Foreign matter inspection method and foreign matter inspection apparatus

Abstract

In a foreign matter inspection apparatus comprising: irradiating unit for irradiating inspection light to an inspection area of an article to be inspected; intensity detecting unit for detecting intensity of either reflected light or scattered light, which is generated from the inspection area by irradiating thereto the inspection light; position detecting unit for detecting a position of either the reflected light or the scattered light within the inspection area; and deciding unit for deciding whether or not a foreign matter is present within the inspection area; the foreign matter inspection apparatus is comprised of: display unit capable of displaying thereon both a threshold image in which the threshold value is indicated over an entire area of the inspection area, and a detection sensitivity image indicated by being converted from the threshold image.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram for schematically showing an arrangement of a foreign matter inspection apparatus according to a first embodiment of the present invention.

FIG. 2 is a explanatory diagram for explaining a scanning operation of an optical beam by the foreign matter inspection apparatus according to the first embodiment.

FIG. 3 is a diagram for illustratively representing one example as to a threshold image of a one-chip image according to the first embodiment.

FIG. 4 is a diagram for illustratively showing one example as to a detection sensitivity image of the one-chip image according to the first embodiment.

FIG. 5 is a diagram for illustratively indicating a foreign matter detection upper limit value setting screen for each of areas according to the first embodiment.

FIG. 6 is a diagram for schematically showing an arrangement of a foreign matter inspection apparatus according to a second embodiment of the present invention.

FIG. 7A and FIG. 7B are diagrams for illustratively representing a focusing operation when the foreign matter inspection apparatus according to the second embodiment of the present invention is shipped from a factory.

FIG. 8A to FIG. 8C are diagrams for illustratively showing a focus offset when a user handles a wafer equipped with a film, according to the second embodiment of the present invention.

FIG. 9A and FIG. 9B are diagrams for illustratively showing a focus offset when a user handles a wafer equipped with a pattern, according to the second embodiment of the present invention.

Claims

1. A foreign matter inspecting method for comparing intensity of either reflected light or scattered light, which is generated from an inspection area of an article to be inspected by scanning irradiation of inspection light, with a threshold value set to each of divided inspection areas so as to decide whether or not a foreign matter is present in said inspection area; wherein: both a threshold image in which said threshold value is indicated over an entire area of said inspection area, and a detection sensitivity image indicated by being converted from said threshold image can be displayed.

2. The foreign matter inspecting method as claimed in claim 1, wherein: an entire inspection area of a semiconductor wafer corresponding to said article to be inspected is inspected within 1 scanning operation irrespective of such a fact as to whether or not a wafer pattern is present.

3. The foreign matter inspecting method as claimed in claim 1, wherein: the inspection area is divided into a plurality of inspection areas based upon a sort of a chip formed on a semiconductor wafer corresponding to said article to be inspected, or such a fact as to whether or not the chip is present.

4. A foreign matter inspection apparatus comprising: an irradiating unit for irradiating inspection light to an inspection area of an article to be inspected;an intensity detecting unit for detecting intensity of either reflected light or scattered light, which is generated from said inspection area by irradiating thereto the inspection light;a position detecting unit for detecting a position of either said reflected light or said scattered light within the inspection area;a deciding unit for deciding whether or not a foreign matter is present within the inspection area; anda display unit capable of displaying thereon both a threshold image in which said threshold value is indicated over an entire area of said inspection area, and a detection sensitivity image indicated by being converted from said threshold image.

5. The foreign matter inspection apparatus as claimed in claim 4, wherein: an entire inspection area of a semiconductor wafer corresponding to the article to be inspected is divided into a plurality of inspection areas based upon a sort of a chip thereof, or such a fact as to whether or not the chip is present.

6. A foreign matter inspection method for irradiating inspection light to an article to be inspected which includes a wafer; for receiving light which is reflected, or scattered from said article to be inspected; and for inspecting whether or not a foreign matter present on a surface of said article to be inspected based upon intensity of the received light; wherein: a focal point offset is adjusted in such a manner that the intensity of said received light is emphasized with respect to such a fact as to whether or not a wafer pattern formed on said article to be inspected is present, another fact as to whether or not a film is present, a material of the film, and a thickness of the film.

7. The foreign matter inspection method as claimed in claim 6, wherein: an entire inspection area of said wafer corresponding to said article to be inspected is inspected within 1 scanning operation of said inspection light irrespective of such a fact as to whether or not a wafer pattern is present.

8. A foreign matter inspection apparatus comprising: an irradiating unit for irradiating inspection light to an article to be inspected which includes a wafer;a light intensity detecting unit for receiving light which is reflected, or scattered from a surface of said article to be inspected so as to detect intensity of the detected light;a foreign matter deciding unit for inspecting, or deciding whether or not a foreign matter is present on the surface of said article to be inspected based upon light intensity data detected by said light intensity detecting unit;a stage for mounting thereon said article to be inspected;an upper/lower position varying unit for varying upper/lower positions of said article to be inspected by moving said stage along upper/lower directions; anda surface height position detecting unit for detecting a surface height position of said article to be inspected; wherein:a focal point offset is adjusted in such a manner that the intensity of the light received by said light intensity detecting unit is emphasized.

9. A foreign matter inspection apparatus comprising: an irradiating unit for irradiating inspection light to an article to be inspected which includes a wafer;a light intensity detecting unit for receiving light which is reflected, or scattered from a surface of said article to be inspected so as to detect intensity of the detected light;a foreign matter deciding unit for inspecting, or deciding whether or not a foreign matter is present on the surface of said article to be inspected based upon light intensity data detected by said light intensity detecting unit;a stage for mounting thereon said article to be inspected;an upper/lower position varying unit for varying upper/lower positions of said article to be inspected by moving said stage along upper/lower directions; anda surface height position detecting unit for detecting a surface height position of said article to be inspected; wherein:said surface height detecting unit includes two sets of detectors, the detection center positions of which are different from each other along the upper/lower directions of said article to be inspected; andwhile said stage is moved along the upper/lower directions so as to acquire maximum values detected by said two detectors respectively, said stage is moved along the upper/lower directions in such a manner that a focal point of said light intensity detecting unit is focused on an intermediate point between two points indicative of said two maximum detected values so as to adjust a focal point offset.

10. The foreign matter inspection apparatus as claimed in claim 9 wherein: in the case where a wafer equipped with a film is inspected, when a surface of the wafer under the film is inspected, the focal point offset is adjusted in such a manner that the focal point of said light intensity detecting unit is located at a position of an upper side from said intermediate point.

11. The foreign matter inspection apparatus as claimed in claim 10 wherein: in said focal point offset adjustment, such a point that intensity of the light received by said light intensity detecting unit becomes maximum is selected.

12. The foreign matter inspection apparatus as claimed in claim 9 wherein: when a wafer equipped with a pattern is inspected, the focal point offset is adjusted in such a manner that the focal point of said light intensity detecting unit is located at a position of an upper side from said intermediate point.

13. The foreign matter inspection apparatus as claimed in claim 12 wherein: in said focal point offset adjustment, such a point that intensity of the light received by said light intensity detecting unit becomes maximum is selected.

14. The foreign matter inspection apparatus as claimed in claim 9 wherein: while said article to be inspected is maintained at a height position where said focal point offset adjustment is carried out, the stage is moved along a horizontal direction of longitudinal/lateral directions so as to scan said inspection light.