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 O-3/TEOS thermal chemical-vapor deposition. Our results for oxide dep osition show optimum process window around 200 Ton for producing films of good quality (uniformity and material properties), This is in exce llent agreement with the modeling predictions over a broad range of pr essure (100-600 Torr) and temperature (370-470 degrees C), The model i nvokes both gas phase and surface reaction mechanisms. The former is n eeded to produce deposition precursors and leads to an observed increa se-maximum-decrease dependence on thr deposition pressure; this decrea se is associated with a competing (parasitic) role of gas phase reacti ons, Our experiments identify particle formation at higher pressures w hich is consistent with the expected dual role of gas phase reaction i n generating (1) required deposition precursors and (2) particulates i n the gas phase under some conditions. (C) 1996 American Vacuum Societ y.