A multiple target sputter system with enhanced wafer uniformity, lifetime uniformity, and wafer scaleability

A physical vapor deposition (PVD) system configuration is proposed which consists of three concentric sputter targets which are independently controlled in real time. A "virtual reactor" which models this PVD configuration at the macroscopic equipment scale and microscopic VLSI feature scale has been developed. The simulator predicts that such a system is capable of enhanced film thickness uniformity and contact coverage uniformity compared to conventional single target systems. Because active feedback compensates for equipment variations between periodic maintenance, such as collimator clogging, the proposed system provides enhanced run-to-run uniformity. Additionally, because the system utilizes programmable control, a system with the proposed configuration adapts to changes in design parameters such as wafer size scaling.<>