Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
A high speed, high resolution optical scanner for objective focussing of laser light is used to optically identify contamination on patterned silicon wafers. This optical scanning system is an improvement over using large lenses to image the entire wafer at once for contamination detection. In Fig. 1, a microscope objective 1 similar to that used on a video disk player is mounted on one end of a rotating arm 2. Mirrors 3 and 4 are mounted on the arm that intersects both the rotation axis and the optical axis of the objective at 45 degrees. A glass pipe or tube 5 is coaxial with the objective. The upper end of this pipe 6 is cut, polished, and anti-reflection coated normal to the optical axis.