Sputtered Amorphous Silicon Thin Films for Diode Laser Crystallization
in: Materials Letters (2012)
Multicrystalline silicon thin films with large grains (100 µm) on glass are useful for thin film solar cells and for thin film transistors. These films can be prepared by diode laser irradiation of amorphous silicon films, which previously had been deposited by PECVD or electron beam evaporation. Here, the applicability of sputtered amorphous silicon thin films on glass for diode laser crystallization is investigated. For this process the in- film sputter gas content and the optical properties, particularly the absorption for the diode laser wavelength of 808 nm, are crucial. In this paper the sputtering parameters gas pressure and power are optimized for increasing the absorption and for decreasing of sputter gas incorporation. It is demonstrated that using optimum deposition parameters diode laser crystallization leads to large grained multicrystalline silicon thin films. The crystallized layers show, different to previous results, a preferred (100)-orienation.
DOI: Array