Method for evaluating impurity concentrations in epitaxial reagent gases

Abstract

A method for evaluating the concentration of impurities in gases used in depositing an epitaxial layer on a semiconductor substrate. The method includes processing a semiconductor substrate of known impurity levels in an epitaxial reactor, and measuring the impurity levels after epitaxial processing by drawing together at least a portion of the impurities and measuring the concentration of impurities that were drawn together. In one embodiment of the invention, a gettering layer is formed adjacent one or more surfaces of the substrate to getter impurities from the substrate into the gettering layer. The impurity concentration of the gettering layer is then measured and the results are used to determine at least a range of impurity concentrations that were transferred to the substrate from the epitaxial susceptor.

Dependencies are inferred from the claim text.