Multiple detector system for specimen inspection using high energy backscatter electrons.

摘要

An inspection system employing high collection efficiency energy filtered backscatter electrons. At least two detectors (26, 28, 30) are positioned relative to the sample (128) at spaced locations. Each detector has a canister (122) with a fiberoptic bundle (44) mounted therein. A scintillator detector (60) is mounted at the end of the fiberoptic bundle. A ground grid (124) is mounted at an opening of the canister in axial alignment with the scintillator detector. An energy filter (56) is interposed between the scintillator detector and the ground grid. The energy filter is an electrostatic retarding potential grid to permit detection of only high energy backscatter electrons. The geometry of the detectors relative to the specimen together with the conical shape of the detector housing achieves maximum collection efficiency of the targeted electrons. <IMAGE>