Title:
DETECTOR FOR MASK PATTERN
Document Type and Number:
Japanese Patent JPS57136322
Kind Code:
A
Abstract:
PURPOSE:To prevent the detection of a minute defect formed onto a mask, and to simplify the mask detector by conducting illumination by a diffused light by using a diffusion filter for the mask pattern. CONSTITUTION:Beams emitted from a light source 2 are collected by a condenser lens 3, and beams changed into the diffused lights by the diffusion filter 13 are illuminated to the mask to be inspected 1. The transmitted light of the mask 1 is passed through an imaging lens 4, and imaged onto the imaging surface of a photosensor 5. Accordingly, voltage to proper reference voltage is compared and changed into binary because the output voltage of the sensor corresponding to a minute transparent section in an opaque wide region is slightly smaller than a large transparent section and the voltage of a minute opaque section in a transparent wide region is slightly larger than a large opaque section. Consequently, the minute defect section cannot be detected.
Inventors:
TSUKAZAKI KOUICHI
Application Number:
JP2155581A
Publication Date:
August 23, 1982
Filing Date:
February 18, 1981
Export Citation:
Assignee:
HITACHI LTD
International Classes:
G01N21/88; G01B11/24; G01N21/956; G03F1/00; G03F1/84; H01L21/027; H01L21/66; (IPC1-7): G01B11/24
Domestic Patent References:
| JPS4940658A | 1974-04-16 | |||
| JPS5630724A | 1981-03-27 |