A method for processing a semiconductor wafer is provided. The method includes transferring the semiconductor wafer above a wafer placement device having a plate to align an edge of the semiconductor wafer with a first buffer member positioned in a peripheral region of the plate and to align a center of the semiconductor wafer with a second buffer member positioned in a central region of the plate. Each of the first buffer member and the second buffer member has a stiffness that is less than that of the plate. The method further includes lowering down the semiconductor wafer to place the semiconductor wafer over the plate.

A positioning apparatus includes a guide, a movable member capable of moving in a first direction while being guided by the guide, and a driver configured to drive the movable member in the first direction. The driver includes a feed screw extending in the first direction, a nut configured to threadably engage with the feed screw and move in the first direction along with a rotation of the feed screw, and a connecting device configured to connect the nut and the movable member. The connecting device includes a hollow rod with one end connected to the movable member and the other end connected to the nut, and the feed screw is inserted into a hollow portion of the rod.

An object holder configured to support an object, the object holder including: a core body comprising a plurality of burls having distal ends in a support plane for supporting the object; and an electrostatic sheet between the burls, the electrostatic sheet comprising an electrode sandwiched between dielectric layers, wherein the electrostatic sheet is bonded to the core body by a bonding material having a thickness of at least 100 nm.

A position measurement system including a first interferometer and a second interferometer arranged to determine a distance of the object in a first direction when the object is in a first measurement area by emitting beams onto a target surface of the object. The position measurement system further has a third interferometer and a fourth interferometer arranged to determine a distance of the object in the first direction when the object is in a second measurement area by emitting beams onto the target surface of the object. An arrangement of relative positions in a second direction of beams spots impinging on the target surface from the beams emitted by the first and second interferometers is different from an arrangement of relative positions in the second direction of beams spots impinging on the target surface from the beams emitted by the third and fourth interferometers.

A support table for a lithographic apparatus, the support table having a support section and a conditioning system, wherein the support section, the conditioning system, or both, is configured such that heat transfer to or from a substrate supported on the support table, resulting from the operation of the conditioning system, is greater in a region of the substrate adjacent an edge of the substrate than it is in a region of the substrate that is at the center of the substrate.

An apparatus for use in a metrology process or a lithographic process, the apparatus including: an object support module adapted to hold an object; and a first gas shower arranged on a first side of the object support module and adapted to emit a gas with a first velocity in a first gas direction which is a horizontal direction to cause a net gas flow in the apparatus to be a substantially horizontal gas flow in the first gas direction at least above the object support module.

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.

In a method of manufacturing a photo mask for lithography, circuit pattern data are acquired. A pattern density, which is a total pattern area per predetermined area, is calculated from the circuit pattern data. Dummy pattern data for areas having pattern density less than a threshold density are generated. Mask drawing data is generated from the circuit pattern data and the dummy pattern data. By using an electron beam from an electron beam lithography apparatus, patterns are drawn according to the mask drawing data on a resist layer formed on a mask blank substrate. The drawn resist layer is developed using a developing solution. Dummy patterns included in the dummy pattern data are not printed as a photo mask pattern when the resist layer is exposed with the electron beam and is developed.

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.

A positioning system and method for positioning a semiconductor device are disclosed. In an embodiment, a positioning system for positioning a semiconductor device includes a long-stroke stage configured to be movable with respect to a supporting structure within a plane and a short-stroke stage attached to the long-stroke stage and configured to carry a semiconductor device and to be rotatable within the plane. The long-stroke stage acts as a balance mass between the short-stroke stage and the supporting structure.