Abstract: A semiconductor device fabrication-use mask pattern inspection apparatus having an optical configuration adaptable for achievement of a Koehler illumination system using a light source high in spatial coherency is disclosed. This apparatus includes a laser light source, a beam expander which is disposed between the laser source and a mask for expanding laser light to form an optical path of collimated light rays, and a beam splitter placed in the collimated light ray optical path for splitting the optical path into two optical paths. In one of these paths, a transmissive illumination optics is placed which irradiates transmission light onto the mask; in the other path, a reflective illumination optics is placed for irradiation of reflected light onto the mask. A pattern image of this mask is detected by a photosensitive device to generate a detected pattern image, which is sent to a comparator for comparison with a fiducial image thereof.

Abstract: A device for measuring the intensity of incoming light is disclosed. This device includes a rotatable light blocking unit which interrupts incident signal light at short regular intervals. The device also includes a light source which emits certain light different from the signal light while the signal light is interrupted by the block unit, and a measurement unit for measuring intensity values of the signal light and the certain light. A correction unit is provided for correcting the measured signal light intensity based on the certain light intensity. A calculator unit calculates a correction value through comparison of the intensity of the certain light to a reference value. The correction unit uses this correction value to correct the signal light intensity.

Abstract: The mask defect inspection apparatus including an illumination optical system for illuminating a mask on which a pattern is formed; an objective lens facing the mask; at least a pair of detection optical systems having a detection sensor for obtaining an image of the pattern, respectively, and which receive illumination light from illumination areas different from each other through the objective lens, respectively; and focusing changing means for changing a position of focusing between sites of the pattern in a film-thickness direction of the mask and the pattern images obtained by the detection sensors, such that the pattern images obtained by the detection sensors are changed corresponding to the film-thickness direction of the mask.

Abstract: A pattern inspecting method, comprising preparing a sample having a first and a second inspection regions and an imaging device having a plurality of pixels, scanning the first inspection region to a first direction using the imaging device to obtain a first measurement pattern representing at least parts of the first inspection region, scanning the second inspection region to the first direction using the imaging device to obtain a second measurement pattern representing at least parts of the second inspection region, comparing the first measurement pattern and the second measurement pattern with each other to determine presence or absence of a defect formed on the sample, and controlling a scanning condition for scanning a pattern of the second inspection region by the imaging device so as to keep the same with the scanning condition when the pattern of the first inspection region is scanned by the imaging device.

Abstract: In a defect inspecting apparatus, an illumination optical system illuminate a mask having a patterned surface, the optical beam passing through the mask is split into two beam components which is guided in first and second image pickup sensors. The pickup sensors has first and second pickup fields on the patterned surface, which pick up first and second parts of the mask image. The first and second pickup fields are parallel to each other and displaced from each other by (2n+1)×d/2 in the longitudinal direction thereof, where d denotes a longitudinal dimension of each pixel image in the first and second pick up fields and n denotes an integer equal to or larger than 0. The first and second parts of the mask image are merged to form a pattern image, and a defect in the mask is detected on the basis of the pattern image.

Abstract: A device for measuring the intensity of incoming light is disclosed. This device includes a rotatable light blocking unit which interrupts incident signal light at short regular intervals. The device also includes a light source which emits certain light different from the signal light while the signal light is interrupted by the block unit, and a measurement unit for measuring intensity values of the signal light and the certain light. A correction unit is provided for correcting the measured signal light intensity based on the certain light intensity. A calculator unit calculates a correction value through comparison of the intensity of the certain light to a reference value. The correction unit uses this correction value to correct the signal light intensity.

Abstract: A defect inspection apparatus includes an illumination optical system which sets a transmission illumination region and a reflection illumination region on an inspection target surface of a mask, first and second imaging units having first and second visual fields which are set on the inspection target surface, an imaging optical system that provides images, which are present on the first and second visual fields, on the first and second imaging units, a defect detection unit which detects a defect of the mask on the basis of the images provided on the first and second imaging units, and a control unit which controls a positional relationship between setting positions of the transmission illumination region and the reflection illumination region and setting positions of the first and second visual fields.

Abstract: An automatic focusing apparatus comprises a stage holding a substrate, an objective lens disposed facing the substrate surface, an illumination optics illuminating the substrate surface with a spotted light beam from an oblique direction, a photodetector detecting reflected light from the substrate surface, a position detection circuit detecting a vertical position of the substrate surface from an electric signal obtained from the photodetector to output a position signal, a correction circuit monitoring the position signal in real time and subtracting a surplus exceeding a signal change corresponding to a surface shape change of the substrate from the position signal, when a change amount per unit time of the position signal exceeds a predetermined level and outputting a corrected position signal, and a stage control circuit controlling the vertical position of the stage based on the corrected position signal.

Abstract: In a defect inspecting apparatus, an illumination optical system illuminate a mask having a patterned surface, the optical beam passing through the mask is split into two beam components which is guided in first and second image pickup sensors. The pickup sensors has first and second pickup fields on the patterned surface, which pick up first and second parts of the mask image. The first and second pickup fields are parallel to each other and displaced from each other by (2n+1)×d/2 in the longitudinal direction thereof, where d denotes a longitudinal dimension of each pixel image in the first and second pick up fields and n denotes an integer equal to or larger than 0. The first and second parts of the mask image are merged to form a pattern image, and a defect in the mask is detected on the basis of the pattern image.

