JPH02110953A - High-accuracy positioning - Google Patents

Abstract

PURPOSE:To reduce an adverse effect, such as a dimensional deviation due to an external vibration and a residual vibration and the like, by a method wherein, after a slight movement stage is positioned at a prescribed position of a second member by a coarse movement stage, the slight movement stage is moved to a supporting member and at the same time, is fixed and a first member is positioned at a desired position of the second member by the slight movement stage. CONSTITUTION:A slight movement stage 18, which holds a first member 5 on it to perform a precise positioning of the member 5 in directions X and Y, a coarse movement stage 10, which mounts the stage 18 on it to perform a rough positioning of the stage 18 in the directions X and Y, and a supporting member 7, which opposes to the member 5 to hold a second member 8, are provided and the member 5 is positioned at a desired position of the member 8 by the stages 10 and 18. In such a high-accuracy positioning method, after the stage 18 is positioned at a prescribed region of the member 8 by the stage 10, the stage 18 is separated from the stage 10 by a moving means (a moving member) 17, is moved to the member 7 and at the same time, is fixed and the member 5 is positioned at a desired position of the member 8 by the stage 18.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a method for positioning a second member with high precision with respect to a first member, with the aim of reducing adverse effects such as dimensional deviation due to external vibrations and residual vibrations. a fine movement stage that holds the member No. 1 and performs precise positioning in the XY force directions; a coarse movement stage that is equipped with a fine movement stage and roughly positions the fine movement stage in the XY force directions;
A high-precision positioning method comprising: a support member that holds a second member opposite to the first member; the first member is positioned at a desired position on the second member using a coarse movement stage and a fine movement stage; After positioning the fine movement stage in a predetermined area of the second member by the coarse movement stage, the fine movement stage is separated from the coarse movement stage by the moving means and moved to the support member and fixed, The first member is configured to be positioned at a desired position of the second member using a fine movement stage.

[Industrial application field]

The present invention relates to a method for positioning a second member with high precision with respect to a first member.

2. Description of the Related Art As LSIs become smaller and more highly integrated, there is an increasing demand for higher precision in techniques for exposing and transferring circuit patterns on a mask onto a wafer.

The present invention is mainly applied to a stepper that exposes and transfers a circuit pattern on a mask onto a wafer, and positions the mask and wafer with high precision.

[Conventional technology]

The perspective view in FIG. 5 and the side view in FIG.
This figure shows a vertical stepper that exposes and transfers a circuit pattern on a mask onto a wafer using a light source (referred to as R) as a light source.

The vertical stepper will be explained below.

In the conventional ultraviolet exposure stepper, the mask and wafer are placed horizontally and a light source is placed above for exposure, whereas SOR light is emitted horizontally and has a very short wavelength, so it is exposed using a mirror. Therefore, both the mask and the wafer are placed vertically and exposed.

As shown in the figure, there is an X-axis guide 2 in front of the upright wafer stage head l, and above the X-axis guide 2 there is a movable X-axis guide 3, using a linear ball screw etc. not shown in the figure. These two guides constitute a coarse movement stage 4 that roughly positions the wafer, which will be described later.

Above the coarse movement stage 4, as shown in FIG. 6, there is a freely movable fine movement stage 6 which holds the wafer 5 and performs precise positioning in the XY force directions using an electro-mechanical conversion element such as a piezoelectric element. installed.

Therefore, the wafer 5 is moved between the coarse movement stage 4 and the fine movement stage 6.
can move freely in the X and Y force directions, and sequentially positions the areas of the wafer 5 to be exposed on the mask 8 held on the mask table 7 by a step-and-repeat operation,
Exposure can be performed using SOR light 9 irradiated through a mask 8 .

[Problem to be solved by the invention]

In the configuration of the stepper as described above, the mask table 7 has a large mass, and the coarse movement stage 4 has a castle-like movement mechanism that can move in the XY force directions, so it has a large mass, and the natural vibration of both The number becomes low, and it vibrates at a low frequency due to external vibrations and stage drive reaction force.

Therefore, the mask and wafer vibrate significantly at relatively low frequencies, making it extremely difficult to position and hold them with high precision, and it is difficult to accurately expose and transfer the pattern of the mask onto the wafer. There were several problems.

An object of the present invention is to reduce the adverse effects such as dimensional deviation due to external vibrations and residual vibrations, and to perform highly accurate positioning of opposing members.

[Means to solve the problem]

In order to achieve the above object, in the present invention, as shown in FIG. The fine movement stage 18 is separated from the coarse movement stage 10 by the moving means 17, moved to the support member 7, and fixed, and the fine movement stage 18 moves the first member (for example, a wafer) 5 to the second member (mask). ) 8 at the desired position.

[Effect]

The fine movement stage is roughly positioned in a predetermined area of the second member held by the support member by the coarse movement stage, and then the fine movement stage is separated from the coarse movement stage and moved to the support member by the moving means. do.

Then, the fine movement stage is fixed to the support member by suction.

After that, the first member held by the fine movement stage is precisely moved to the desired position of the second member by a fine movement stage that has a high natural frequency due to its small mass and no low frequency vibrations caused by external vibrations. to be located.

At this time, the low frequency vibration of the support member vibrates together with the fine movement stage because it is fixed to the member, and no relative positional displacement occurs.

