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Extraneous substance inspection method and apparatus
| Details |
Inventors: Nakamura, Hisato; Watanabe, Tetsuya; Morishige, Yoshio;
Assignee: Hitachi Electronics Engineering Co., Ltd. (Tokyo, JP)
Primary Examiner: Gonzalez; Frank
Assistant Examiner: Smith; Zandra V.
Attorney, Agent or Firm: Fay, Sharpe, Beall, Fagan, Minnich & McKee
In the present invention, an extraneous substance inspection optical system having an extraneous inspection area of a predetermined scanning width in subscanning direction of a matter to be inspected is positioned in such a manner that the extraneous substance inspection area at a moment when the matter to be inspected is started to move in main scanning direction is arranged at a position in the main scanning direction corresponding to a head portion of the matter to be inspected; the matter to be inspected is moved in the main scanning direction to be subjected to a forward scanning for the matter to be inspected to thereby detect possible extraneous substances in the extraneous inspection area; and the matter to be inspected is rotated by 180.degree. after completing the forward scanning, then the matter to be inspected is moved in the direction opposite to the forward scanning to be subjected to a backward scanning, to thereby detect possible extraneous substances in the extraneous substance inspection area. |
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DETAILED DESCRIPTION An object of the present invention is to provide an extraneous substance inspection method in which a moving range of an inspection table is halved to about two times of the diameter of a wafer to thereby reduce the size of the apparatus therefor as well as enhance the inspection efficiency thereof.
Another object of the present invention is to provide an extraneous substance inspection apparatus in which the size of an inspection table is limited to thereby reduce the size of the apparatus as well as enhance the inspection efficiency thereof.
An extraneous substance inspection method which achieves the above object is characterized, in that the method comprises the steps of: positioning an extraneous substance inspection optical system having an extraneous inspection area of a predetermined scanning width in subscanning direction of a matter to be inspected in such a manner that the extraneous substance inspection area at a moment when the matter to be inspected is started to move in main scanning direction is arranged at a position in the main scanning direction corresponding to a head portion of the matter to be inspected; moving the matter to be inspected in the main scanning direction to perform a forward scanning for the matter to be inspected; rotating the matter to be inspected by 180.
degree.
after completing the forward scanning; then moving the matter to be inspected in the direction opposite to the forward scanning to perform a backward scanning, whereby possible extraneous substances in the respective extraneous substance inspection areas are detected.
Further, an extraneous substance inspection apparatus according to the present invention is characterized, in that the apparatus comprises: an extraneous substance inspection optical system having an extraneous inspection area of a predetermined scanning width in subscanning direction of a matter to be inspected and positioned in such a manner that the extraneous substance inspection area at a moment when the matter to be inspected is started to move in main scanning direction is arranged at a position in the main scanning direction corresponding to a head portion of the matter to be inspected; a moving and rotating mechanism which mounts the matter to be inspected thereon, moves reciprocatively the matter to be inspected in main scanning direction and rotates the matter to be inspected by substantially 180
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