Low-Temperature Atmospheric-Pressure Chemical Vapor Deposition Using 2, 4, 6, 8-Tetramethylcyclotetrasiloxane and Ozone

Tetramethylcyclotetrasiloxane (TMCTS) was studied as a possible silicon source for atmospheric-pressure chemical vapor deposition (CVD) using ozone chemistry. High-quality silicon dioxide films were produced at 400° C with a typical deposition rate of 100 nm/min. During the study, TMCTS was observed to have base material dependent characteristics which varied as a function of both deposition temperature and ozone concentration. The deposition rate vs deposition temperature relationship indicated that the film structure varies slightly as a function of the deposition temperature. Data collected for film shrinkage after annealing supported these structural changes. The typical as-deposited film stress was 2×109 dyn/cm2 (tensile). The step coverage varied from conformal to flow-shaped depending on the deposition temperature and ozone concentration. The results of this study show that TMCTS is a promising precursor for use in intermetal dielectric applications for ultra large-scale integration (ULSI) devices.