A system and method for discarding expired network data packets is provided. In addition, a method is provided which includes growing an oxide film upon a semiconductor topography in the presence of an ozonated substance and depositing a silicon nitride film upon the oxide film. At least the flying lead portion of the conductive lead is formed from conductive material resistant to the first etching process. The marks in each of the first and second groups are arranged in the first direction over a predetermined range on the object. The fire resistant composition includes a halogen-free propylene resin containing propylene as its main monomer component, a halogen-free styrene-based thermoplastic elastomeric resin modified with an unsaturated carboxylic acid or a derivative of such an acid, and a fire resistant metal hydroxide. In cooling after the heating process, based on the temperature measurement result, the controller controls the temperature in cooling the semiconductor wafer, for each of the plurality of regions.