AFM and HREM observation of the pulse laser interference crystallized a-Si:H/a-SiNx:H multilayers

The patterned nc-Si/a-SiNx:H superlattices were fabricated by using laser interference crystallization method and investigated with atomic force microscope (AFM), micro-Raman spectroscope, cross-section transmission electron microscope (TEM) and high resolution electron microscope (HREM). We found that after laser irradiation, self-assembled Si nanocrystallites (nc-Si) are formed within the initial a-Si:H sublayers, moreover, in the plane parallel to the surface of the films, these nc-Si orderly distribute in the certain regions with the same periodicity of 2.0 μm as phase shifting mask grating. Based on the structural analyses, the crystallization mechanism and the origin of the self-assembled phenomena are briefly discussed.