Observation of swelling and sputtering of a silicon target under argon ion irradiation using a double marker technique

Abstract

The process of ion implantation results in sputtering at the surface and contraction and/or swelling in the bulk. This has been measured for 150 keV Ar + implanted into amorphous silicon films by sectioning the collision cascade with a double marker techniqie and observing the movement of the markers employing Rutherford Backscattering Spectrometery. The experimental data are compared with a computer simulation programme Trim-Cascade. The results for implant doses of 1 × 10 16, 2 × 10 16, and 5 × 10 16 ions cm −2 consistently indicate a common crossover depth between a sputtering and contraction dominated regime and a regime dominated by swelling. Excess contraction due to vacancies observed in the region of maximum nuclear energy deposition suggests radiation enhanced diffusion of interstitials towards greater depth.