Mark P Plemmons

US Patent:

20050024632, Feb 3, 2005

Filed:

Jul 15, 2004

Appl. No.:

10/891835

Inventors:

Mark Plemmons - McKinney TX, US
Timothy Tiemeyer - Randolph MA, US

International Classification:

G01N021/88

US Classification:

356237100

Abstract:

A system and method of inspecting a semiconductor wafer that may be employed to detect and to characterize defects occurring on an edge of the wafer. The wafer inspection system includes an optical module for providing a light source to scan the wafer edge, a light channel detector for detecting light reflected from the wafer edge, and a processor and memory for converting detected signals to digital form, and for filtering and processing the digital data. The module includes a wafer edge scanning mechanism for projecting a collimated laser beam toward the wafer edge at a predetermined angle of incidence to scan the wafer edge for defects. The light channel detector detects light reflected from the wafer edge to obtain wafer edge data, which are applied to thresholds to determine the location of defects in the wafer edge.