A method for forming upon a substrate employed within a microelectronics fabrication a silicon nitride dielectric layer with attenuated defects and inhomogeneities. There is provided one or more substrates. There is then provided a reactor tube which is part of an apparatus suitable for providing various gases at elevated temperatures. There is then purged the reactor tube with an inert gas in a low temperature cycle purge (LTCP) step at a temperature below deposition temperature. There is then placed the substrate(s) within a reactor tube. There is then deposited a silicon nitride dielectric layer upon the substrate(s), employing silane and ammonia gases employing a low pressure chemical vapor deposition (LPCVD) method. There is then purged the reaction tube at a temperature below the deposition temperature, followed by removal of the substrate carrier with attenuated formation of particulates and inhomogeneities within and about the silicon nitride layer and reaction tube.