Excimer-laser-produced two-dimensional arrays of large Si grains

Experimental and theoretical results are reviewed for an excimer-laser-based Si large-grain growth method aiming at a 'system-on-panel' technology. Temperature in the Si thin layer should have a gentle slope along the one direction for growing large grains and should have a steep dip along the other direction for controlling their positions. In order to produce such a temperature distribution using an excimer- laser light pulse, phase-shifter patterns that generate the 2D distribution of the light intensity on the sample surface by Fresnel effects should be independently optimized for both directions. The sample should be of a stacked structure of the heat storage layer, the Si layer and the underlayer with low heat diffusing power. The Si layer thickness is a critical parameter for long grain growth, and should be very thin under the condition of the thick heat storage layer. The growth large grains seem to have excellent crystallinity although experimental data is not sufficient.