MONTE-CARLO SIMULATIONS OF ION-ASSISTED SELECTIVE DEPOSITION

One way of obtaining selective deposition is by high bias sputtering. This has been verified experimentally. If for example two different substrate materials are subjected to the same argon ion bombardment during film deposition, a net film deposition may occur at one of the substrates while the other remains uncovered. This phenomenon has also been treated theoretically, assuming different sputtering yields for the deposited atoms depending on the underlying substrate material. It is, however, not easy to treat this effect analytically. In this article the film formation and the dependences of the sputtering yield of deposited atoms on different substrate materials are studied by Monte Carlo simulations of the induced collision cascades. The simulations are based on the well established TRIM code. A new version called T-DYN was used to include dynamic phenomena during film growth or sputter etching of the substrates. The results from the simulations predict the experimentally found results.