D. Toet et al., LARGE-AREA POLYCRYSTALLINE SILICON THIN-FILMS GROWN BY LASER-INDUCED NUCLEATION AND SOLID-PHASE CRYSTALLIZATION, Thin solid films, 296(1-2), 1997, pp. 49-52
We present investigations on a two-step technique for the growth of po
lycrystalline silicon thin films on glass substrates. In the first ste
p, a lattice of artificial seeds is created by laser crystallization o
f amorphous silicon. In the second step, crystallites are grown around
the seed by thermal annealing below 600 degrees C. For seed separatio
ns of 7 mu m, adjacent crystallites can coalesce before spontaneous nu
cleation becomes apparent. Transmission electron microscopy reveals th
at the crystallites are star shaped, consisting of domains separated b
y twin boundaries. Microscopic reflection difference spectroscopy meas
urements reveal the existence of a radial stress pattern around the se
eds. We conjecture that this stress drives the lateral growth around t
he seeds during thermal annealing.