Structural and electronic properties of ultrathin polycrystalline Si layers on glass prepared by aluminum-induced layer exchange

We prepared ultrathin polycrystalline silicon layers (5-100 nm) by the aluminum-induced layer exchange process. An Al/oxide/amorphous Si layer stack was annealed at temperatures below 577 °C, leading to a layer exchange and the crystallization of the silicon. The process dynamics, structural and electronic properties have been studied. In addition to the well known dependence on the annealing temperature, we found an increase of the nucleation density with layer thickness. Raman spectroscopy shows a good crystalline quality down to a layer thickness of 10 nm. Hole concentrations of the p -type layers are between 5× 1018 and 9× 1019 cm-3, depending on layer thickness and annealing temperature.