Properties of phosphorus-doped polycrystalline silicon films formed by catalytic chemical vapor deposition and successive rapid thermal annealing

摘要

Phosphorus (P) doped polycrystalline silicon (poly-Si) thin films are used as gate or capacitor electrodes for ultralarge-scale integrated circuits (ULSIs) and source/drain electrodes for thin-film transistors (TFTs) for active-matrix liquid-crystal displays (AMLCDs). However, the deposition temperature for conventional low-pressure chemical vapor deposition (LPCVD) is around 600°C or higher. Further reduction of thermal budget is desirable for forming shallow junction in ULSIs and for avoiding substrate damages in AMLCDs. It is known that amorphous silicon (a-Si) films prepared by catalytic chemical vapor deposition (Cat-CVD) contain a few amounts of hydrogen (H) [1]. This is an advantage to transform a-Si films to poly-Si films by annealing since it is expected to eliminate H bubbling causing rough surface. Therefore, poly-Si films with both low resistivity and perfect flatness are expected using Cat-CVD process. In the present work, properties of P-doped poly-Si films prepared by Cat-CVD and successive rapid thermal annealing (RTA) were investigated.