Abstract: Method of and apparatus for repairing an optical element disposed in a vacuum chamber while the optical element is in the vacuum chamber. An exposed surface of the optical element is exposed to an ion flux generated by an ion source to remove at least some areas of the surface that have been damaged by exposure to the environment within the vacuum chamber. The method and apparatus are especially applicable to repair multilayer mirrors serving as collectors in systems for generating EUV light for use in semiconductor photolithography.

Abstract: Method of and apparatus for repairing an optical element disposed in a vacuum chamber while the optical element is in the vacuum chamber. An exposed surface of the optical element is exposed to an ion flux generated by an ion source to remove at least some areas of the surface that have been damaged by exposure to the environment within the vacuum chamber. The method and apparatus are especially applicable to repair multilayer mirrors serving as collectors in systems for generating EUV light for use in semiconductor photolithography.

Abstract: A reflective EUV optic such as a collector mirror configured as an array of facets that are spaced apart to form respective gaps between adjacent facets. The gaps are used as inlets for gas flow across one of the facets such that flow is introduced parallel to the optic surface. The facets can be made with offsets such that loss of reflective area of the EUV optic can be minimized. The gas facilitates removal of target material from the surface of the facets.

Abstract: Apparatus for and method of cleaning an electrically conductive surface of an optical element in a system for generating extreme ultraviolet radiation in which electrically conductive surface is used as an electrode for generating a plasma which cleans the surface.

Abstract: Disclosed is an EUV system in which a source control loop is established to maintain and optimize debris flux while not unduly affecting optimum EUV generation conditions. One or more temperature sensors, e.g., thermocouples may be installed in the vessel to measure respective local gas temperatures. The respective local temperature as measured by the one or more thermocouples can be used as one or more inputs to the source control loop. The source control loop may then adjust the laser targeting to permit optimization of debris generation and deposition while not affecting EUV production, thus extending the lifetime of the source and its collector.

Abstract: A device and method are disclosed in which a source material delivery system can be reoriented so that the path of the source material is not directly towards an irradiation region in operating conditions in which the path is expected to be unpredictable. A shroud provided to protect the flow of source material from being disrupted is segmented so with one part of the shroud being movable with respect to another part of the shroud so that the movable part can avoid interfering with the path of the source material when it is not directly towards the irradiation region.

Abstract: Disclosed is an EUV system in which a source control loop is established to maintain and optimize debris flux while not unduly affecting optimum EUV generation conditions. One or more temperature sensors, e.g., thermocouples may be installed in the vessel to measure respective local gas temperatures. The respective local temperature as measured by the one or more thermocouples can be used as one or more inputs to the source control loop. The source control loop may then adjust the laser targeting to permit optimization of debris generation and deposition while not affecting EUV production, thus extending the lifetime of the source and its collector.

Abstract: Optical element protection systems for protecting optical elements and particularly reflective optical elements from degradation of their optical properties in harsh environments such as the environment inside a vacuum chamber of an EUV light source. The systems include the uses of combinations of materials in various layers where the materials are chosen and the layers are configured and arranged to extend the lifetime of the optical element without compromising its optical properties.

Abstract: Disclosed is an EUV system in which a source control loop is established to maintain and optimize debris flux while not unduly affecting optimum EUV generation conditions. One or more temperature sensors, e.g., thermocouples may be installed in the vessel to measure respective local gas temperatures. The respective local temperature as measured by the one or more thermocouples can be used as one or more inputs to the source control loop. The source control loop may then adjust the laser targeting to permit optimization of debris generation and deposition while not affecting EUV production, thus extending the lifetime of the source and its collector.

Abstract: Disclosed is an EUV system in which a source control loop is established to maintain and optimize debris flux while not unduly affecting optimum EUV generation conditions. One or more temperature sensors, e.g., thermocouples may be installed in the vessel to measure respective local gas temperatures. The respective local temperature as measured by the one or more thermocouples can be used as one or more inputs to the source control loop. The source control loop may then adjust the laser targeting to permit optimization of debris generation and deposition while not affecting EUV production, thus extending the lifetime of the source and its collector.

Abstract: A device and method are disclosed in which a source material delivery system can be reoriented so that the path of the source material is not directly towards an irradiation region in operating conditions in which the path is expected to be unpredictable. A shroud provided to protect the flow of source material from being disrupted is segmented so with one part of the shroud being movable with respect to another part of the shroud so that the movable part can avoid interfering with the path of the source material when it is not directly towards the irradiation region.

