JPH065691A - Semiconductor light exposure device - Google Patents

Abstract

PURPOSE:To provide a wafer or mask light exposure device provided with an aligning stage where a wafer or a mask is set and which prevents defocus or local defocus caused by dusts at exposing a wafer or a mask to light. CONSTITUTION:A semiconductor light exposure device is equipped with an alignment stage composed of a transfer rail 4, a transfer arm 5 movable in directions of x and y along the transfer rail 4 and provided with a rotatable suction piece 6 which sucks a light exposure object 12, a stage 7 provided with a vacuum chuck 8 which sucks the light exposure object 12 transferred by the transfer arm 5, three or more laser ray irradiating means 9 which irradiate laser rays toward the front from the rear of the stage 7, and a laser ray detecting means 10 provided corresponding to the laser ray irradiating means 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer or mask exposure apparatus, and more particularly to an alignment stage for setting a wafer or mask.

In recent years, most of electronic devices have a pattern rule of submicron because the degree of integration is increasing. To make such an electronic device,
It is necessary to prevent defocus (defocus) from occurring during exposure in the photolithography process.

It requires an alignment stage that can correct the distortion of the wafer or mask to flatten it during exposure.

[0004]

2. Description of the Related Art FIG. 3A shows a plan view of a stage of an exposure apparatus for setting a wafer or a mask.
A side view is shown in (b). In the figure, 21 is a stage, 22 is a vacuum chuck having a vacuum suction means (not shown), 23 is a positioning pin provided at a position corresponding to the orientation flat of the wafer or mask, and 24 is It is a positioning pin provided at a position corresponding to the circumference.

The wafer or mask 26 is placed on the vacuum chuck 22 so that the orientation flat corresponds to the two positioning pins 23 and one point on the circumference corresponds to the positioning pins 24, and the positioning hammer 25 is used. Then press the wafer or mask 26 toward the center to
Alignment is completed by contacting all 24 with the edge of the wafer or mask.

Prior to this alignment, as shown in FIG. 4, the wafer or mask 26 is pre-aligned on a pre-alignment stage 27 having the same structure, and the transfer arm 28 carries out a vacuum chuck 22 on the stage 21. It is transported to the top and set. Wafer or mask 26 to pre-alignment stage 27 to stage
The mechanical displacement of the transfer arm 28 (50-
100 μm) deteriorates the alignment accuracy of the wafer or mask set on the vacuum chuck 22 of the stage 21, so that the alignment is performed again on the stage 21 as described above.

After the alignment is completed, the wafer or the mask 26 is sucked by the vacuum suction means (not shown) of the vacuum chuck 22, the positioning hammer 25 is returned to the original position, and the exposure is started.

[0008]

The wafer or mask is not at all flat and there are distortions. For distorted wafers or masks, positioning pins 23 and 24 and positioning hammer
When aligned with 25, the wafer or mask 26 contacts at the height B position, rather than at the height A position of the locating pins 23 or 24, as shown in FIG. Vacuum chuck the wafer or mask 26 in this state.
When it is adsorbed at 22, the wafer or mask 26 in this area is vacuum chucked due to the friction with the positioning pins 23 or 24.
22 does not come into close contact with the positioning pin 23 or 24
A strain of about 5 to 6 μm remains in the 40 mm range, and defocus occurs in this region during exposure, making it impossible to form a resist pattern.

Further, when the wafer or mask 26 is pushed by the positioning hammer 25, the wafer or mask 26 and the vacuum chuck 22 rub against each other, so that the dust adhered to the wafer or mask 26 adheres to the vacuum chuck 22. Local defocus occurs in this part when the next wafer or mask is set.

An object of the present invention is to eliminate these drawbacks. When aligning a wafer or a mask on the stage of an exposure apparatus, the distortion of the wafer or the mask is corrected and flattened, and the data during the exposure is corrected. It is an object of the present invention to provide a semiconductor exposure apparatus having an alignment stage that prevents focus from occurring and local defocus due to dust.

[0011]

The above-mentioned object is to carry rails (4) and x, y along the rails (4) for carrying.
A transfer arm (5) that moves in the direction and has a rotatable suction portion (6) that sucks the exposed object (12) at the tip, and the exposed object (1) transferred by the transfer arm (5).
A stage (7) having a vacuum chuck (8) for adsorbing 2), at least three light emitting means (9) for emitting light from the back surface to the front surface of the stage (7), and the light emitting means (9). Light detecting means (10) provided corresponding to
And a delivery pin (11) for delivering the object to be exposed (12) transported by the transport arm (5) onto the stage (7). It

[0012]

A method of aligning a wafer or a mask will be described with reference to the principle explanatory diagram shown in FIG. Transport arm 5
The wafer or the mask is adsorbed to the adsorption part 6 of, and is moved on the transfer rail 4 to be transferred onto the stage 7. Laser is irradiated from the laser irradiation means 9, the laser detection means 10 detects this, and the transfer arm 5 is moved in the x and y directions so that the edge portion of the wafer or mask coincides with the laser irradiation position. After the suction unit 6 is rotated and alignment is performed, a wafer or a mask is set on the vacuum chuck 8 via the transfer pins 11.

