Abstract: An object holder configured to support an object, the object holder comprising: a core body comprising a plurality of burls having distal ends in a support plane for supporting the object; an electrostatic sheet between the burls, the electrostatic sheet comprising an electrode sandwiched between dielectric layers; and a circumferential barrier for reducing outflow of gas escaping from space between the object and the core body.

Abstract: A method for reducing sticking of an object to a surface used in a lithography process includes receiving, at a control computer, instructions for a tool configured to modify the surface and forming, in a deterministic manner based on the instructions received at the control computer, a modified surface having a furrow and a ridge, wherein the ridge reduces the sticking by reducing a contact surface area of the modified surface. Another apparatus includes a modified surface that includes furrows and ridges forming a reduced contact surface area to reduce a sticking of an object to the modified surface, the ridges having an elastic property that causes the reduced contact surface area to increase when the plurality of ridges is elastically deformed.

Abstract: A method for reducing sticking of an object to a surface used in a lithography process includes receiving, at a control computer, instructions for a tool configured to modify the surface and forming, in a deterministic manner based on the instructions received at the control computer, a modified surface having a furrow and a ridge, wherein the ridge reduces the sticking by reducing a contact surface area of the modified surface. Another apparatus includes a modified surface that includes furrows and ridges forming a reduced contact surface area to reduce a sticking of an object to the modified surface, the ridges having an elastic property that causes the reduced contact surface area to increase when the plurality of ridges is elastically deformed.

Abstract: The present disclosure is directed to a modular wafer table and methods for refurbishing a scrapped wafer to manufacture the modular wafer table. The method comprises removing one or more burls from a surface of a wafer table; polishing the surface of the wafer table after removing the one or more burls to form a core module; forming a burl module having a plurality of burls thereon; and bonding the core module to the burl module.

Abstract: Systems, apparatuses, and methods are provided for manufacturing an electrostatic clamp. An example method can include forming a dielectric layer that includes a plurality of burls for supporting an object. The example method can further include forming an electrostatic layer that includes one or more electrodes. The example method can further include generating, using the electrostatic layer, an electrostatic force to electrostatically clamp the object to the plurality of burls in response to an application of one or more voltages to the one or more electrodes. In some aspects, a first magnitude of the electrostatic force in a first region of the dielectric layer can be different than a second magnitude of the electrostatic force in a second region of the dielectric layer. For example, the first magnitude and the second magnitude can be part of a linear, non-linear, or stepped (e.g., multi-level) electrostatic force gradient.

Abstract: A substrate table for supporting a substrate includes a surface and coarse burls. Each of the coarse burls includes a burl-top surface and fine burls. The coarse burls are disposed on the surface of the substrate table. The fine burls are disposed on the burl-top surface. The fine burls contact the substrate when the substrate table supports the substrate.

Abstract: Systems, apparatuses, and methods are provided for manufacturing a substrate table. An example method can include forming a vacuum sheet including a plurality of vacuum connections and a plurality of recesses configured to receive a plurality of burls disposed on a core body for supporting an object such as a wafer. Optionally, at least one burl can be surrounded, partially or wholly, by a trench. The example method can further include using the vacuum sheet to mount the core body to an electrostatic sheet including a plurality of apertures configured to receive the plurality of burls. Optionally, the example method can include using the vacuum sheet to mount the core body to the electrostatic sheet such that the plurality of recesses of the vacuum sheet line up with the plurality of burls of the core body and the plurality of apertures of the electrostatic sheet.

Abstract: Systems, apparatuses, methods, and computer program products are provided for determining a free form flatness of a substrate table. An example system can include a substrate table that includes a first substrate table surface and a grounded substrate table electrical connection configured to ground the substrate table. The system can further include a substrate that includes a semiconducting layer, a thermally-grown insulating layer, a first substrate surface disposed on the insulating layer, and a substrate electrical connection configured to transmit a voltage to the semiconducting layer. The system can further include a metrology system configured to apply a voltage to the substrate electrical connection to electrostatically clamp the substrate to the substrate table, measure a flatness of the first substrate surface, and determine a free form flatness of the first substrate table surface based on the measured flatness of the first substrate surface.

Abstract: An object holder configured to support an object, the object holder comprising: a core body comprising a plurality of burls having distal ends in a support plane for supporting the object; an electrostatic sheet between the burls, the electrostatic sheet comprising an electrode sandwiched between dielectric layers; and a circumferential barrier for reducing outflow of gas escaping from space between the object and the core body.

Abstract: Systems, apparatuses, and methods are provided for manufacturing a wafer clamp having hard burls. The method can include providing a first layer that includes a first surface. The method can further include forming a plurality of burls over the first surface of the first layer. The forming of the plurality of burls can include forming a subset of the plurality of burls to a hardness of greater than about 6.0 gigapascals (GPa).

Abstract: A substrate table for supporting a substrate includes a surface and coarse burls. Each of the coarse burls includes a burl-top surface and fine burls. The coarse burls are disposed on the surface of the substrate table. The fine burls are disposed on the burl-top surface. The fine burls contact the substrate when the substrate table supports the substrate.

