A dry cleaning process for removing metal contaminants from a surface of an oxide film includes the steps of: forming a reaction area on the oxide film such that a silicon surface is formed in correspondence to the reaction area, supplying a dry cleaning gas selected from a group essentially consisting of chlorine, bromine, hydrogen chloride, hydrogen bromide and a mixture thereof, to the oxide film including the reaction area, to produce silicon halide molecules as a result of a reaction between the dry cleaning gas and the silicon surface, supplying the silicon halide molecules to a surface of the oxide film, and removing metal elements existing on the surface of the oxide film as a result of a reaction between the metal element and the dry cleaning gas under a presence of the silicon halide molecules.