Long-throw low-pressure sputtering technology for very large-scale integrated devices

For the next generation of semiconductor devices, new metal deposition technologies (such as Cu and Ti chemical vapor deposition) are being developed. As very large-scale integrated fabrication becomes more highly integrated, the size of contact/via holes must shrink, producing higher aspect ratios. These geometries create major difficulties in obtaining acceptable step coverage of the barrier/glue layer within the contact/via holes. A new technology has been developed, called long-throw sputter (LTS), for achieving acceptable step coverage particularly for geometries below 0.5 μm without employing collimators in the system. LTS (patent pending) provides more than 40% bottom coverage of barrier metal films in 0.35 μm contact holes with 3.0 aspect ratio while maintaining a high deposition rate and acceptable film uniformity. Additionally, LTS may facilitate Al alloy flow and/or reflow application.