CHEMICAL TREATMENT OF GLASS SUBSTRATES

The effects of cleaning on the near-surface composition of Corning Cod e 1737 glass was studied. Cleaned glass substrates were found to devel op a thin silica-rich surface layer approximately 6 nm thick formed by chemical leaching. The presence of this layer was verified by X-ray p hotoelectron spectroscopy, scanning transmission electron microscopy a nd X-ray scattering. Atomic force microscopy measurements of the glass before and after cleaning showed no increase in the surface roughness . Top-gated polycrystalline silicon thin film transistors fabricated o n cleaned substrates had leakage currents, similar to those on substra tes with deposited SiO2 layers. (C) 1997 Elsevier Science B.V.