Abstract: In a defect inspecting apparatus, a differential interference optical system forms a differential interference image which is produced from an optical interference of images in a predetermined direction, the images corresponding to inspecting parts of a pattern formed on a mask. A control part varies the predetermined direction so as to cause the differential interference optical system to produce another differential interference image. An image pickup sensor picks up the differential interference images in accordance with the variation of the predetermined direction. A defect detecting unit detects a defect in the pattern formed on the mask from comparing the differential interference images with reference images, respectively.

Abstract: The mask defect inspection apparatus including an illumination optical system for illuminating a mask on which a pattern is formed; an objective lens facing the mask; at least a pair of detection optical systems having a detection sensor for obtaining an image of the pattern, respectively, and which receive illumination light from illumination areas different from each other through the objective lens, respectively; and focusing changing means for changing a position of focusing between sites of the pattern in a film thickness direction of the mask and the pattern images obtained by the detection sensors, such that the pattern images obtained by the detection sensors are changed corresponding to the film-thickness direction of the mask.

Abstract: A mask-defect inspection apparatus including a plurality of illumination optical systems (2) for illuminating different areas (14a, 14b) on a mask (4) on which a pattern (6) is formed, an objective lens (OL) disposed to face the mask, and at least a pair of detection optical systems (15, 16) each having a detection sensor (17, 19) to form an image of the pattern and for receiving illumination light from each of the different areas through the objective lens, each of the detection optical systems having a mechanism (13a, 13b) for adjusting an angle of an aperture.

Abstract: A pattern inspection apparatus includes a pulse laser light source sequentially generating pulse laser light, an illumination optics applying the pulse laser light onto a mask substrate, an imaging optics collecting light from the mask substrate to form an image thereof, an area sensor sensing the image of the mask substrate obtained by the optics in a rectangular area unit, a comparator comparing image data acquired by the area sensor with previously prepared reference data to detect a defect of a pattern, a stage driving apparatus two-dimensionally scanning a stage having the mask substrate placed thereon, and a stage position detector detecting a position of the stage. With the above configuration, it is possible to efficiently inspect the surface of the mask substrate by adequately setting the moving speed of the mask substrate and the sensing timing of the sensing apparatus.

Abstract: An automatic focusing apparatus comprises a stage holding a substrate, an objective lens disposed facing the substrate surface, an illumination optics illuminating the substrate surface with a spotted light beam from an oblique direction, a photodetector detecting reflected light from the substrate surface, a position detection circuit detecting a vertical position of the substrate surface from an electric signal obtained from the photodetector to output a position signal, a correction circuit monitoring the position signal in real time and subtracting a surplus exceeding a signal change corresponding to a surface shape change of the substrate from the position signal, when a change amount per unit time of the position signal exceeds a predetermined level and outputting a corrected position signal, and a stage control circuit controlling the vertical position of the stage based on the corrected position signal.

Abstract: A pattern inspecting method, comprising preparing a sample having a first and a second inspection regions and an imaging device having a plurality of pixels, scanning the first inspection region to a first direction using the imaging device to obtain a first measurement pattern representing at least parts of the first inspection region, scanning the second inspection region to the first direction using the imaging device to obtain a second measurement pattern representing at least parts of the second inspection region, comparing the first measurement pattern and the second measurement pattern with each other to determine presence or absence of a defect formed on the sample, and controlling a scanning condition for scanning a pattern of the second inspection region by the imaging device so as to keep the same with the scanning condition when the pattern of the first inspection region is scanned by the imaging device.

Abstract: A specimen surface level adjusting method used in a pattern inspecting apparatus for inspecting a pattern on a specimen surface on the basis of a detected image obtained by projecting inspecting light onto the specimen surface, the specimen surface level adjusting method comprising projecting level measuring light onto the specimen surface, detecting the position of the measuring light reflected on the specimen surface, calculating the level of the specimen surface on the basis of the position of the optical axis, adjusting the level of the specimen surface so that the calculated level may be held within the depth of focus of a pattern inspecting optical system, detecting the intensity of the reflected light, and fixing the specimen surface to a reference level, if the intensity is less than a specific threshold value.

Abstract: A pattern inspection apparatus includes a pulse laser light source sequentially generating pulse laser light, an illumination optics applying the pulse laser light onto a mask substrate, an imaging optics collecting light from the mask substrate to form an image thereof, an area sensor sensing the image of the mask substrate obtained by the optics in a rectangular area unit, a comparator comparing image data acquired by the area sensor with previously prepared reference data to detect a defect of a pattern, a stage driving apparatus two-dimensionally scanning a stage having the mask substrate placed thereon, and a stage position detector detecting a position of the stage. With the above configuration, it is possible to efficiently inspect the surface of the mask substrate by adequately setting the moving speed of the mask substrate and the sensing timing of the sensing apparatus.