In some embodiments, the present disclosure relates to a process tool that includes a lithography apparatus arranged over a wafer chuck and an immersion hood apparatus laterally around the lithography apparatus. The lithography apparatus includes a photomask arranged between a light source and a lens. The immersion hood apparatus comprises input piping, output piping, and extractor piping. The input piping is arranged on a lower surface of the immersion hood apparatus and configured to distribute a liquid between the lens and the wafer chuck. The output piping is arranged on the lower surface of the immersion hood apparatus and configured to contain the liquid arranged between the lens and the wafer chuck. The extractor piping is arranged on an outer sidewall of the immersion hood apparatus and configured to remove any liquid above the wafer chuck that is outside of the immersion hood apparatus.

An immersion lithographic apparatus having a fluid handling structure, the fluid handling structure configured to confine immersion fluid to a region and including: a meniscus controlling feature having an extractor exit on a surface of the fluid handling structure; and a gas knife system outwards of the extractor exit and including passages each having an exit, the passages having a plurality of first passages having a plurality of corresponding first exits on the surface, and a plurality of second passages having a plurality of corresponding second exits outwards of the first exits on the surface, wherein the surface faces and is substantially parallel to a top surface of a substrate during exposure, and the first exits and the second exits are arranged at a greater distance from the substrate than the extractor exit.

A difficulty of contamination interfering with a grid plate positional measurement system is addressed. In one embodiment contamination is prevented from coming into contact with the grating or the sensor. In an embodiment, surface acoustic waves are used to detach contamination from a surface of the grating or sensor.

Embodiments of a drain in a lithographic projection apparatus are described that have, for example, a feature which reduces inflow of gas into the drain during a period when no liquid is present in the drain. In one example, a passive liquid removal mechanism is provided such that the pressure of gas in the drain is equal to the ambient gas pressure and in another embodiment a flap is provided to close off a chamber during times when no liquid needs removing.

A substrate holder for a lithographic apparatus has a main body having a thin-film stack provided on a surface thereof. The thin-film stack forms an electronic or electric component such as an electrode, a sensor, a heater, a transistor or a logic device, and has a top isolation layer. A plurality of burls to support a substrate are formed on the thin-film stack or in apertures of the thin-film stack.

A wavelength control method of a laser apparatus includes sequentially obtaining target wavelength data of a pulse laser beam, sequentially saving the target wavelength data, sequentially measuring a wavelength of the pulse laser beam to obtain a measured wavelength, calculating a wavelength deviation using the measured wavelength and the target wavelength data at a time before a time when the measured wavelength is obtained, and feedback-controlling the wavelength of the pulse laser beam using the wavelength deviation.

A substrate support for supporting a substrate in a lithographic apparatus, the substrate support including: a support body configured to support the substrate; a main body separate from the support body and configured to support the support body, the main body including a thermal conditioner configured to thermally condition the main body and/or support body and/or substrate; and an extractor body surrounding the main body and the support body, the extractor body having an extraction channel configured to extract fluid from near a peripheral part of the substrate.

A hydrophobic membrane structure includes: a color-changing layer, and a hydrophobic layer covering the surface of the color-changing layer. The color of an area of the color-changing layer in contact with the liquid changes to form a color-changing area, when the color-changing layer comes into contact with liquid.

A lithographic apparatus with a cover plate formed separately from a substrate table and means for stabilizing a temperature of the substrate table by controlling the temperature of the cover plate is disclosed. A lithographic apparatus with thermal insulation provided between a cover plate and a substrate table so that the cover plate acts as a thermal shield for the substrate table is disclosed. A lithographic apparatus comprising means to determine a substrate table distortion and improve position control of a substrate by reference to the substrate table distortion is disclosed.

A fluid handling structure for a lithographic apparatus configured to contain immersion fluid to a region, the fluid handling structure having, at a boundary of a space: at least one gas knife opening in a radially outward direction of the space; and at least one gas supply opening in the radially outward direction of the at least gas knife opening relative to the space. The gas knife opening and the gas supply opening both provide substantially pure CO.sub.2 gas so as to provide a substantially pure CO.sub.2 gas environment adjacent to, and radially outward of, the space.