Abstract:
A support table for a lithographic apparatus, a method of loading a substrate, a lithographic apparatus and a method for manufacturing a device using a lithographic apparatus. In one arrangement, a support table is configured to support a substrate. The support table has a base surface. The base surface faces a surface of the substrate when the substrate is supported by the support table. One or more gas cushion members are provided above the base surface. Each of the gas cushion members includes a recess. The recess is shaped and configured such that a lowering of the substrate into a position on the support table at which the substrate is supported by the support table causes a localised build-up of pressure within the recess. The localized build-up of pressure provides a localised gas cushioning effect during the lowering of the substrate.
Abstract:
An improved squeeze bearing apparatus exhibits torsional stiffness or rotational restraint since its rod-like bearing member (22) and its sleeve-like bearing member (28) comprise non-circular perimeters (26,32).
Abstract:
A piezoelectric ultrasonic suspension in gas for creating a contactless bearing support of a precision instrument and specifically an electromagnetic motor. A gas micro-film of elevated pressure is formed between the adjoining surfaces of a spherical saddle and a spherical trunnion. The spherical trunnion is spaced apart from the spherical surface of a saddle by a gas micro-film when the piezoresonator is excited.
Abstract:
An ultrastiff precision sonic bearing assembly and method thereof for controlling an effective coefficient of friction between two elements in slidable contact configured along an interface under a force sufficient to maintain contact and having static friction therebetween, by inducing a repetitive motion in one of the elements parallel to the interface thereby altering the effective coefficient of friction therebetween. The bearing assembly also provides for additional and independent electronic control over the average thickness thereof and senses the force thereon to allow the bearing assembly stiffness to be altered.
Abstract:
A dynamic pressure bearing is provided with a moving side bearing member and a fixed side bearing member so as to support a rotor for rotation by generating a fluid dynamic pressure between the moving side bearing member and the fixed side bearing member. The dynamic pressure bearing includes a high-frequency exciting device for applying a high-frequency vibration to the fixed side bearing member at the time of at least one of start-up and shutdown of the rotor. In this way, both bearing members are kept almost free from contact with each other and a frictional resistance at start-up and/or shutdown is minimized.
Abstract:
A hydraulic thrust bearing having bearing members with horizontally aligned, spaced bearing surfaces and a liquid completely filling the space between the surfaces. One member is oscillated normal to the bearing surfaces to generate a positive load supporting force in the bearing.