Defect inspection method and device using same
View Patent ↗A defect inspection device inspecting a sample includes a movable table on which the sample as an inspection object and a pattern chip are mounted, an illumination light irradiation unit which irradiates a surface of the sample or a surface of the pattern chip with linearly-formed illumination light, a detection optical system section where a plurality of detection optical systems are disposed at a plurality of positions above the table and which detect images of scattered light generated from the sample, and a signal processing unit which processes detected signals to detect a defect of the sample surface, and a plurality of repeating patterns for generating the scattered light according to positions of the objective lenses of the plurality of detection optical systems of the detection optical system section when the linearly-formed illumination light is irradiated by the illumination light irradiation unit are periodically formed in the pattern chip.
1. A defect inspection device for inspecting a sample, comprising:
a movable table on which the sample as an inspection object and a pattern chip with periodic patterns are mounted;
an illumination optical system section which irradiates a surface of the sample or a surface of the pattern chip mounted on the table with linearly-formed illumination light;
a detection optical system section provided with a plurality of detection optical systems which respectively focus scattered light generated from the sample or the pattern chip on an image sensor and detect an image of the scattered light; and
an image plane observation camera provided on at least one of the detection optical systems which are disposed on the detection optical system section,
wherein said detection optical system section is configured to inspect the sample by performing an image-focusing correlation among the pattern chip surface, a focus of the illumination light, and respective image sensors of the plurality of detection optical systems disposed on the detection optical system section is established by
positioning the pattern chip with a height where a height of a focal plane of an objective lens of the respective detection optical systems is coincident with a surface height of the pattern chip calculated by the image plane observation camera;
focus-adjusting the illumination optical system section and position-aligning a short axial direction of the linearly-formed illumination light using the image plane observation camera; and
position-aligning the respective image sensors of the plurality of detection optical system section to an optical axis direction and to the short axial direction of the linearly-formed illumination light.
2. The defect inspection device according to claim 1 , wherein the image plane observation camera is a two-dimensional camera.
3. The defect inspection device according to claim 1 ,
wherein at the step of position-aligning the respective image sensors of the plurality of detection optical systems disposed on the detection optical system section to the short axial direction of the linearly-formed illumination light, a slit thinner in width than a short axis of the image of the scattered light generated from the sample or the pattern chip which is irradiated with the linearly-formed illumination light and detected by the image sensor is arranged in front of the image sensor.
4. The defect inspection device according to claim 1 , wherein plural kinds of patterns are formed on the pattern chip.
5. A defect inspection method for inspecting a sample, comprising:
irradiating, using an illumination optical system section, a surface of the sample or a surface of the pattern chip mounted on a movable table with linearly-formed illumination light;
focusing scattered light generated from the sample or the pattern chip using a detection optical system section provided with a plurality of detection optical systems each of which respectively focus said scattered light generated from the sample or the pattern chip on an image sensor;
detecting an image of the scattered light; and
inspecting the sample using an image plane observation camera provided on at least one of the detection optical systems which are disposed on the detection optical system section,
wherein said inspecting further comprises performing an image-focusing correlation among the pattern chip surface, a focus of the illumination light, and respective image sensors of the plurality of detection optical systems disposed on the detection optical system section is by performing
a step of positioning the pattern chip with a height where a height of a focal plane of an objective lens of the respective detection optical systems is coincident with a surface height of the pattern chip calculated by the image plane observation camera;
a step of focus-adjusting the illumination optical system section and position-aligning a short axial direction of the linearly-formed illumination light by the image plane observation camera; and
a step of position-aligning the respective image sensors of the plurality of detection optical system section to an optical axis direction and to the short axial direction of the linearly-formed illumination light.
6. The defect inspection method according to claim 5 , wherein the image plane observation camera is a two-dimensional camera.
7. The defect inspection method according to claim 6 ,
wherein the step of position-aligning the respective image sensors of the plurality of detection optical systems disposed on the detection optical system section to the short axial direction of the linearly-formed illumination light, further comprises forming a slit thinner in width than a short axis of the image of the scattered light generated from the sample or the pattern chip which is irradiated with the linearly-formed illumination light and detected by the image sensor, and
wherein the slit is arranged in front of the image sensor.
8. The defect inspection method according to claim 7 , further comprising forming plural kinds of patterns on the pattern chip.