JPH0224012B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an exposure apparatus for semiconductor production, and in particular,
The present invention relates to a stage moving device for highly accurately positioning and moving a stage on which a sample such as a semiconductor wafer is placed.

(Prior Art) In recent years, with the miniaturization of semiconductor integrated circuits, a high precision exposure apparatus is required. What is essential to this exposure apparatus is a highly accurate movement and positioning device.

Here, an example of a conventional X-ray exposure apparatus will be outlined with reference to FIG.

A stage 13 is movably disposed in the exposure apparatus housing 12, and a wafer 14 is placed on the stage 13 and locked by an air lock means 121. When positioning the wafer 14 and the exposure mask 15, alignment (positioning) between the mask 15 and the wafer 14 is performed using alignment marks provided on the mask 15 and the wafer 14. First, the microscope 16 moves from the position shown by the broken line to the position shown by the solid line. Here, the mask 1 is exposed to light from the light source 17.
5 and the wafer 14 are displayed on a monitor 18 via a microscope 16. Further, this alignment mark signal is input to an alignment mark detection device 19, and an alignment error is detected. Then, the stage 13 is moved by the scanner 20 based on this error. When the above alignment error falls within the allowable value, the microscope 16 moves from the position shown by the solid line to the position shown by the broken line, and the SOR light 21 moves to the position shown by the broken line.
The wafer 14 is exposed to light.

(Problem to be Solved by the Invention) By the way, in the case of a conventional exposure apparatus, each time when aligning a mask and a wafer, the microscope, that is, the positioning detection device SOR moves so as to block the optical path, and the alignment is interrupted. When the alignment is completed, the positioning detection device is moved to substantially open the SOR light path, and then exposure is performed with the SOR light. Since the positioning detection device must be moved each time alignment is performed, there is a problem in that the throughput (production amount per unit time) is low.

Furthermore, there is a problem in that detection of alignment between the mask and the wafer is affected by errors caused by movement of the positioning detection device.

An object of the present invention is to provide a stage moving mechanism with high throughput and high positioning accuracy.

(Means for Solving the Problems) According to the present invention, an exposure mask is movably supported on a linear axis guide and movably supported in a direction perpendicular to the linear axis guide, and an exposure mask is arranged respectively. the first and second frames;
first and second stages on which the wafer is placed, which are supported movably in the linear axis guide direction and the perpendicular direction, respectively, within the frame, and predetermined first and second standby stages. 1st in each position
and first and second alignment means provided corresponding to the second stage and for positioning the wafer and the exposure mask; the first frame body and the first stage are integrated; It is characterized by having a moving means for moving the frame body and the second stage together to the exposure position, and positioning at the first and second standby positions and movement to the exposure position are performed alternately. A stage moving device is obtained.

(Function) In the stage moving device of the present invention, at the first standby position, the wafer placed on the first stage and the mask placed on the first frame are positioned by the first alignment means. During the exposure, the wafer placed on the second stage and the mask on the second frame are positioned by the second alignment means, moved to the exposure position, and exposed. In this manner, in the present invention, the wafer and mask are positioned alternately at the first and second standby positions and moved to the exposure position.

(Example) The present invention will be explained below with reference to Examples.

First, referring to FIG. 1, a rectangular support frame 1 has a plurality of linear guide rods 1a (first
(In the figure, there are 4) attached. On the other hand, near the left end of the support frame 1, a plurality of guide rods 1c are attached to the support frame 1 through sliders 1d at predetermined intervals so as to be perpendicular to the linear guide rod 1a. A first frame 2 on which an exposure mask is disposed, as described later, is supported on the above-mentioned linear guide rod 1a so as to be movable in the longitudinal direction (hereinafter referred to as the X-axis direction). Further, the frame body 2 is movable along the guide rod 1c, that is, along the Y axis shown in FIG.

A plurality of guide rods 2 are arranged in the frame 2 in the X-axis direction.
A are attached to the frame 2 at predetermined intervals via sliders 2b, and a plurality of guide rods 2c are attached to the frame 2 at predetermined intervals via sliders 2d perpendicular to the guide rods 2a. As will be described later, a first stage 3 on which a semiconductor wafer is placed is supported on the guide rod 2a so as to be movable in the X-axis direction. Further, this first stage 3 is movable in the Y-axis direction along the guide rod 2c.

Similarly, near the right end of the support frame, a second frame 4 is supported by a linear guide rod 1a so as to be movable in the X-axis direction, and this second frame 4 is movable along the guide rod 1e in the Y It is movable in the axial direction. Note that the guide rod 1e is attached to the support frame 1 via a slider 1f. slider 4
A second stage 5 is supported movably in the X-axis direction on a guide rod 4a attached to the frame 4 via b, and this second stage 5 is movable in the Y-axis direction along a guide rod 4c. be. Note that the guide rod 4b is connected to the second rod via the slider 4d.
It is attached to the frame 4 of. The heights of the first frame body 2 and the second frame body 4 are different, and the heights of the first frame body 2 and the second frame body 4 are different from each other.
This prevents axial drive from interfering with each other.

Referring also to FIG. 2 (in FIG. 2, only the first frame 2 and first stage 3 on the left side are shown in FIG. 1), Wafer chuck mechanism 6 via piezo element 6a
The wafer chuck mechanism 6 is rotatable on the first stage 3. and,
A wafer 7 is held by a chuck mechanism 6. On the other hand, a mask stage 8 is connected to the frame 2, and a mask 9 is arranged and supported.

