화학공학소재연구정보센터
Thin Solid Films, Vol.374, No.2, 150-156, 2000
Atomistic simulation of silicon bombardment by energetic CF3+: product distributions and energies
We present an analysis of results obtained from molecular dynamics simulations of continuous bombardment of the Si surface with CF3+ ions at normal incidence in the energy (E-i) range of 25-200 eV. Our analysis is aimed at understanding how the distributions in products and their kinetic energies depend on E-i. As E-i increases, the product distribution is shifted toward a lower average molecular weight, and with atomic F and molecular CF becoming the most common product species at the higher incident energies. These findings agree well with recent experimental results. The kinetic energy distributions of the products are sensitive to E-i only in that the high-energy tail of the distribution becomes more prevalent with increasing E-i. Linear cascade theory predictions agree reasonably well with our kinetic energy distributions. Individual species product kinetic energy distributions are much more sensitive to E-i, and primarily reflect that most high-energy products are of low molecular weight. The product kinetic energy as a function of ejection angle is also sensitive to E-i, displaying an increasing maximum value with increasing E-i. These results could potentially help in the guidance and interpretation of molecular beam experiments which seek to detect products in simulated fluorocarbon plasma etching of silicon.