Physics and modeling of dopant diffusion for advanced device applications

Physically based diffusion models have been developed to simulate dopant diffusion for advanced semiconductor device technology. Based on extensive experimental results and fundamental defect related kinetics, the diffusion models has been developed to include various diffusion species and defect reactions in order to simulate the complex dopant redistribution due to transient enhanced diffusion (TED).; For next generation channel doping technology, the experiment and modeling of indium diffusion during high temperature rapid thermal annealing (RTA) was carried out. The diffusion of implanted indium is a combined effect of TED and thermal equilibrium diffusion. The implanted indium cannot be fully activated after RTA due to carrier freeze-out. A diffusion model was developed to describe the indium redistribution during RTA.; The TED induced by ion implantation was extensively investigated for the phosphorus diffusion during low temperature furnace annealing. The TED of implanted phosphorus shows an initial decay at the early stage of annealing, and increases with increasing implant energy and dose. Dose loss of phosphorus was found during the TED period due to interface segregation. TED was shown to dominate the dose loss process. The Hybrid diffusion model including defect clustering and interface segregation effects was developed. The model accurately simulates the TED and dose loss of implanted phosphorus during low temperature annealing.; The co-diffusion study for arsenic and boron was performed to understand the boron redistribution in the channel region due to the TED caused by the arsenic source/drain implant. The boron segregation in the arsenic profile is induced by the combined effects of junction electric field and TED during annealing. The segregation is driven by the TED caused by either ion implantation or arsenic deactivation. To simulate the co-diffusion phenomenon, dislocation and arsenic clustering kinetics and their interactions with point defects are included. Results show that arsenic deactivation causes additional boron segregation which affects channel doping profile greatly and degrades the device performance.