Application of a chemical trap to an aluminium/chlorine etching process

Abstract Aluminium etching is an important production step in integrated circuit fabrication. Chlorinated gases are widely used because of their high efficiency. These gases and the byproducts formed in the plasma reactor are highly toxic and/or corrosive, thus being hazardous to operators and equipment. A chemical trap, designed to remove chlorinated compounds from the exhaust stream before they enter the pumping manifold, was tested on a production type aluminium etcher. The process utilized Cl 2 and CCl 4 as active gases. Efficienct of the cleaning action under various conditions, trapping capacity, handling and cleaning of the trap are reported. The application of the device to other gas mixtures is discussed.