Abstract:
A lithographic apparatus has a support (S) that is provided with burls (BR) for holding an object (W). The support has been fabricated with a lithographic manufacturing method, e.g., a MEMS- technology, so as to create burls whose orientations or positions are individually electrically controllable.
Abstract:
A reluctance actuator assembly comprising a reluctance actuator, a flux sensor to measure a magnetic flux in a gap of the reluctance actuator, and a flux amplifier to drive an actuator coil of the reluctance actuator based on a flux set point and the flux measured by the flux sensor. A method comprising providing to the flux amplifier a flux setpoint, the flux setpoint comprising a time constant component and a sinusoidally varying component at an excitation frequency, measuring a force generated by the reluctance actuator in response to the flux setpoint, and calibrating the reluctance actuator assembly from the measured force.
Abstract:
A spectral purity filter is integrated with a collector optic (CO) in an EUV lithography apparatus. The element is coated on at least one surface (410) with a multilayer stack comprising a plurality of alternating material layers (for example Mo, Si) suitable for reflecting radiation of EUV wavelength. To manufacture the element, a substrate (402) is provided with a three-dimensional profile (410a, 412, 410b) on a scale much larger than the wavelength of EUV radiation. The multilayer stack is then applied as a series conformal coatings formed by atomic layer deposition on the substrate after formation of said profile. The profile, as reproduced in the MLM coating (310a, 312, 310b), forms a spectral purity filter. Unwanted radiation such as infrared radiation will be scattered or diffracted so that a reduced portion is reflected in the same direction as the reflected EUV radiation. The profile may be designed to form a phase grating, or a scattering texture.
Abstract:
A reluctance actuator assembly comprising a reluctance actuator, a flux sensor to measure a magnetic flux in a gap of the reluctance actuator, and a flux amplifier to drive an actuator coil of the reluctance actuator based on a flux set point and the flux measured by the flux sensor. A method comprising providing to the flux amplifier a flux setpoint, the flux setpoint comprising a time constant component and a sinusoidally varying component at an excitation frequency, measuring a force generated by the reluctance actuator in response to the flux setpoint, and calibrating the reluctance actuator assembly from the measured force.
Abstract:
A substrate holder for use in a lithographic apparatus, the substrate holder including: a main body having a surface; a plurality of burls projecting from the surface and having end surfaces to support a substrate; and a thin film stack on the main body surface and forming an electric component, the thin film stack having a conductive layer configured to distribute electrical charge substantially uniformly throughout a plane of the stack in which the conductive layer is positioned.