TEM analysis of Si thin films prepared by diode laser induced solid phase epitaxy at high temperatures

The solid phase crystallization of amorphous silicon thin films deposited on 〈111〉-oriented wafers at high temperatures was investigated. The films were heated up by diode laser irradiation for some milliseconds to seconds. Time resolved reflectivity measurements together with numerical temperature calculations showed that temperatures above 1000 °C were reached before significant crystallization took place. By comparing two different laser intensities it is shown that random nucleation and growth dominate solid phase epitaxy if high temperatures are reached faster. The interface between epitaxially grown and randomly crystallized material is very rough which can be attributed to contaminations found at the substrate-film interface.