Nikon Corporation

Toshio Ueta

Michael B Binnard

Bausan Yuan

Pai-Hsueh Yang

Ting-Chien Teng

Wen-Hou Ma

W Thomas Novak

A stage assembly () that moves a work piece () about a first axis and along a first axis includes a first stage (), a second stage () that retains the work piece (), a second mover assembly (), a measurement system, and an initialization system (A). The second mover assembly () moves the second stage () relative to the first stage () about the first axis. The measurement system () monitors the position of the second stage () about the first axis when the second stage () is positioned within a working range about the first axis. The initialization system (A) facilitates movement of the second stage () about the first axis when the second stage () is rotated about the first axis outside the working range. The second mover assembly () can include a mover () and a dampener () that reduces the transmission of vibration from the first stage () to the second stage (). In addition, the stage assembly () can include a control system () that directs power to the mover () to position the second stage () and to compensate for vibration of the first stage ().

Stage assembly with measurement system initialization, vibration compensation, low transmissibility, and lightweight fine stage

A wafer stage countermass assembly generally includes a base supporting one or more stages and first and second countermasses. The first and second stages move in one or more degrees of freedom. The countermasses move in at least one degree of freedom and, under ideal conditions, move to counter the movement of the stages in operation and thus preserve the systems center of gravity to avoid unwanted body motion. However, under actual conditions the countermasses may under travel or over travel their ideal trajectory. To more closely track the ideal trajectory, a controller actuates trim motors to apply small forces to the countermasses to push them towards a reference position in the Y direction. A second embodiment also takes into account the X position the stage(s) to cancel torque.

Stage counter mass system

A wafer stage assembly, wafer table servo control system, and method for operating the same, are provided for use in combination with a projection lens assembly in a semiconductor wafer manufacturing process. The wafer stage assembly includes a wafer stage base supporting a wafer stage to position the semiconductor wafer, a wafer table connected to the wafer stage to support the wafer, a plurality of sensors, and an actuator. The sensors include a first sensor to determine a position of an exposure point on the wafer relative to the projection lens assembly, and a second sensor to determine a position of a focal point of the projection lens assembly relative to the exposure point. To increase focusing properties of the projection lens assembly, in response to the determined positions of the exposure point and the focal point, the actuator moves the wafer table so that the exposure point substantially coincides with the focal point. The wafer table servo control system is provided to operate the wafer stage assembly. The servo control system includes a first sensor controller to generate a first position signal of an exposure point on the wafer table relative to a projection lens assembly, and a second sensor controller to generate a second position signal of a focal point of the projection lens assembly relative to the exposure point. The servo control system also includes a wafer table controller to determine and generate a correction force corresponding to the first and second position signals. The correction force is then exerted onto the wafer table to bring the exposure point to substantially coincide with the focal point.

Wafer stage assembly, servo control system, and method for operating the same

With respect to exposure apparatus, apparatus and methods are disclosed for compensating for lateral shift of a leveling table caused by a tilt (&thgr;) of the leveling table. One embodiment includes a wafer-stage-position loop servo, a leveling-table tilt-position loop servo, and a first feed-forward loop from the leveling-table tilt-position loop servo to the wafer-stage-position loop servo. The first feed-forward loop converts a torque-control signal for the leveling table to a linear-acceleration-control signal for the wafer stage. Thus, the wafer stage moves laterally to compensate for lateral shift of the leveling table. If the exposure apparatus includes a reticle stage controlled by a reticle-stage-position loop servo, then the subject apparatus can include (in addition to or in place of the first feed-forward loop) a second feed-forward loop from the leveling-table tilt-position loop servo to the reticle-stage-position loop servo. The second feed-forward loop converts a positional signal for the leveling table to a position-control signal for the reticle stage, to cause the reticle stage to undergo lateral compensatory motion. The methods and apparatus provide a faster and more accurate compensation for lateral shifts of the leveling table.

Devices and methods for compensating for tilting of a leveling table in a microlithography apparatus

A method and apparatus for implementing an active vibration isolation system (AVIS) is provided. The AVIS includes a pneumatic control system and an electronic control system. The pneumatic control system supports a mass sensitive to vibration and isolates the mass from high frequency external disturbances. The electronic control system isolates the mass from low frequency external disturbances. The pneumatic control system includes a compliance chamber filled with a fluid to pneumatically support the mass, pressure sensor to measure the pressure level in the compliance chamber, and pneumatic actuator to control the pressure level to minimize the effects of pressure variation in the compliance chamber. The electronic control system includes at least one motion sensor to measure the actual position of the mass as the mass moves due to vibration, at least one feedback system to generate a corresponding signal, an electronic controller to generate signal(s) representing the calculated electronic force needed to compensate for the vibration, and an electronic actuator to generate the electric force to isolate the mass from the external disturbances. The pneumatic and electronic control systems work together to provide high frequency response and eliminate heat dissipation from the electronic control system.

Method and apparatus for operating a vibration isolation system having electronic and pneumatic control systems

A wafer stage device and control system are provided to stabilize a wafer stage and a wafer table in a wafer manufacturing process. The wafer table supports the semiconductor wafer, while the wafer stage is accelerated in response to a wafer manufacturing control system to position the wafer table. The wafer stage device includes a set of flexures connecting the wafer table to the wafer stage. The flexures are positioned in a plane which is substantially in alignment with an upper surface of the wafer. The flexure's configuration causes a rotational error, such as pitching or rolling, of the wafer table as the wafer stage moves. The wafer stage device further includes a plurality of actuators to control the rotational error by exerting a stabilizing torque to the wafer table. The control system determines the stabilizing torque necessary to correct the pitching or rolling error of the wafer table.

Growing community of inventors

Kumagaya, Japan

Toshio Ueta