Electrical and optical properties of polycrystalline silicon seed layers made on glass by solid-phase crystallisation

We used solid-phase crystallisation (SPC) of PECVD-deposited doped amorphous silicon (a-Si:H) on planar and textured glass to produce polycrystalline silicon (poly-Si) seed layers for subsequent epitaxial silicon growth. In this paper we present the effects of several parameters (SPC temperature profile, barrier layer on the glass, doping level of the a-Si) on the specific resistivity and the optical properties of the resulting poly-Si films. A low specific resistivity of 8 m/spl Omega/cm was achieved on barrier-coated textured glass for 100-nm a-Si:H films with a doping step, using a step-like SPC process (1 hr at 620/spl deg/C followed by 39.5 hrs at 580/spl deg/C). Modelling of the measured transmission spectra shows that the refractive index of the poly-Si films is very close to that of single-crystalline silicon.