Laser temperature interlevel SiO2 layers by photoinduced processing

Polysiloxane layers were deposited from the gas phase by photoinduced polymerization reaction of tetraethylorthosilicate (TEOS) and O2/N2O. The deposition kinetics can be described by a gas phase polymerization and the subsequent condensation of the siloxane molecules. As UV light sources an ArF excimer laser (193 nm) and a 185/253 nm low pressure Hg-discharge lamp were used, the polysiloxane deposition rates are 2000 A/min or 1200 A/min respectively. In a second thermal or combined thermal/photoinduced process step the as deposited siloxane layers are transformed by hydrolysis and condensation reactions to pure SiO2. The composition of the as deposited and transformed polysiloxane layers were investigated by FTIR spectroscopy. Typical examples of the step coverage and planarizing properties of the SiO2 layers for the use as interlevel dielectrics are presented.