SURFACE REACTIVITY MEASUREMENTS FOR OH RADICALS DURING DEPOSITION OF SIO2 FROM TETRAETHOXYSILANE O-2 PLASMAS/

The surface reactivity of OH radicals has been measured during plasma deposition of SiO2 from tetraethoxysilane (TEOS)-based plasmas by the Imaging of Radicals Interacting with Surfaces (IRIS) method. This tech nique combines molecular beam and plasma technologies with spatially-r esolved laser-induced fluorescence to provide two dimensional images o f radical species during surface modification. OH radicals were not de tected in a 100% TEOS plasma, but were observed in 20% TEOS/80% O-2 pl asmas. The reactivity of OH is measured as 0.40 +/- 0.10 while deposit ing SiO2 on a 300 K Si substrate. This intermediate reactivity indicat es that OH may play a role in formation of SiO2 films.