Role of gas phase reactions in subatmospheric chemical-vapor deposition ozone/TEOS processes for oxide deposition

Deposition rates, wet etch rates, and thickness uniformity experiments were performed using O3/TEOS thermal chemical-vapor deposition. Our results for oxide deposition show optimum process window around 200 Torr for producing films of good quality ~uniformity and material properties!. This is in excellent agreement with the modeling predictions over a broad range of pressure ~100–600 Torr! and temperature ~370–470 °C!. The model invokes both gas phase and surface reaction mechanisms. The former is needed to produce deposition precursors and leads to an observed increase-maximum-decrease dependence on the deposition pressure; this decrease is associated with a competing ~parasitic! role of gas phase reactions. Our experiments identify particle formation at higher pressures which is consistent with the expected dual role of gas phase reaction in generating ~1! required deposition precursors and ~2! particulates in the gas phase under some conditions. © 1996 American Vacuum Society.