NEW FEATURES OF THE LAYER-BY-LAYER DEPOSITION OF MICROCRYSTALLINE SILICON FILMS REVEALED BY SPECTROSCOPIC ELLIPSOMETRY AND HIGH-RESOLUTION TRANSMISSION ELECTRON-MICROSCOPY

Spectroscopic ellipsometry and high resolution transmission electron m icroscopy have been used to characterize microcrystalline silicon film s, We obtain an excellent agreement between the multilayer model used in the analysis of the optical data and the microscopy measurements. M oreover, thanks to the high resolution achieved in the microscopy meas urements and to the improved optical models, two new features of the l ayer-by-layer deposition of microcrystalline silicon have been detecte d: (i) the microcrystalline films present large crystals extending fro m the a-Si:H substrate to the film surface, despite the sequential pro cess in the layer-by-layer deposition; and (ii) a porous layer exists between the amorphous silicon substrate and the microcrystalline silic on film. (C) 1996 American Institute of Physics.