Position detecting method
AssigneeCanon Kabushiki Kaisha
InventorsTakehiko Suzuki, Satoru Oishi
Life of this patent
Estimating the term…
Abstract
There is provided a position detecting method for detecting a position of an object, on which an alignment mark including plural mark elements is formed. The method includes the steps of obtaining positional information indicative of each position of the plural mark elements, selecting positional information that has predetermined precision among plural pieces of positional information obtained by the obtaining step, and calculating the position of the object using the positional information that has the predetermined precision selected by the selecting step.
Claims10
A position detecting method for detecting a position of an object, on which an alignment mark including plural mark elements is formed, said method comprising the steps of:
- detecting positions of the plural mark elements and obtaining a predetermined mark element interval between the plural mark elements;
- calculating an offset between the predetermined mark element interval obtained by said obtaining step and an interval reference value of the predetermined mark elements which is calculated by a designed value of the alignment mark corresponding to the predetermined mark element interval;
- determining abnormality of the mark elements based on the offset;
- producing a position of the mark element determined to be abnormal by the determining step, from a position of the mark element that is determined normal;
- and
- calculating the position of the alignment mark using the position of the mark element that is determined normal by the determining step and the position of the mark element that is produced by the producing step.
Dependencies are inferred from the claim text.