As described above, since the alignment is performed in a non-contact state by using the laser beam instead of the contact between the wafer or the mask and the positioning pin as in the conventional case, the wafer or the mask is sucked by the vacuum chuck 8. At this time, since there is no part of the wafer or mask that causes friction that hinders the attraction, the entire surface of the wafer or mask is attracted to the vacuum chuck 8 and becomes flat, and the distortion existing in the wafer or mask is corrected. Focus is reduced.

Since the wafer or mask is aligned while being separated from the vacuum chuck 8, the wafer or mask and the vacuum chuck 8 are aligned at the time of alignment.
Are no longer rubbed against each other, and the dust adhering to the wafer or the mask is not adhering to the vacuum chuck 8, so that local defocusing does not occur.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An alignment stage according to the gist of an exposure apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a block diagram of the wafer or mask alignment apparatus. In the figure, 1 is a pre-alignment stage, 2 is a positioning pin, and 3 is a positioning hammer.

Reference numeral 4 denotes a carrier rail, and 5 has a suction portion 6 for sucking a wafer or a mask at a tip portion thereof. This is a transfer arm, and the transfer arm 5 has a moving function in x and y directions and a rotating function in the suction portion 6 at the tip.

Reference numeral 7 is a stage of the exposure apparatus, 8 is a vacuum chuck having a vacuum suction means (not shown) provided on the stage, and 9 is a laser beam emitted from the back surface to the front surface of the stage. The laser irradiating means is provided at two locations on the orientation flat portion and one location on the circumferential portion corresponding to the shape of the wafer or mask to be exposed. Reference numeral 10 is a laser detection means for detecting the laser light emitted from the laser irradiation means 9 to detect the edge portion of the wafer or mask. Reference numeral 11 is a transfer pin used to place the wafer or mask transferred by the transfer arm 5 on the vacuum chuck 8.

First, the wafer or mask 12 is placed on the pre-alignment stage 1, and the positioning hammer 3 pushes the wafer or mask 12 toward the center to bring it into contact with the three positioning pins 2, thereby completing the pre-alignment. The wafer or mask 12 for which pre-alignment has been completed is pushed up by a transfer pin (not shown), the transfer arm 5 is moved below the wafer or mask 12, and the wafer or mask 12 is sucked by the suction portion 6 at the tip.

The transfer arm 5 is moved along the rail 4 onto the stage 7 and the laser irradiation means 9 irradiates a laser, which is detected by the laser detection means 10 so that the edge portion of the wafer or the mask 12 is at the laser irradiation position. When the transfer arm 5 is moved in the x and y directions so as to coincide with
Adjust by rotating. When the adjustment is completed, the delivery pin
The wafer 11 or mask 12 is lifted until it slightly contacts the lower surface of the wafer or mask 12, and the suction of the suction portion 6 is released to support the wafer or mask 12 with the transfer pins 11. Then, the transfer arm 5 is moved to the outside of the wafer or mask 12, and then the transfer pin 11 is lowered to set the wafer or mask 12 on the vacuum chuck 8.

It should be noted that until the wafer or mask 12 is set on the vacuum chuck 8, the laser detecting means 10 continues to check whether or not the alignment is misaligned.
After confirming that no displacement has occurred, the wafer or mask 12 is suctioned by the vacuum chuck 8 and exposure is started.

As an example, the alignment accuracy is 50 μm.
A laser sensor was used in order to make the thickness m or less, but an optical sensor is used if the alignment accuracy is 100 μm to 500 μm. For example, a photo sensor or the like can be used.

[0023]

As described above, in the semiconductor exposure apparatus according to the present invention, the alignment of the wafer or the mask is performed by using a laser in a non-contact system.
When the wafer or the mask is sucked by the vacuum chuck after the completion of the alignment, the entire surface of the wafer or the mask is sucked and becomes flat, so that defocusing is reduced. Further, since the wafer or mask and the vacuum chuck do not rub against each other, dust is prevented from adhering to the vacuum chuck and local defocusing is prevented, so that a good resist pattern is formed and the yield of electronic devices is improved. If it is improved by 10 to 20%, the reliability is remarkably improved.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a configuration diagram of an alignment stage of the exposure apparatus according to the present invention.

FIG. 3 is a configuration diagram of an alignment stage of an exposure apparatus according to a conventional technique.

FIG. 4 is a diagram showing a relationship between a pre-alignment stage and a stage.

FIG. 5 is an explanatory diagram of defocus occurrence.

[Explanation of symbols]

 1 Pre-Alignment Stage 2 Positioning Pin 3 Positioning Hammer 4 Transfer Rail 5 Transfer Arm 6 Adsorption Part 7 Stage 8 Vacuum Chuck 9 Laser Irradiation Means (Light Emitting Means) 10 Laser Detection Means (Light Detection Means) 11 Delivery Pins 12 Wafer or Mask ( Exposed object)

Claims (1)

[Claims] 1. A transfer rail (4) and a rotatable suction unit (6) which moves along the transfer rail (4) in the x and y directions and which sucks an object to be exposed (12) at its tip.
And a stage (7) having a transfer arm (5) having a vacuum chuck (8) for adsorbing the object to be exposed (12) transferred by the transfer arm (5), and a back surface of the stage (7) At least three light emitting means (9) for irradiating the surface with light, and light detecting means (1) provided corresponding to the light emitting means (9).
0) and an alignment stage including a transfer pin (11) for transferring the object to be exposed (12) transferred by the transfer arm (5) onto the stage (7). apparatus.