Dry exhaust gas conditioning

A gas treatment method for use in connection with processes of etching semiconductor devices or of plasma enhanced chemical vapor deposition onto semiconductor materials, the gas treatment method comprising exposing exhaust gases of the processes to first and second active chemical components while heating the first and second active chemical components, wherein the exhaust gases contain at least one component selected from a group consisting of chlorine, silicon tetrachloride, copper chloride, aluminum chloride, silicon tetrafluoride, trifluoromethane, carbonyl fluoride, carbonyl chloride, boron trichloride, boron tribromide, hydrogen chloride, carbon tetrachloride, chloro-fluoro carbon gases, silane, dichlorosilane, tetraethylorthosilicate, diborane, trimethyl borate, phosphine, trimethyl phosphite, and arsine, wherein the first active chemical component is silicon or a silicon-rich alloy or a silicon rich substance and wherein the second active chemical component is calcium oxide, a calcium oxide containing material, or a soda lime containing medium.