Projection aligner
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorEiji Tsukuda
Life of this patent
Estimating the term…
Abstract
The pattern of a spatial frequency filter including a liquid crystal element (1031-103n) is controlled without removing the filter from a projection lens system. Specifically, a spatial frequency filter (103) is disposed at the pupil surface in a projection lens system (10). A means for controlling the spatial frequency filter (103) includes a liquid crystal element controller (15b) and a filter information storage (16b). A pattern required for the spatial frequency filter (103) is transferred from the filter information storage (16b) to the liquid crystal controller (15b). The transmittance and phase shift of the spatial frequency filter (103) are previously designed by simulation, for example. Based on these data, an aspect of applying a voltage to the liquid crystal element (1031-103n) is stored in the filter information storage (16b).
Claims14
A projection aligner, comprising:
- a projection lens system through which light passing through a photomask passes on a way to an object to be processed, said projection lens system, including,
- a lens, and
- a spatial frequency filter having at least one liquid crystal element and projecting light passed through said photomask onto said object to be processed;
- and
- a liquid crystal controller that controls at least one of transmittance and refractive index of said liquid crystal element,
- wherein said spatial frequency filter is provided in a position closer to said object to be processed than said lens.
A projection aligner comprising:
- a photomask having at least one liquid crystal element;
- and
- a liquid crystal element controller for controlling the transmittance and refractive index of said liquid crystal element.
A projection aligner, comprising:
- a photomask having at least a first liquid crystal element;
- a liquid crystal element controller for controlling the transmittance of said first liquid crystal element in a direction of light passing through said photomask;
- and
- a spatial frequency filter having at least a second liquid crystal element and configured to project light passed through said photomask onto an object to be processed.
Dependencies are inferred from the claim text.