Abatement of emissions from advanced chemical vapor deposition processes

The National Technology Roadmap for Semiconductors indicates that new metal and dielectric films are required for future semiconductor technology generations (130 nm and beyond). Both the film material type and device geometry result in the need for advanced CVD processes to produce the films. These processes will utilize metal organic (MOCVD), metal halide, and other precursors for the CVD reaction. These new precursor materials present a challenge in determining how to handle process emissions. Point of use emissions control was determined to be necessary to minimize the overall environmental, health and safety impacts of the precursors. Selection of a point of use device was based largely on minimizing personnel exposure that could occur during normal maintenance activities. Motorola has evaluated point-of-use abatement technologies and has determined that a high temperature dry bed scrubber, known as the Edwards gas reactor column (GRC), is a potential candidate for abatement of process emissions from MOCVD and metal halide CVD processes. This evaluation was based on CVD processes using precursors widely known in literature as candidate materials for new metal and dielectric films. This scrubber is equipped with air injection capability to ensure destruction of organic ligands present in both unreacted precursor and CVD process by-products. The scrubber bed material is capable of removing halides, such as Cl and Br, to prevent emissions of acid gases from the process. The bed material is also capable of removing the metal portion of unreacted precursor to prevent deposition further down the exhaust stream.