Low Temperature Processing Of A Large Grain Poly Crystalline silicon Thin Film On Soda-lime Glass

摘要

We have demonstrated that a polycrystalline silicon thin film can be fabricated in situ on soda-lime glass at 450 °C by an Al-induced crystallization method using electron beam evaporation. The catalytic Al is found to diffuse to the top of the crystallized Si layer and can be easily etched away by a mixture of acids. This low temperature Si crystallization process is well explained by thermodynamic consideration. Subsequent annealing at the same temperature (450 °C) for 6 h improves the crystallinity of the film and enlarges the average grain size to over 5 um. There are no observable impurity phases. The poly-Si thin films are (1 1 1) oriented and all the grains are well aligned. A defect-free and excellent crystalline structure has been revealed by transmission electron microscopy. The measured resistivity, carrier concentration and charge mobility of these as-prepared poly-Si thin films indicate that our present low temperature processing technique has great advantage and prospect for the photonics industry.