Determination of metals impurity concentrations in semiconductor gases

Monitoring metals concentration in semiconductor gases requires a variety of sampling techniques. The chemical and physical nature of the matrix gas are what determine which method is most appropriate. Due to the non-homogeneity of metals concentrations in the gases and the lack of information corresponding to the exact chemical composition of each metal impurity present, the extraction efficiency of sampling methods is difficult to verify. Therefore, the sampling methods are designed to capture the majority of metals contaminants whether in solid or vapor form. The focus of this paper is to review the current sampling techniques and analytical methods applied to metals determination in semiconductor gases.