JPH0273111A - Stage positioning instrumentation system - Google Patents

Abstract

PURPOSE:To shorten a mirror to miniaturize the mirror by performing measurement in the position, where position instrumentation cannot be performed by laser measurement, with a position measuring means using no mirrors. CONSTITUTION:A laser interferometer 7 for Y-axis position measurement is used to measure the position in the Y-axis direction of a moving base 4, and the position in the X-axis direction of the moving base 4 is measured by laser measurement of a laser interferometer 6 for X-axid position measurement and position data read on a scale 3. That is, laser measurement of the interferometer 6 is not performed but position measurement of the scale 3 is performed when an X-axis stage 2 is moved to the position shown in a figure (3). When the stage 2 is in the position shown in a figure (2), instrumentation is performed by laser measurement. A mirror 5 is shortened by a part corresponding to a length (a) in the figure (3), and the mirror is miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a stage positioning and measuring system suitable for use in semiconductor manufacturing equipment and the like.

[Prior Art] Conventionally, in positioning this type of stage, only one type of length measurement method has been selected from various length measurement methods such as a laser length measurement device, a scale, or a feed amount count using an encoder connected to a ball screw for feeding the stage. was hiring.

In cases where particularly high precision is required, in many cases only position measurement using a laser length measuring device is currently used as the device with the highest precision and widest measuring range.

[Problem to be solved by the invention] However, when using a laser length measuring device for positioning, if there are two or more axes, the mirror for laser length measurement must be large enough to cover the entire movement range of the stage. As the movement range becomes wider, the mirror becomes larger, which causes problems as described below.

(1) Increasing the size of the mirror causes higher costs, delivery delays, and lower precision in mirror manufacturing.

(2) The rigidity of the stage decreases due to the increased weight of the mirror.

The purpose of the present invention is to solve the problems in the conventional example described above.
To provide a stage positioning measurement system that can perform laser length measurement using a small mirror even when the range 8a of the stage is wide, thereby reducing costs, shortening delivery time, and improving accuracy.

[Means and effects for solving the problem] In order to achieve the above object, in the stage positioning measurement system according to the present invention, the stage positioning device does not necessarily require precise positioning accuracy by laser length measurement over the entire positioning range. In consideration of this, the size of the mirror is kept to the minimum necessary limit, and the stage positioning system is switched to a stage positioning system using a length measurement method that does not use a mirror outside the laser positioning range.

That is, the present invention includes two systems: a first position measuring means using a laser length measuring device and a mirror (a small one is sufficient), and a second position measuring means that does not use a mirror. If the stage is outside the positioning range of the laser length measuring device, the stage positioning system is switched to a stage positioning system using the second position measuring means, thereby making it possible to downsize the mirror.

[Example code] Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a plan view of the X and Y stages in a stage positioning and measuring system according to an embodiment of the present invention. 2 is a plan view of the stage shown in FIG. 1 when the xIIiIII stage is placed at one end, and FIG. 3 is a plan view of the stage shown in FIG. 1 when the X glaze stage is placed at the opposite end from that shown in FIG. In these figures, 1 is a Y-axis stage, 2 is an X-axis stage, 3 is a scale that can read numerical values electrically or optically, 4 is a moving table, 5 is a mirror for laser length measurement, and 6 is a mirror for laser length measurement. 7 is a laser interferometer for measuring the X-axis position, 9 is a laser interferometer for Y-axis position measurement, and 9 is used to switch between the measurement system using the scale 3 and the measurement system using the interferometer 6, or from the measurement system. This is a control CPU that processes the information and drives and controls the X and Y stages.

In this embodiment, an interferometer 7 is used to measure the position of the movable table 4 in the Y-axis direction. The position of the movable table 4 in the X-axis direction is measured by laser length measurement using an interferometer 6 and position data reading using a scale 3.

That is, when the X-axis stage 2 moves to the position shown in FIG. 3, the laser length measurement by the interferometer 6 is not performed.
Position measurement using scale 3 is performed. On the other hand, in the state shown in FIG. 2, measurement is performed by laser length measurement. According to this embodiment, the mirror 5 can be shortened in a portion corresponding to the distance 11ia in FIG. 3, and the mirror can be made smaller.

FIG. 4 is a plan view showing a second embodiment of the invention.

In this second embodiment, the scale 3 in the embodiment of FIG. 1 is replaced with a drive mechanism 8 that has the function of counting the amount of movement using an encoder or the like and confirming the current stage position. .

Note that switching between the two measuring means can be done by storing the switching timing in the CPU as position information so that the switching occurs at a predetermined position of one of the measuring means, or by switching when one of the measuring means detects a predetermined signal. There are methods etc.

[Effects of the Invention] As explained above, according to the present invention, at positions where position measurement cannot be performed by laser length measurement, the position measurement means that does not use a mirror is used to measure the position, so the mirror can be shortened. It is possible to downsize the mirror. By miniaturizing the mirror, the effects described below can be enhanced.

(1) The mirror can be manufactured easily, reducing costs, shortening delivery time, and improving accuracy.

(2) Since the weight of the mirror is reduced, the rigidity of the stage is relatively increased, the natural frequency is increased, and the control of the bow becomes easier.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the X and Y stages in a stage positioning and measurement system according to an embodiment of the present invention. FIG. 2 is a plan view of the stage shown in FIG. 1 when the X-axis stage is placed at one end. FIG. 3 is a plan view of the X-axis stage when it is placed at the end opposite to that shown in FIG. 2, and FIG. 4 is a plan view of the XY stage of the second embodiment of the present invention. Structure, 9: Control CPU.

Claims (2)

[Claims] (1) In order to position and measure the stage, a first position measuring means uses a laser length measuring device and a corresponding mirror, and a second position measuring means does not use a mirror other than the laser length measuring device. A stage positioning measurement system comprising two systems, and further comprising means for switching to a stage positioning system using a second position measurement means when the stage is outside the positioning range of the first position measurement means. . (2) The stage positioning measurement system according to claim 1, wherein the second position measurement means uses an optical scale, a magnetic scale, or pulse conversion using an encoder.