William A. Syverson

Characterization of Surface Metal Particulate Contamination Using the Polysilicon Chemical Vapor Deposition Process

For many semiconductor wafer processes and, in particular, polysilicon chemical vapor deposition (CVD), metallic contamination is a known problem. Metallics can act as localized catalysts during the CVD process, which results in an accelerated, non-uniform polysilicon deposition that is “spike-like” in shape and appearance. These “spike” defects are known to cause interlevel electrical shorts in integrated circuits. With a 400-nm deposition, the spikes range from 0.25 to 2.0 μm in height and are often uniquely characteristic of the contamination from the metallic element tested.