Patent ID: 6969853
Filing Date: 2005-11-29
Classification: H01J

Abstract:
1. A pattern width measuring apparatus for measuring pattern width of a pattern formed on a wafer using an electron beam, comprising: an electron beam generating section for generating the electron beam; a deflector for scanning the pattern with the electron beam by deflecting the electron beam; an electrostatic lens for focusing the electron beam deflected by the deflector onto the wafer or the pattern; a first secondary electron detector and a second secondary electron detector provided above said electrostatic lens for detecting secondary electrons generated when the electron beam is irradiated on the wafer or the pattern through said electrostatic lens; a first edge detector for detecting position of a first edge of the pattern based on the quantity of the secondary electrons detected by said first secondary electron detector out of said first secondary electron detector and said second secondary electron detector; a second edge detector for detecting position of a second edge of the pattern based on the quantity of the secondary electrons detected by said second secondary electron detector out of said first secondary electron detector and said second secondary electron detector; and a pattern width computing section for computing pattern width of the pattern based on the position of the first edge and the position of the second edge detected by said first edge detector and said second edge detector.