CONDUCTIVE MICROCRYSTALLINE-SI FILMS PRODUCED BY LASER PROCESSING

Pulsed laser interference crystallization is applied to produce conduc tive boron-doped microcrystalline-silicon films. Three interfering bea ms of a frequency-doubled Nd:YAG-laser (gamma = 532 nm) form two-dimen sional interference patterns which generate periodic arrays of crystal lized nucleation centers (seeds) in amorphous Si films. The distance b etween neighboring seeds has been varied between 0.5 and 10 mu m to in vestigate the laser stimulated seeded lateral growth of the crystallit es. The crystallization is stimulated either by illumination of the la yer with a single laser pulse of high intensity or by a series of inte rfering laser pulses with increasing intensities. Atomic force microsc opy, scanning electron microscopy and X-ray diffraction are applied to investigate the structural properties of the crystallized layers. Gra ins about 10 times larger than for unseeded laser crystallization are obtained. This correlates with improved electronic properties such as conductivities to 2000 S/cm and mobilities greater than or equal to 10 cm(2)/Vs. (C) 1998 Elsevier Science B.V. All rights reserved.