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US 12,451,321 B2Granted
Apparatus for obtaining optical measurements in a charged particle apparatus
AssigneeASML Netherlands B.V.
InventorsJan-Gerard Cornelis Van Der Toorn, Zhong-wei Chen
Life of this patent
Estimating the term…
Abstract
A charged particle inspection system may include a shielding plate having an aperture or more than one aperture, for example, to permit additional inspection by an additional instrument requiring a line of sight to the area of interest. A field shaping element, such as a window element or a raised rim, is placed at the aperture to prevent or reduce a component of an electric field.
Claims16
An article, comprising:
- a substantially planar plate comprising an electrically conductive material and structure defining a through aperture, the through aperture configured to be positioned above a conductive surface of a wafer stage;
- and
- a field shaping element positioned at the through aperture, the field shaping element being configured to counteract effects of the through aperture on an electric field near the substantially planar plate to minimize or prevent a component of the electrical field from being tangential to the conductive surface of the wafer stage, the field shaping element being electrically conductive and transmissive to light.
Dependencies are inferred from the claim text.