Carbon implantation performance improvement by using carbon monoxide (CO) gas on applied materials VIISta HCS implanter

摘要

Carbon implant has become one of the major co-implant steps in the fabrication of advanced semiconductor devices due to its proven effectiveness in controlling and reducing Transient Enhanced Diffusion (TED) in ultra-shallow junction formation. Carbon dioxide (CO) is still widely used as the feed gas for carbon implantation. However, it is well known that the high concentration of oxygen from CO causes many problems, including oxidation of the implant arc chamber components, which leads to rapid performance degradation of the source. Phosphine (PH) is often used as a dilution gas to minimize the oxidation effect from CO. However, its use usually results in a reduction of the C beam current, thereby negatively impacting the tool's productivity. In this paper, carbon monoxide (CO) is presented as an alternative carbon doping gas replacing CO or CO with PH dilution (referred to as CO/PH throughout this paper). CO is shown to exhibit distinct performance improvements compared to CO/PH on the Applied Materials VIISta HCS high current implanter. Significant improvement in C beam current and source life with CO gas is noted.