I n s i t u spectroscopic ellipsometry investigation of the nucleation of microcrystalline silicon

I n situ spectroscopic ellipsometry is used to reveal the structural changes that occur in the initial stages of the growth of microcrystalline silicon (μc-Si) deposited by glow discharge decomposition of a (SiH4,H2) mixture on silica substrates. In a first step, the real time measurements can be described by the following nucleation model: stable nuclei are created, with an average distance between them estimated to be ∼100 Å, followed by the growth of three-dimensional crystalline islands. In a second step an interfacial component composed of amorphous silicon and voids is produced as a consequence of the incomplete coalescence of the crystalline islands.