摘要:
An encoder emits modulated light from a light source section and lets a first light and a second light separated from the modulated light interfere with each other in a moving grating. In the encoder, the light emitted from the light source section is electrically modulated, and the first light and the second light have different light path lengths.
摘要:
A mirror block on which moving gratings are arranged is fixed to the lower surface of a stage. Fixed gratings are placed on the upper surface of a stage platform that is opposed to the lower surface of the stage. A Y encoder that measures Y positional information of the stage is configured including the moving gratings and the fixed gratings. Similarly, an X encoder that measures X positional information of the stage is configured including the moving gratings and the fixed grating.
摘要:
The present invention performs calculations on photoelectric conversion signals (Ia, Ib, Ic, Id) supplied from a light receiving device and calculates two signals (IA, IB) as a result. Furthermore, the signal (IAB) is generated based on the signals (IA, IB), and the signal (IAB) is output from the encoder. As shown in equation, the term in the signal (IAB) that depends on the time t is 4d−sin(ωt). Moreover, as shown in equations (5) and (6), the term that depends on the time t in the signals (IA, IB) is 2d−sin(ωt); consequently, the signal (IAB) varies with respect to the signals (IA, IB) on a scale substantially tantamount to doubling the degree of modulation. Accordingly, if the position of the movable scale is detected based on the signal (IAB), then that position can be detected with good accuracy on a scale tantamount to doubling the degree of modulation.
摘要:
When an incident light is obliquely incident on an index scale, the optical path length of light A becomes longer than the optical path length of light B and an optical path length difference occurs, which causes a phase difference in both of the diffracted lights incident on a photodetection element. According to the phase difference, intensity of a photoelectric detection signal output from the photodetection element changes. That is, due to a periodic change in the incident angle of the incident light, the phase difference between light A and light B is modulated, and the interference signal becomes greatly modulated.
摘要:
A moving grating is arranged on a side of a wafer stage, a light source irradiates a light to the moving grating, diffracted lights generated from the moving grating are interfered by fixed scales and an index scale of which positional relation with the light source is fixed, and a detection instrument detects the interfered light. In this case, since the moving grating is arranged on a side of the wafer stage, upsizing of the entire wafer stage can be suppressed. Further, since interference occurs between a plurality of diffracted lights (e.g., the ±1st-order diffracted light) passing extremely close optical paths, influence caused by a fluctuation of ambient atmosphere becomes less in comparison to conventional interferometers, and thus, a high-precision measurement of positional information of the movable body is possible.
摘要:
A light via first and second index scales is split by a beam splitter, and one of the split lights is received by a first light-receiving element via a movable scale and also the other of the split lights is received by a second light-receiving element via a reference scale, and therefore by computing positional information of the movable scale using an output of the first light-receiving element (a first output) and an output of the second light-receiving element (a second output), movement information of the movable scale can be measured with high precision without being affected by drift of the modulation center (the oscillation center) of the beam.
摘要:
Methods and apparatus for supporting the weight of a first stage of a stage apparatus using magnets are disclosed. According to one aspect of the present invention, and apparatus includes a first structure, a second structure, and an anti-gravity device. The anti-gravity device has a first magnet and a piston arrangement that includes a second magnet. The first magnet is coupled to the first structure, and the piston arrangement is movably interfaced with the second structure through an air bearing. The first magnet and the piston arrangement cooperate to support the first structure over the second structure relative to a vertical axis.
摘要:
Embodiments of the present invention are directed to a control system and method for controlling the trajectory and alignment of one or more stages by incorporating a grouping method in the control methodology. In one embodiment, a method of controlling movement of one or more stages of a precision assembly to process a substrate having a plurality of process regions comprises dividing the substrate into blocks according to one or more preset criteria, each block of the substrate including one or more process regions; generating learning data for one or more representative process regions for each block of the substrate; and using the generated learning data of the one or more representative process regions of each block to control movement of the one or more stages to process the block of one or more process regions of the substrate.
摘要:
A scanning type exposure apparatus includes a mask stage position-measuring unite a substrate stage position-measuring unit, an arithmetic processing unit, and a control unit. The arithmetic processing unit multiplies results of measurement (WX, WY, W.theta.) by the substrate position-measuring unit by a conversion vector including components containing a magnification of a projection optical system and an angle of rotation between a mask and a substrate to determine a target vector quantity (RX*, RY*, R.theta.*) of a mask stage. An error vector is determined by subtracting, from the target vector quantity, results of measurement (RX, RY, R.theta.) by the mask stage position-measuring unit. The controller controls the mask stage so that the error vector becomes zero. The exposure apparatus includes correcting sections for correcting time lags in measurement by the respective position-measuring units. The arithmetic processing unit uses corrected positional information. The mask stage can accurately follow a substrate stage.
摘要:
A projection optical apparatus comprises a projection optical system for projecting the image of an object onto a substrate, data collecting means for obtaining data regarding a factor which causes a variation in the optical characteristic of the projection optical system, adjusting means for adjusting the relation between the substrate and the image of the object relative to the variation in the optical characteristic of the projection optical system, means for determining the amount of adjustment by the adjusting means in accordance with a model formula using a predetermined parameter on the basis of the data obtained by the data collecting means, means for independently measuring the variation in the optical characteristic of the projection optical system, and means for correcting the parameter of the model formula on the basis of the result measured by the measuring means.