Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
156 words
Apparatus for detecting defects of an object having linear straight line features and nonlinear defects comprising: a coherent light source for emitting coherent light; an incoherent light source for emitting incoherent light; a first collimator for collimating said coherent light to a prescribed light thickness; a second collimator for collimating said incoherent light to a prescribed light thickness; means for irradiating coherent light passed through said first collimator and incoherent light passed through said second collimator on the same optical axis to said object; a transform lens for transforming the intensity distribution of permeated light or reflected light of said object into a Fourier-transform pattern; a spatial filter located on the Fourier-transform plane of said transform lens, and for preventing the passing of coherent light having information of said linear straight line features of said object; and means for projecting a coherent image and an incoherent image respectively passed through said spatial filter on one another.
Claim 2
Dependent Claim
156 words
Apparatus for detecting defects of an object having linear straight line features and nonlinear defects comprising: a coherent light source for emitting coherent light; an incoherent light source for emitting incoherent light; a first collimator for collimating said coherent light to a prescribed light thickness; a second collimator for collimating said incoherent light to a prescribed light thickness; means for irradiating coherent light passed through said first collimator and incoherent light passed through said second collimator on the same optical axis to said object; a transform lens for transforming the intensity distribution of permeated light or reflected light of said object into a Fourier-transform pattern; a spatial filter located on the Fourier-transform plane of said transform lens, and for preventing the passing of coherent light having information of said linear straight line features of said object; and means for projecting a coherent image and an incoherent image respectively passed through said spatial filter on one another.
Claim 3
Dependent Claim
17 words
Apparatus for detecting defects of an object as in claim 1 wherein said object is a photomask.
Claim 4
Dependent Claim
26 words
Apparatus for detecting defects of an object as in claim 1 wherein a color filter is located between said incoherent light source and said second collimator.
Claim 5
Dependent Claim
25 words
Apparatus for detecting the defects of an object according to claim 1, wherein: said coherent light source is a laser emitting red colored coherent light.
Claim 6
Dependent Claim
23 words
Apparatus for detecting the defects of an object according to claim 3 wherein: said color filter prevents the passing of red-colored incoherent light.
Claim 7
Dependent Claim
20 words
Apparatus for detecting the defects of an object according to claim 1 wherein: said irradiating means comprises a half mirror.
Claim 8
Dependent Claim
20 words
Apparatus for detecting the defects of an object according to claim 1, wherein: said irradiating means comprises a dichroic mirror.
Claim 9
Dependent Claim
32 words
Apparatus for detecting the defects of an object according to claim 1, wherein: said spatial filter is formed by a plurality of arm portions extending in predetermined directions from the center thereof.
Claim 10
Dependent Claim
41 words
Apparatus for detecting the defects of an object according to claim 1, wherein: said transform lens and said spatial filter are placed in a housing for an objective lens of a microscope, and projecting means comprising an ocular of said microscope.
Claim 11
Dependent Claim
29 words
Apparatus for detecting the defects of an object according to claim 9 wherein: means for illuminating said mask pattern by incoherent light through said spatial filter is further provided.