Filter for projection photolithographic system
AssigneeSharp Kabushiki Kaisha
InventorsTakashi Fukushima, Takashi Sugihara, Junkou Takagi
Life of this patent
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Abstract
A filter for use in a projection photolithographic system comprising: a circular light-impervious part for screening substantially 100% on the pupil of a projection lens the 0th-order diffracted light of a pattern to be projected on a substrate; a ring-like translucent part concentrically contacting the periphery of the circular light-impervious part to transmit on the pupil part of the 0th-order diffracted light and the +1st- or the -1st-order diffracted light of the pattern; and a ring-like light-pervious part concentrically contacting the periphery of the ring-like translucent part to transmit substantially 100% on the pupil the .+-.1st-order diffracted light of the pattern.
Claims11
A filter for use in a projection photolithographic system comprising:
- a circular light-impervious part for screening substantially 100% on the pupil of a projection lens the 0th-order diffracted light of a pattern to be projected on a substrate of the projection photolithographic system;
- a ring-like translucent part concentrically contacting the periphery of the circular light-impervious part to transmit on the pupil of the projection lens part of the 0th-order diffracted light and the +1st- or the -1st-order diffracted light of the pattern to be projected on the substrate;
- and
- a ring-like light-pervious part concentrically contacting the periphery of the ring-like translucent part to transmit substantially 100% on the pupil of the projection lens the +1st- or the -1st-order diffracted light of the pattern to be projected on the substrate.
Dependencies are inferred from the claim text.