5 MeV He+ Rutherford backscattering spectrometery. Dda increased from 4.7×1016 to 1.6×1017 cm−2 with the dose increased from 6.0×1013 to 1.3×1014 cm−2. However, Dda saturates at around 4×1017 cm−2 for all doses above 5×1014 cm−2. The thermal wave signal intensity shows the same dose dependence as Dda. This result shows that thermal wave signal intensity has a close relation with the density of displaced atoms formed by ion implantation. Therefore, quantitative damage monitorings can be achieved by thermal wave intensity measurements. Also, the variation of thermal wave signal intensity with ion implant energy was studied.