LPCVD in-situ doped silicon for thermoelectric applications

In semiconductor industry doping of polysilicon materials is often achieved with ion-implantation, provoking a relatively high thermal budget. In this study we have analyzed an alternative approach via LPCVD in-situ phosphorus doping with subsequent RTA on 150 mm/300 mm wafers in order to obtain Si-based materials for thermoelectric applications. With this process integration a lowering of the thermal budget, a release of film stress and an enhancement of throughput are achieved. Additionally, the dopants are distributed uniformly and there are more process tuning possibilities with this process integration. The investigation includes ToF-SIMS for depth profiling of the dopant and XRD/ SEM analysis for microstructure analysis. The a-Si:P with RTA and poly-Si:P with RTA thin films were patterned in order to investigate the thermoelectric properties. The results suggest these LPCVD in-situ P-doped Si-based materials as suitable candidates for practical applications in the semiconductor industry.