Contamination control in gas delivery systems for MOCVD

Each of the elements of a gas distribution system potentially is a source of contamination in film growth reactors. A detailed technical understanding of the origin and properties of the most common contaminants, their fluctuations and their interaction with the different elements in the delivery system are essential to provide consistent high gas purity for device growth. Governing processes in the gas source, the delivery system, and purifiers were addressed with selected examples, along with approaches for integrated solutions. The examples include impurity fluctuation in NH3 as a function of the method of delivery, moisture outgassing from particle filters as a function of filter material and matrix gas, and low-level breakthrough in packed bed adsorbent-based purifiers as a result of transport and reaction rate limitations. [Copyright &y& Elsevier]