Exposure apparatus exposes a substrate by irradiating the substrate with exposure light via a projection optical system and a liquid. The exposure apparatus is provided with a liquid immersion mechanism for supplying the liquid and recovering the liquid. The liquid immersion mechanism has an inclined surface, which is opposite to a surface of the substrate and is inclined with respect to the surface of the substrate, and a liquid recovering port of the liquid immersion mechanism is formed in the inclined surface. A flat portion is provided between the substrate and the projection optical system. A liquid immersion area can be maintained to be small.

A micro-optic cell design with randomly positioned lenslets is provided herein that uses statistical reconstruction of a micro-lens array. A method of making an optical element, which includes a micro-optic unit cell comprising one or more lenslets, is also disclosed.

Embodiments herein describe methods, devices, and systems for rupture detection and end-of-life monitoring of dynamic gas lock (DGL) membranes and pupil facet mirrors in lithographic apparatuses. A method for detecting rupture of a dynamic gas lock membrane in a lithographic apparatus includes illuminating the dynamic gas lock membrane with a measurement beam using a radiation source, in which the dynamic gas lock membrane is arranged between a wafer and projection optics of the lithography apparatus, and determining whether any radiation from the measurement beam is reflected from the dynamic gas lock membrane by using reflection collection optics, in which the reflection collection optics are arranged above the dynamic gas lock membrane. A rupture in the dynamic gas lock membrane is detected if no radiation is reflected from the dynamic gas lock membrane. If radiation is reflected from the dynamic gas lock membrane, the dynamic gas lock membrane is not ruptured.

An extreme ultraviolet light generation apparatus includes a first chamber, an EUV light concentrating mirror arranged in the first chamber and configured to concentrate extreme ultraviolet light generated at a first point in the first chamber onto a second point, a first planar mirror arranged on an optical path of the extreme ultraviolet light reflected by the EUV light concentrating mirror, a second chamber accommodating the first planar mirror, a flexible tube arranged between the first and second chambers, an alignment optical system arranged at the first chamber and configured to cause alignment light to be incident on the EUV light concentrating mirror, a detector arranged at the second chamber and configured to detect the alignment light reflected by the EUV light concentrating mirror, an actuator configured to change posture of the first planar mirror, and a processor configured to control the actuator based on output of the detector.

A method for maintaining a projection exposure apparatus comprising at least two modules and a reference element, wherein the modules are referenced to the reference element, comprises: removing a module; attaching a service module to or in the vicinity of the projection exposure apparatus; referencing the service module to the reference element of the projection exposure apparatus; and implementing a maintenance measure with the aid of the service module.

The present invention provides a fluid purging system (100) for an optical element (30), comprising a ring and a fluid supply system (40). The ring being formed of a body entirely surrounding the optical element, the ring defining a space (5) radially inwards thereof and adjacent to the optical element. The ring is formed by at least one first wall portion (10) and at least one second wall portion (20A;20B), wherein an average height of the first wall portion is greater than an average height of the second wall portion. The fluid supply system is positioned radially outwards of the ring and configured to supply fluid to pass over the at least one second wall portion to the space.

A laser apparatus may include, a first frame and a second frame, a sleeve through-hole provided in the second frame, a sleeve insertion hole provided in the first frame, a bolt, a positioning sleeve that is formed in an approximately cylindrical shape into which the bolt can be inserted and that positions the first frame and the second frame by passing through the sleeve through-hole and being inserted into the sleeve insertion hole, a nut that is provided in the first frame and into which the bolt is screwed, and a fall prevention unit that is provided in the second frame and that prevents the bolt and the positioning sleeve from falling.

A method for controlling a vibrating optical element of a lithographic system the optical element having a predetermined number of degrees of freedom comprises: detecting a number of displacements of the optical element, each displacement corresponding to a degree of freedom, wherein the number of detected displacements is larger than the number of degrees of freedom; for each displacement according to a degree of freedom, generating a sensor signal corresponding to a movement in a degree of freedom; wherein the optical element moves as a function of a rigid body transformation matrix, the optical element movement including a first type of movement and a second type of movement; and modifying the sensor signals as a function of a modified transformation matrix, wherein the modified transformation matrix at least partially reduces at least one eigen mode or resonance of one of the first type of movements or the second type of movements.

Provided is an interferometer system that irradiates an object to be measured with measuring light to thereby measure the position of the object to be measured. The interferometer system includes a laser light source; an interferometer configured to separate laser light emitted from an emission opening of the laser light source into the measuring light and reference light; and an optical path protecting member configured to surround an optical axis such that the laser light passes through the inside thereof and of which one opening is in contact with the emission opening.

An optical apparatus may include a housing having an opened front face, an optical unit freely movable into and out of an internal space of the housing through the front face, and a positioning portion disposed on a back side of the optical unit in the internal space. A base plate of the optical unit may include first and second convex portions disposed on a base end face of the base plate. The second convex portion may be disposed at a position different from the first convex portion in a width direction of the base plate. The positioning portion may include a V block having a V groove shape at a part contacting the first convex portion, and a flat block having a flat surface shape at a part contacting the second convex portion. The optical unit may be positioned in the internal space through the contact.