| 摘要 |
PURPOSE: Masking blades for stepper are provided to entirely form wafer edge shots and to improve a yield by improving a structure. CONSTITUTION: Masking blades for controlling an exposure region size comprise a left blade, a right blade, an upper blade, and a lower blade. At this point, the left and right blades respectively have an opening in the center portion. And the width(a) of the openings, the width(b) of the relatively protruded portions, and the depth(c) of the openings are respectively manufactured to have a bigger size than maximal exposure region, so that an exposure map of a wafer edge portion is improved by controlling the left and right blades so as to reduce a loss of a chip, thereby improving a yield and a through-put.
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