Abstract:
A method, system, and computer program product for non-real-time trajectory planning and real-time trajectory execution. A trajectory planning process receives data generated by high-level control software. This data defines positions and scan velocities, where multiple axis motion must be precisely synchronized. The trajectory planning process creates sequences of constant acceleration intervals that allow critical motions to be executed at maximum throughput. The output of a trajectory planning process is known as a profile. A profile executor, using the profile output by the trajectory planner process, generates continuous, synchronized, filtered, multi-axis position and acceleration commands (i.e., execution data) that drive control servos. Time intervals generated by the trajectory planner are quantized to be integer multiples of a real time clock period. The trajectory planner outputs have infinite jerk, but are smoothed by filters in the profile executor to both limit jerk and minimize servo-tracking errors. The trajectory planner allows time for the profile executor filters, but does not restrict fine tuning of the shape of these filters, provided that the width of the tuned filter does not exceed the allowed time.
Abstract:
A lithography system and method are used to increase throughput using multiple reticles to pattern multiple substrates that are positioned with respect to one another according to a predetermined sequence. For example, during a first exposure period a first reticle patterns a first set of substrates, during a second exposure period a second reticle patterns a second set of substrates, during a third exposure period the first reticle patterns a third set of substrates, etc., until all desired substrates are patterned. It is to be appreciate that after the first and second reticles are complete, third and fourth reticles can pattern the first, second, third, etc. sets of substrates.
Abstract:
This invention is directed to electro-magnetic alignment apparatus, which is particularly adapted, among many other possible uses, for use in aligning the wafers in a microlithography system, said apparatus including in combination at least three magnet assemblies which are mounted in space relationship one with respect to the others, at least three coil assemblies mounted to pass through the high flux region of the magnet assemblies respectively, the width of the coil assemblies being substantially less than the width of the high flux regions respectively, a controller for controlling the flow of current through the coil assemblies respectively, a structural assembly for connecting the coil assemblies which is movable with respect to the magnet assemblies, the coil assemblies being wound with respect to each other so that by controlling the supply of current to the coils the structure assembly can be moved selectively in three degrees of freedom.
Abstract:
A system and method include an object supported on a moveable support, an optical system that transmits radiation onto the object, a support having an aperture therethrough, a sensor system coupled to the support, and a control system coupled to the sensor system and the moveable support. The sensor system is arranged with respect to the aperture to measure a surface of the object and send measurement signals to the control system, such that the control system generates control signals received and used by the moveable support to ensure that the surface of the object receiving light transmitted by the optical system through the aperture is in a focus plane of the optical system.
Abstract:
Provided are a method and system for measuring a distance to an object. The system includes an air gauge configured to sense a distance to a surface of the object and a sensor configured to measure at least one from the group including (i) a relative position of the air gauge and (ii) a relative position of the surface of the object. Outputs of the air gauge and the sensor are combined to produce a combined air gauge reading.
Abstract:
An apparatus for maintaining an optical gap between a pellicle and a reticle in a photolithography system includes a frame defining first and second opposing surfaces, a reticle mated to the first opposing surface using magnetic coupling and a pellicle mated to the second opposing surface using magnetic coupling.
Abstract:
An apparatus for stabilizing a scanning system during lithographic processing comprises a baseframe, a reaction mass, and a pair of flexures connecting the reaction mass to the baseframe. The apparatus also comprises a second reaction mass and a second pair of flexures, placed in parallel to the first to form a split reaction mass system. The apparatus is configured such that, upon acceleration of a stage movably coupled to the reaction masses, a resulting load is split substantially evenly between the first and second reaction masses. Also upon acceleration of the stage, the first reaction mass rotates in the opposite direction of the second reaction mass, resulting in a net moment reaction on the baseframe of approximately zero.
Abstract:
In a reflective lithographic projection apparatus, shifts in the image of a pattern of a mask in the scanning direction caused by variations in the position of the pattern surface of the mask along the optical axis are corrected by shifting of the relative position of the mask and/or the substrate in the scanning direction. Correction of the image rotation error may also be accomplished by rotation of the relative positions of the mask and/or the substrate about the optical axis. Variations in the position of the pattern surface of the mask along the optical axis may be determined by interferometers upon installation of the mask to the lithographic projection apparatus. The variations may be mapped and stored to provide control of the lithographic projection apparatus.
Abstract:
A trajectory planning process receives data generated by high-level control software. This data defines positions and scan velocities. The trajectory planning process creates sequences of constant acceleration intervals that allow critical motions to be executed at maximum throughput. The trajectory planning process outputs a profile. A profile executor, using the profile output by the trajectory planner process, generates continuous synchronized, filtered, multi-axis position and acceleration commands that drive control servos. Time intervals generated by the trajectory planner are quantized to be integer multiples of a real time clock period. The trajectory planner outputs have infinite jerk, but are smoothed by filters in the profile executor to both limit jerk and minimize servo-tracking errors. The trajectory planner allows time for the profile executor filters, but does not restrict fine tuning of the shape of these filters, provided that the width of the tuned filter does not exceed the allowed time.
Abstract:
An apparatus and method for precisely detecting very small distances between a measurement probe and a surface, and more particularly to a proximity sensor using a constant gas flow and sensing a mass flow rate within a pneumatic bridge to detect very small distances. Within the apparatus the use of a flow restrictor and/or snubber made of porous material and/or a mass flow rate controller enables detection of very small distances in the nanometer to sub-nanometer range. A further embodiment wherein a measurement channel of a proximity sensor is connected to multiple measurement branches.