Defective Crystal Recovered from the Crystallization of Potassium-doped Amorphous Silicon Films

Abstract

The quality of a crystallized potassium-doped amorphous silicon film was investigated using transmission electron microscopy. It was discovered that the planar epitaxial growth of the amorphous layer was upset after a certain concentration of potassium was encountered by the interface. The crystal recovered subsequent to this point was twinned. The twins lie on {111} planes. The results from the transmission electron microscope analyses were correlated with the rate of solid-phase epitaxy as deduced using time resolved reflectivity and the potassium distribution measured using secondary ion mass spectroscopy. The roughening of the interface due to the growth of twins was determined as a function of depth from the extinction of reflectivity amplitude in the time resolved reflectivity trace.