〔Example〕

1 to 4 show an embodiment of the present invention.

Identical parts are designated by the same reference numerals throughout the figures.

As shown in the side view of FIG. 1, the present invention uses a fine movement stage that holds a first member (hereinafter referred to as wafer) 5, such as a wafer, for precise positioning in the X and Y directions, as in the prior art. 18, a coarse movement stage IO on which the fine movement stage 18 is mounted and roughly positions the fine movement stage 18 in the X and Y directions, and a second member such as a mask (hereinafter referred to as mask) 8 facing the wafer 5. After the fine movement stage 18 is positioned in a predetermined area of the mask 8 by the coarse movement stage 10, the fine movement stage 18 is coarsely moved by the moving means 17. The wafer 5 is separated from the stage 10 and moved to the support member 7 and fixed, and the fine movement stage 18 moves the wafer 5 to the mask 8.
The object is positioned at a desired position with high precision.

That is, the fine movement stage 18 is equipped with a wafer chuck 11 that vacuum-chucks the wafer 5, as shown in the front view of FIG. The outer edge is provided with a suction portion 12 for vacuum suction to the support member 7 of the mask 8.

13 is a vacuum suction groove provided around the suction part 12,
It is exhausted via pipe 14.

Further, 15 is a wafer suction groove.

FIG. 3 shows that the above-mentioned fine movement stage system is connected to the support member 7 of the mask.
FIG.

As shown in the figure, the mask 8 is held by a fine movement Zθ stage 16 that can be adjusted in the Z direction (back and forth direction) and the θ direction (rotational direction), the fine movement Zθ stage 16 is fixed to the support member 7, and the mask 8 is It is possible to move in each direction.

An exposure procedure according to an embodiment of the present invention will be illustrated with reference to the side view of FIG.

First, as shown in FIG. 1A, the coarse movement stage IO is moved in steps to position the wafer 5 in a predetermined area of the mask 8.

At this time, the fine movement stage 18 is moved by a moving means 17 that is provided on the coarse movement stage 1o and moves the fine movement stage 18 in the Z direction.
is maintained depending on.

Next, as shown in FIG.
comes into contact with.

As shown in the same figure (C1), after the first idle stage 18 is vacuum-adsorbed to the support member 7 by the suction unit 12, the moving means 17 releases the holding of the violent stage IB.

After precise positioning of the wafer 5 using the fine movement stage 18, exposure is performed using, for example, SOR light 9.

In this manner, the circuit pattern of the mask 8 is exposed and transferred onto the wafer 5 by the stepper.

As described above, the detailed description of the present invention has been given regarding a stepper that exposes and transfers a circuit pattern on a mask onto a wafer, but the present invention is not limited to steppers, and there is a possibility that positional deviation may occur due to external vibrations. It goes without saying that the present invention is applicable to all devices that precisely position two opposing members of the invention and ensure their relative positions with high precision.

〔Effect of the invention〕

Since the fine movement stage can limit its movable range to a small size, it can have a highly rigid and lightweight structure.

Therefore, its natural frequency is high and large vibrations at low frequencies due to external vibrations no longer exist.

In addition, the low-frequency vibrations of the support member vibrate together because the fine movement stage is fixed to the member, and the relative positional relationship remains unchanged, making it possible to position the two opposing members with high precision. It has great economic and industrial effects.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the mechanism that realizes the high-precision positioning method of the present invention, Figure 2 (al is a front view of the fine movement stage used in the high-precision positioning method of the present invention, and Figure 2 (b) is the same figure) fa), FIG. 3 is a side view showing the state in which the violently moving stage of FIG. 2 is attracted to the mask support member, and FIG. An explanatory diagram showing the procedure, FIG. 5 is a perspective view of a vertical stepper to which the present invention is mainly applied, and FIG. 6 is a side view of FIG. 5. In the figure, 1 is a wafer stage, 2 is a Y Axis guide, 3 is X-axis guide, 4.10 is coarse movement stage, 5 is first member (wafer), 6.18 is fine movement stage, 7 is support member, 8 is second member (mask), 9 is the SOR light, 11 is the wafer chuck, 12 is the suction part, 13 is the vacuum suction groove, 14 is the tube,
15 is a wafer suction groove, 16 is a fine movement Zθ stage, and 17 is a moving means. +・Gaga, @ If) Soko f1 Hisa [k Mugi γ Shio j Hoya ji tosuru floor KL Thinome Katakuchi V / Diagram 3 mouth

Claims (1)

[Claims] A fine movement stage (18) that holds the first member (5) and performs precise positioning in the XY directions, and a fine movement stage (18) on which the fine movement stage (18) is mounted.
18) in the X and Y directions, and a support member (7) that holds the second member (8) facing the first member (5), The coarse movement stage (10) and the fine movement stage (18)
the first member (5) to the second member (8)
In a high-precision positioning method for positioning the fine movement stage (10) at a desired position, the coarse movement stage (10)
After positioning the fine movement stage (18) in a predetermined area of the second member (8), the fine movement stage (
18) is separated from the coarse movement stage (10) and moved and fixed to the support member (7), and the first member (5) is moved to the second member by the fine movement stage (18).
A highly accurate positioning method characterized in that the member (8) is positioned at a desired position.