By the way, as shown in FIG. 1, the first frame 2 and the first stage 3 are located near the left end of the support frame 1 (hereinafter referred to as the first standby position) and correspond to the first stage 3. A first alignment mechanism is provided. In addition, the second frame 4 and the second stage 5 are in the vicinity of the right end of the frame 1 (hereinafter referred to as the second stage 5).
A second alignment mechanism is provided corresponding to the second stage 5 (referred to as a standby position) (note that the first and second alignment mechanisms are not shown in FIG. 1).

The alignment mechanism includes a leveling mechanism and a positioning mechanism. As shown in FIG. 2, the leveling mechanism includes a laser oscillator 10a and a lens system 10.
b, beam splitter 10c, mirror 10d~
10g and a photodetector 10h, and the mirrors 10d to 10g are supported by the mask stage 8.

The laser light from the laser oscillator 10a passes through a lens system 10b, a beam splitter 10c, a reticle (not shown), and mirrors 10d and 10e to form a focal point on the wafer 7, and the light reflected from the wafer 7 is focused on the mirror 10g. It is reflected, forms a focal point again on the wafer 7, and passes through the beam splitter 1.
It is input to the photodetector 10h via 0c. Since the above-mentioned reticle is formed on the support material that supports the mirror 10e, when the distance between the reticle and the wafer 7 moves away from a predetermined position (focus position), that is, the distance between the mask 9 and the wafer 7 becomes a predetermined distance. When moving away from the position, the output from the photodetector 10h becomes weaker. Therefore, the chuck mechanism 6 is adjusted by the piezo element 6a so that the output from the photodetector 10h is maximized, and the parallelism and distance between the wafer 7 and the mask 9 are set at predetermined positions.

On the other hand, as shown in FIG. 3, the positioning mechanism includes a laser oscillator 11a, an f-theta lens 11b, a prism 11c, beam splitters 11d and 11e, mirrors 11f to 11i, lenses 11j and 11k, and photodetectors 11l and 11m. etc.

The laser beam from the laser oscillator 11a passes through the f-theta lens 11b and is split into two paths by the prism 11c. One of the lights passes through a beam splitter 11d, mirrors 11f and 11g, passes through a reticle (not shown) formed on the mask 9, and hits a mark (diffraction grating) on the wafer. The diffracted light generated by the wafer mark follows the opposite path to the above case and passes through the beam splitter 11d to the photodetector 11.
input into l.

Similarly, other light passes through the beam splitter 11e, mirrors 11h and 11i, passes through the reticle, and hits the wafer mark. The diffracted light generated by the wafer mark follows the opposite path, passes through the beam splitter 11e, and is input to the photodetector 11m.

Based on the amount of light detected by the photodetectors 11l and 11m, the amount of light blocked by the reticle can be known, and the positional relationship between the reticle, that is, the mark on the mask 9 and the wafer 7 can be known. Therefore, the photodetector 11
The stage 5 is finely adjusted in the X-axis direction or the Y-axis direction so that the amount of detected light at 1 and 11 m is maximized.

Note that, as described above, the mask on the frame 4 and the wafer on the stage 5 are also positioned by the second alignment mechanism.

Referring also to FIG. 4, the second frame 4 and the second stage 5 are moved as one body from the second standby position to the exposure position by a moving means (not shown),
The wafer is exposed to SOR light. When exposure is being performed on the second stage 5, alignment is performed on the first frame 2 (mask 9) and the first stage 3 as described above, and the first
The frame body 2 and the first stage 3 are waiting in a state where alignment has been completed. When the exposure on the second stage 5 is completed, the second frame 4 and the second stage 5 return to the second standby position, and the first frame 2 and the first stage 3 return to the first standby position. The camera moves from the position to the exposure position, and exposure starts. At this time, alignment of the second frame 4 and the second stage 5 is performed. In this way, the first
Alignment on the second stage, movement to the exposure position, and exposure are performed alternately.

(Effects of the Invention) As described above, the present invention includes a first frame on which a mask is placed, and a first stage on which a wafer is placed corresponding to the first frame. In addition, a second frame body on which a mask is placed, and a second stage on which a wafer is placed corresponding to this frame body, and a second stage on which a wafer is placed, which corresponds to the first and second stages. Each of them is equipped with a first and second alignment mechanism that aligns the wafer and the mask, and alignment at the first and second stages and exposure at the exposure position are performed alternately, so the alignment mechanism There is no alignment error between the wafer and the mask due to the positioning accuracy of There is an advantage.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the main parts of the stage moving mechanism used in the present invention, FIG. 2 is a diagram for explaining the operation of the leveling mechanism of the alignment mechanism used in the present invention, and FIG. 3 is a perspective view showing the main parts of the stage moving mechanism used in the present invention. FIG. 4 is a diagram for explaining the operation of the positioning mechanism of the alignment mechanism used, FIG. 4 is a diagram for explaining the alignment operation and exposure operation, and FIG. 5 is a diagram showing a conventional exposure apparatus. DESCRIPTION OF SYMBOLS 1... Support frame body, 2... First frame body, 3... First stage, 4... Second frame body, 5... Second stage, 6... Wafer chuck mechanism, 7... Wafer, 8...mask stage, 9...mask.

Claims (1)

[Claims] 1. First and second frames that are movably supported on a linear axis guide and movably supported in a direction perpendicular to the linear axis guide, and in which exposure masks are disposed, respectively; first and second stages on which the wafer is placed, which are supported movably in the linear axis guide direction and the perpendicular direction, respectively, within the frame of No. 2, and predetermined first and second stages.
first and second alignment means, which are provided corresponding to the first and second stages, respectively, at standby positions for positioning the wafer and the exposure mask; and the first frame and the second stage. a moving means for integrally moving the second frame body and the second stage to the exposure position; A stage moving device characterized by alternately moving to an exposure position.