Patterning with the use of ion-assisted selective deposition

Abstract

High bias sputtering in inert argon may be used to selectively deposit thin films on patterned substrates. Simultaneous sputter etching and film deposition will, at the initial stage of film formation, cause a newly discovered interface phenomena. The sputtering yield of a monoatomic thin film will strongly depend on the underlying bulk substrate. During ion bombardment of a growing ultra-thin film on top of a patterned substrate the film may be preferentially sputter eroded on areas where the sputtering yield of the thin film has the largest value. If a critical balance between deposition rate and sputter erosion rate is selected, actual selective large area deposition may be obtained. No degradation of the pattern was observed after selective deposition. This rules out the possibility of any contribution from local variations in the glow discharge to this selective deposition effect. We will also show that it is possible to predict the selectivity between different substrate materials by simulation of the sputtering yield values of the thin film by Monte Carlo calculations of the collision cascade process.