Inspection System for Particulate Contamination
Original Publication Date: 1978-Apr-01
Included in the Prior Art Database: 2005-Feb-20
An on-location particulate contamination detection tool is described. The tool features 360-degree radial illumination from 30 point sources on each of two tiers (see the figure). Each light tier is switchable, providing a choice of either 45-degree or 5-degree incident lighting to accommodate the various surfaces being inspected. (Wafer surfaces varying from blanket metal to personalization can be inspected.) Reflected light is captured by the light cap and a conical trap below the wafer plane. Light scattered from particulates is detected through the center of the unit normal to the product surface.