Grain matrix made with excimer-laser crystallization of thin silicon films

By applying a method of location control in which heat sinks underlying an amorphous silicon film control the temperature of the film during and after excimer-laser irradiation, a matrix of adjacent grains with a diameter of 2.2 mu m was grown. The influence of several parameters on the yield of location controlled grains has been investigated. It is shown that location control is very sensitive to the laser-irradiation energy density and therefore beam non-uniformities have a devastating effect on the total yield of location-controlled grains. The yield was at best 8% (for an energy density of 643 mJ/cm(2)), but will be increased when beam non-uniformities are absent. Further increase in yield can be achieved by changing shape and material of the heat sink.