Time-resolved investigation of large-area explosive crystallization of amorphous silicon layers

Abstract

Using time-resolved reflectivity measurements and a special irradiation technique to cause an abrupt stop of the crystallization the spreeding kinetics of the crystallization front during the explosive process is investigated. A system of three lasers operating with variable time delay is applied to provide the substrate temperature necessary, to control the ignition and to stop the explosion. The measurements yield an interval of 15 to 16 ms−1 for the velocity of the crystallization front and 1150 to 1250 K for the temperature during explosive crystallization. No significant dependence of the velocity on the quality of the virgin amorphous state of the layers produced by different methods, on the covered distance after ignition and even on lateral temperature gradients can be detected. The results gained from lpCVD-layers prove that nucleation and growth processes severely influence the liquid-phase explosion process.