Wafer pattern defect detection method and apparatus therefor
AssigneeKabushiki Kaisha Toshiba
InventorsMotosuke Miyoshi, Yuichiro Yamazaki
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Abstract
A scanning electron beam is formed as a rectangular electron beam. The electro-optical system which forms this rectangular beam has a rectangular-cathode light source and a quadrupole lens system. This rectangular beam is scanned in its short-axis (X-axis) direction by a deflection system while a stage is moved in its long-axis (Y-axis) direction to achieve scanning of the surface of the wafer under inspection. The rectangular beam corresponds to a number of circular beams arranged in a row. Therefore, pixel signals corresponding to a number of pixels equal to the aspect ratio of the rectangular beam (ratio of the length in the long-axis direction to the length in the short-axis direction) are simultaneously output.
Claims11
A wafer pattern defect detection apparatus, comprising:
- rectangular electron beam generation means having a multipole electrostatic lens for generating a rectangular electron beam from a rectangular electron source, the rectangular electron beam being of a size adjusted for the size of the pattern on a wafer under inspection, the rectangular electron beam being focused, by the multipole electrostatic lens, on the part of the wafer to be inspected;
- signal detecting means for detecting an electron signal which is generated from said wafer under inspection;
- and
- a defect detection means for detecting the presence of a defect inside wafer under inspection, by means of electron signal image data which is based on an output signal from said electron signal detection means.
A wafer pattern defect detection method comprising the steps of:
- outputting a rectangular electron beam from a rectangular electron source;
- focusing the rectangular electron beam by a multipole electrostatic lens on the surface of a wafer under inspection and detecting a secondary electron signal from the surface of the wafer under inspection;
- and
- generating secondary electron image data from said secondary electron signal and detecting defects on the surface of said wafer under inspection from said secondary electron image data.
Dependencies are inferred from the claim text.