Influence of Deposit Thickness on the Microstructure and Surface Roughness of Silicon Films Deposited from Silane

摘要

Low pressure chemical vapor deposited silicon films characteristics required for the new emerging applications as for more classical uses, such as the fabrication of integrated circuits, become each day more severe. As a consequence, an accurate understanding of the mechanisms governing a microstructure formation is now mandatory to conveniently satisfy these new industrial requirements. In this objective, mixed-phase silicon films with thicknesses ranging from 5 to 385 nm have been deposited from silane onto SiO_2 substrates at the same deposition conditions of temperature (580 deg C) and total pressure (200 mTorr) but for varying times. The microstructure and surface roughness of each deposit have been investigated using a large range of techniques. After presenting the numerous results obtained, a new deposition mechanism is proposed.