AVS 50th International Symposium
    Thin Films Thursday Sessions
       Session TF-ThA

Paper TF-ThA2
Quasi-Real Time in-situ FT-IR Spectroscopy of Doped and Undoped SiO@sub 2@ Deposition from TEOS / Ozone Chemistry

Thursday, November 6, 2003, 2:20 pm, Room 329

Session: In-Situ / Ex-Situ & Real-Time Monitoring
Presenter: L.D. Flores, University of California, San Diego
Authors: J.E. Crowell, University of California, San Diego
L.D. Flores, University of California, San Diego
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Application of quasi- real time in-situ infrared spectroscopy to the chemical boundary layer (CBL) region formed during atmospheric pressure chemical vapor deposition is investigated for silicate glass deposition from TEOS / Ozone, and upon addition of phosphorus and boron dopants. The CBL-FT-IR methodology provides direct chemical measurement of the deposition intermediates formed upon dopant addition allowing for measurement of both film forming precursors and film formation processes. Similarly, CBL difference spectroscopy (CBL-DS) provides a sensitive measurement of the time needed for attainment of steady state reactor conditions after introduction or switching of reagents. Partial least squares Beer's law quantitative methods applied to the isolated form of ethoxysilanol (3737 cm@sup -1@) show that its concentration is reduced by a factor of 2 during growth of PSG under steady state conditions. We have developed a PLS methodology to quantitate reactive chemical mixtures of TEOS and ozone and found the chemical kinetics to be independent of added phosphite (i.e. [k@sub TEOS@/k@sub OZONE@]@sub PSG@ ~ [k@sub TEOS@/k@sub OZONE@]@sub USG@). Considering the ca. 2.8-fold enhancement in deposition rate observed upon phosphorus addition along with the measured reduction in gas phase isolated silanol groups illustrates that gas phase ethoxysilanol species are the main film deposition intermediates in equilibrium with SiO@sub 2@ film growth. This result shows that real time CBL-DS is a powerful methodology to determine the chemical mechanisms of film growth as well as the associated chemical kinetics of gas phase processes responsible for their growth. Spectroscopic differences and comparisons for PSG, BSG, and BPSG film growth and the associated intermediates will additionally be made.