David L Field

US Patent:

54669340, Nov 14, 1995

Filed:

Jan 18, 1995

Appl. No.:

8/374214

Inventors:

Brent L. Adams - Gibsonia PA
David J. Dingley - Salt Lake City UT
David P. Field - Pleasant Grove UT

International Classification:

G01N 23203

US Classification:

250307

Abstract:

An imaging apparatus (10) includes a scanning electron microscope (12) which is controlled to bombard numerous points (62) of a material sample (24) with an electron beam (18). Backscatter diffraction patterns are collected by an image collection system (26) which may include both a slower responding video camera (32) and a faster responding diode array (40). For a baseline point (62), an electron backscatter diffraction pattern collected at the video camera (32) is analyzed to identify representative pixels which reside along Kikuchi bands (78). Backscatter images from subsequent points (62) are rapidly compared (98) with the baseline to detect changes. When changes are not detected, EBSPs are not analyzed. When changes are detected, EBSPs are analyzed to generate new baselines. The resulting collection of analyzed EBSPs are processed (104) to identify microstructure attributes and to characterize defects (64).