Polycrystalline Silicon on glass obtained by nickel induced crystallization of amorphous silicon

J.SCHMIDT, N.BUDINI, G.RISSO, R.ARCE, R.H.BUITRAGO

PHYSICA STATUS SOLIDI A-APPLIED RESEARCH

WISLEY

Año: 2009

0031-8965

In this work, we use the nickel-induced crystallization process to crystallize a-Si:H thin films at temperatures compatible with the utilization of glass substrates. Hydrogenated amorphous silicon films are deposited on planar float glass (Schott AF37) by plasma-enhanced chemical vapour deposition. The films, between 400 and 1400 nm thick, are grown intrinsic, slightly p-type (p-) and combined highly/slightly p-type (p+/p-). On these films we sputter nickel with concentrations between 2.5×1014 and 3×1015 at./cm2, and then we anneal the samples in a standard nitrogen-purged tube furnace. The process evolves through the formation of the nickel silicide NiSi2, which has a lattice constant very similar to that of c-Si and acts as a nucleation centre. As a result of this thermal treatment we obtain thin polycrystalline films with a grain size over 100 mm. The high crystallinity of the samples is confirmed through optical and electron microscopy observations, X-ray diffraction and Raman spectroscopy.