Crystallized Si films by low-temperature rapid thermal annealing of amorphous silicon

Abstract

Low-temperature rapid thermal annealing has been used to crystallize both undoped and doped amorphous silicon (a-Si) films deposited at low temperatures. The polycrystalline films produced are completely crystallized with time temperature budgets such as 4 min at 700 °C. Unlike deposited polycrystalline Si films, the grain size in these crystallized films is not limited by film thickness. In the case of undoped a-Si films crystallized by this approach, the resulting conductivity is comparable to that achieved in undoped polycrystalline Si films produced by much higher processing temperatures. In the case of doped a-Si films, the resulting crystallized film yields a conductivity of 160 S/cm, a value which is comparable to the highest reported for doped polycrystalline and microcrystalline silicon. These doped films are found to have mobility values of ∼13 cm2/V s.