Abstract: A carrier holds an extreme ultraviolet light source collector mirror. The carrier includes a front panel having an inner surface and an outer surface opposite the inner surface, and defining a through opening that has an edge having a plurality of scallops; a back panel having an inner surface that faces the front panel and an outer surface opposite the inner surface; and a plurality of posts that are configured to connect the back panel to the front panel and to sandwich a flat rim around the circular boundary of the collector mirror between the inner surface of one of the panels and flanges of the posts. The scallops are positioned around a circumference of the edge and being separated by arcs, where the arcs define a circle that has a diameter that is less than a diameter of the circular boundary of the reflective surface of the collector mirror.

Abstract: A device and method are disclosed in which gas is caused to flow parallel to a flow of source material to form a gas shroud. The gas shroud may protect flow of source material from being disrupted by a cross flow of gas. The gas shroud may also limit heating of a physical shroud through which the source material passes and limit accumulation of source material on the physical shroud by deforming a plasma bubble formed during irradiation of the source material so that the plasma bubble does not come too near the physical shroud. A device and method are also disclosed for establishing an additional transverse flow of gas so that the gas shroud does not cause source material contamination of an optic used to collect light generated during irradiation of the source material.

Abstract: Devices and methods for generating EUV light are disclosed. The device comprises an oscillator having an oscillator cavity length, Lo, and defining an oscillator path and a multi-pass optical amplifier coupled with the oscillator to establish a combined optical cavity including the oscillator path, the combined cavity having a length, Lcombined, where Lcombined=(N+x)*Lo, where “N” is an integer and “x” is a number between 0.4 and 0.6. The amplifier comprises a polarization discriminating optic inputting light traveling along a first beam path from the oscillator and having substantially a first linear polarization into the amplifier and outputting light having substantially a linear polarization orthogonal to the first polarization out of the amplifier along a second beam path.

Abstract: A reflective EUV optic such as a collector mirror configured as an array of facets that are spaced apart to form respective gaps between adjacent facets. The gaps are used as inlets for gas flow across one of the facets such that flow is introduced parallel to the optic surface. The facets can be made with offsets such that loss of reflective area of the EUV optic can be minimized. The gas facilitates removal of target material from the surface of the facets.

Abstract: Apparatus for and method of cleaning an electrically conductive surface of an optical element in a system for generating extreme ultraviolet radiation in which electrically conductive surface is used as an electrode for generating a plasma which cleans the surface.

Abstract: Free radicals that combine with debris that is created by converting a target mixture to plasma that emits EUV light are received at a first opening defined by a first end of a conduit, the conduit including a material that passes the free radicals and the conduit including a sidewall that extends away from the first opening and defines at least one other opening, the at least one other positioned to release the free radicals toward an element that accumulates the debris on a surface. The free radicals in the conduit are directed toward the at least one other opening. The free radicals are passed through the at least one other opening and to the surface of the element to remove the debris from the surface of the element without removing the element from the EUV light source.

Abstract: A system for an extreme ultraviolet (EUV) light source includes a radical transport system that includes one or more conduits, each of the one or more conduits comprising a sidewall, the sidewall comprising a linear portion and a second portion, the linear portion of the sidewall comprising a first end that defines a first opening, and the second portion of the sidewall comprising one or more openings from an interior of the conduit to an exterior of the conduit, where the second portion of at least one of the one or more conduits is positioned relative to a collector that is inside of a vacuum chamber of the EUV light source with a gap between the collector and the second portion; and a control system.

Abstract: A reflective EUV optic such as a collector mirror configured as an array of facets that are spaced apart to form respective gaps between adjacent facets. The gaps are used as inlets for gas flow across one of the facets such that flow is introduced parallel to the optic surface. The facets can be made with offsets such that loss of reflective area of the EUV optic can be minimized. The gas facilitates removal of target material from the surface of the facets.

Abstract: Method of temperature compensating a focusing system in which a temperature of a thermal lens compensation plate is regulated based on an optical absorption of the thermal lens compensation plate with optical absorption being determined based at least in part on an expected end-of-lifetime value for focus lens optical absorption. A value representative of cumulative time in use of the focusing systems is determined and the temperature of the thermal lens compensation plate is increased to a temperature based at least in part on said cumulative time in use.