Abstract: Various burl designs for holding an object in a lithographic apparatus are described. A lithographic apparatus includes an illumination system, a first support structure, a second support structure, and a projection system. The illumination system is designed to receive radiation and to direct the radiation towards a patterning device that forms patterned radiation. The first support structure is designed to support the patterning device on the first support structure. The second support structure has a plurality of burls and is designed to support the substrate on the plurality of burls. A topography of a top surface of each of the plurality of burls is not substantially flat, such that a contact area between the substrate and each of the plurality of burls is reduced. The projection system is designed to receive the patterned radiation and to direct the patterned radiation towards the substrate.

Abstract: A method for reducing sticking of an object to a surface used in a lithography process includes receiving, at a control computer, instructions for a tool configured to modify the surface and forming, in a deterministic manner based on the instructions received at the control computer, a modified surface having a furrow and a ridge, wherein the ridge reduces the sticking by reducing a contact surface area of the modified surface. Another apparatus includes a modified surface that includes furrows and ridges forming a reduced contact surface area to reduce a sticking of an object to the modified surface, the ridges having an elastic property that causes the reduced contact surface area to increase when the plurality of ridges is elastically deformed.

Abstract: Various burl designs for holding an object in a lithographic apparatus are described. A lithographic apparatus includes an illumination system, a first support structure, a second support structure, and a projection system. The illumination system is designed to receive radiation and to direct the radiation towards a patterning device that forms patterned radiation. The first support structure is designed to support the patterning device on the first support structure. The second support structure has a plurality of burls and is designed to support the substrate on the plurality of burls. A topography of a top surface of each of the plurality of burls is not substantially flat, such that a contact area between the substrate and each of the plurality of burls is reduced. The projection system is designed to receive the patterned radiation and to direct the patterned radiation towards the substrate.

Abstract: A lithographic apparatus is provided. The lithographic apparatus includes a reticle and an electrostatic clamp configured to releasably hold the reticle. The electrostatic clamp includes a first substrate having opposing first and second surfaces, a plurality of burls located on the first surface and configured to contact the reticle, a second substrate having opposing first and second surfaces. The first surface of the second substrate is coupled to the second surface of the first substrate. A plurality of cooling elements are located between the first surface of the second substrate and the second surface of the first substrate. The cooling elements are configured to cause electrons to travel from the second surface of the first substrate to the first surface of the second substrate. Each cooling element is substantially aligned with a respective burl.

Abstract: A lithographic apparatus includes a clamp (406) configured to receive an object (402). The clamp defines at least one channel (408) configured to pass a fluid at a first fluid temperature. The lithographic apparatus also includes a chuck (404) coupled to the clamp. The chuck (404) defines at least one void (464) configured to thermally insulate the chuck from the clamp.

Abstract: An electrostatic clamp (300) and a method for manufacturing the same is disclosed. The electrostatic clamp includes a first layer (302) having a first ultra-low expansion (ULE) material, a second layer (304) coupled to the first layer, having a second ULE material, and a third layer (306), coupled to the second layer, having a third ULE material. The electrostatic clamp further includes a plurality of fluid channels (316) located between the first layer and the second layer and a composite layer (308) interposed between the second layer and the third layer. The method for manufacturing the electrostatic clamp includes forming the plurality of fluid channels, disposing the composite layer on the third layer, and coupling the third layer to the second layer. The plurality of fluid channels is configured to carry a thermally conditioned fluid for temperature regulation of a clamped object.

Abstract: An electrostatic clamp (300) and a method for manufacturing the same is disclosed. The electrostatic clamp includes a first layer (302) having a first ultra-low expansion (ULE) material, a second layer (304) coupled to the first layer, having a second ULE material, and a third layer (306), coupled to the second layer, having a third ULE material. The electrostatic clamp further includes a plurality of fluid channels (316) located between the first layer and the second layer and a composite layer (308) interposed between the second layer and the third layer. The method for manufacturing the electrostatic clamp includes forming the plurality of fluid channels, disposing the composite layer on the third layer, and coupling the third layer to the second layer. The plurality of fluid channels is configured to carry a thermally conditioned fluid for temperature regulation of a clamped object.

Abstract: A lithographic projection apparatus is disclosed for use with an immersion liquid positioned between the projection system and a substrate. Several methods and mechanism are disclosed to protect components of the projection system, substrate table and a liquid confinement system. These include providing a protective coating on a final element of the projection system as well as providing one or more sacrificial bodies upstream of the components. A two component final optical element of CaF2 is also disclosed.

Abstract: A lithographic apparatus includes a clamp (406) configured to receive an object (402). The clamp defines at least one channel (408) configured to pass a fluid at a first fluid temperature. The lithographic apparatus also includes a chuck (404) coupled to the clamp. The chuck (404) defines at least one void (464) configured to thermally insulate the chuck from the clamp.