부산대학교 도서관

Hydrogenation of polycrystalline silicon (poly-Si) passivating contacts is crucial for maximizing their passivation performance. This work presents the application of Al 2 O 3 prepared by atomic layer deposition as a hydrogenating capping layer. Several important questions related to this application of Al 2 O 3 are addressed by comparing results from Al 2 O 3 single layers, SiN x single layers, and Al 2 O 3 /SiN x double layers to different poly-Si types. We investigate the effect of the Al 2 O 3 thickness, the poly-Si thickness, the poly-Si doping type, and the postdeposition annealing treatment on the passivation quality of poly-Si passivating contacts. Especially, the Al 2 O 3 /SiN x stack greatly enhances the passivation quality of both n + and p + doped as well as intrinsic poly-Si layers. The Al 2 O 3 layer thickness is crucial for the single-layer approach, whereas the Al 2 O 3 /SiN x stack is less sensitive to the thickness of the Al 2 O 3 layer. A thicker Al 2 O 3 layer is needed for effectively hydrogenating p + compared to n + poly-Si passivating contact. The capping layers can hydrogenate poly-Si layers with thicknesses up to at least 600 nm. The hydrogenation-enhanced passivation for n + poly-Si is found to be more thermally stable in comparison to p + poly-Si. These results provide guidelines on the use of Al 2 O 3 capping layers for poly-Si contacts to significantly improve their passivation performance.