High accuracy interatomic potential model for binary collision approximation and its application into sputtering yield estimation for amorphous carbon

Abstract

Although binary collision approximation (BCA) and molecular dynamics (MD) are well used for plasma-material interaction simulation, the atomic collision in the energy above 10 eV is often out of scope in general potential model for MD. For BCA, the Ziegler–Biersack–Littmark (ZBL) potential has been often employed for high energy collision. In the present work, as one of modernizations of BCA, more accurate potential model for high energy collision, which is named ReGenerated ZBL (ReGZ) potential, was proposed. The function from of the ReGZ potential was analytically derived from the spherical electron density of an independent atom. To evaluate the potential, sputtering yield and reflection coefficient were compared between the BCA simulations using the ReGZ potential and the ZBL potential. In addition, by also improving the surface binding energy by density functional theory, the sputtering yield using the ReGZ potential becomes consistent with existing results.