Advantages of single and mixed species chaining for high productivity in high and mid-energy implantation

Chaining implant steps improve device performance and yield, enhance throughput, and reduce manufacturing time, cost and risk. A typical implant chain consists of two to four steps of varying energy, dose and Implant angle, and may also include multiple species. High-energy (HE) well implants, including threshold voltage (V
_t
) adjusts, are Ideal candidates for chaining due to their location in the process flow, similarity in mask sets, and beam current requirements. In the present study, we prove feasibility of same species"" and ""mixed species"" chains with high throughput in multi-wafer ion implanters. Throughput models have been generated to examine how mixed species chains improve machine productivity. Optimization of chains is achieved through characterization of the hardware and optimization of the software to allow for flexibility In setting up and running chains. Measurements of energetic and surface contamination in the mixed species chains demonstrate the implanter's capability of running chains without any contamination problems. Results on tune/transition times between chain recipes are presented, and subsequent throughput enhancements are discussed.