Atmospheric molecular contamination control with local purging

[0023] Reference will now be made in detail to the disclosed subject matter which is illustrated in the accompanying drawings.

[0024] Usually refer to Figures 1A to 3 , describing a system and method for locally decontaminating a portion of the surface of a wafer according to the present invention. Optical systems are commonly used to measure or analyze the physical properties of thin films formed on substrates commonly used in semiconductor manufacturing, such as silicon wafers. Atmospheric Molecular Contamination (“AMC”), such as hydrocarbons and other contaminants, tends to accumulate on the surface of the wafer and prevent the optical system from obtaining accurate information about the physical properties of one or more wafers being measured or analyzed by the optical system. information. The present invention is directed to a system for preventing AMC from accumulating on the surface of a wafer by locally purging at least a portion of the surface of the wafer with a...