JPH11260710A - X-ray aligner and manufacture of device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray aligner which can protect an alignment mark with a simple construction and transfer an update mark. SOLUTION: An aligner, in which a mask 1 and a substrate 3 are disposed with a slight space and are exposed to an X-ray L so as to transfer a mask pattern 1p of a mask 1 onto the substrate 3, comprises a blade 10a for alignment marks 1m and 3m from the X-ray L, at the top of an alignment scope 7a. The alignment scope 7a emits an alignment light La onto the alignment marks 1m and 3m respectively disposed on the mask 1 and the substrate 3, and an alignment measurement is made. Upon exposure to an X-ray, the blade 10 shades the aligned marks 1m and 3m from the X-ray L so as to protect the mark 3 on the substrate 3 and to transfer an update mark. The protected mark 3m can be used for the alignment of the next layer; thus, it is possible to achieve an accurate alignment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray exposure apparatus used for manufacturing a semiconductor device, and more particularly to an X-ray exposure apparatus for exposing and transferring a pattern drawn on a mask onto a substrate such as a wafer by X-rays, and device manufacturing. It is about the method.

[0002]

2. Description of the Related Art In recent years, as semiconductor devices have become more highly integrated, miniaturization and higher density of semiconductor elements have been further advanced, and fine line widths are also required. When a mask pattern is transferred to a substrate such as a wafer and a semiconductor device such as a DRAM having an extremely fine line width is manufactured on the substrate, the line width becomes increasingly narrow in order to manufacture a highly integrated device.
0.25 μm in a semiconductor device of 56MDRAM,
A line width of 0.18 μm is required for a 1GDRAM semiconductor device, and the overlay accuracy of a printed pattern is, for example, 80 nm for a 256 MDRAM semiconductor device and 60 nm for a 1GDRAM semiconductor device.

As described above, an exposure apparatus for exposing and transferring a pattern drawn on a mask onto a substrate such as a wafer is demanded to have an even higher precision and a higher line width accuracy. , I-rays, KrF lasers and the like are used, but in order to avoid degradation of resolution due to diffraction, a proximity exposure apparatus using step-and-repeat using X-rays having a shorter wavelength has been proposed.

In this type of proximity exposure apparatus, a substrate such as a wafer held on a substrate stage is moved from a mask of 10 μm to 50 μm to a mask mounted on a mask stage.
This is a method in which exposure is performed in a state where the masks are brought close together with a very small interval such as m. Each exposure field angle of the substrate held on the substrate stage is sequentially moved stepwise to the exposure area facing the mask, and the mask and the substrate are aligned. Alignment is measured by an optical system and alignment is performed.
Lines are irradiated through a mask, and a mask pattern drawn on the mask is transferred onto a substrate such as a wafer by X-rays. As a method of regulating the exposure angle of view, as disclosed in Japanese Patent Application Laid-Open No. 60-74518, a light-shielding body or a masking blade (hereinafter, simply referred to as a masking blade) for regulating the exposure angle of view. ) Is provided to limit the incidence of X-rays other than the exposure angle of view.

Next, an exposure apparatus having a conventional masking blade mechanism of this type will be described with reference to FIGS. 8 and 9. FIG. The mask 1 on which the mask pattern 1p is drawn is mounted on a mask stage 2, and a substrate 3 such as a wafer is held on a substrate stage 4 and is arranged close to the mask 1 with a small interval, not shown. The X-rays L as exposure light emitted from the light emitting light source irradiate the mask 1 and the mask pattern 1 drawn on the mask 1
p is exposed and transferred onto the substrate 3. The mask 1 has a mask pattern 1 as shown in FIG.
.., 1n... are drawn along the periphery of the mask pattern together with p.
Is an alignment mark for alignment, and mark 1
n is an update mark for transferring a mark used for alignment of the next layer and subsequent layers in a later process, and is provided on the substrate 3 as an alignment mark 1m of the mask 1 as shown in FIG. A corresponding alignment mark 3m is provided on the scribe line for each exposure angle of view.

[0006] Four masking blades 5a to 5d, which are arranged above the mask stage 2 and surround the exposure area from all sides to regulate a rectangular exposure angle of view, are connected to blade stages 6a to 6d, respectively. It is provided so as to be individually movable in the direction of the arrow shown in FIG.
It is formed so that it can be set to move to the exposure angle-of-view restriction position. In addition, above the masking blades 5a to 5d,
Four alignment scopes 7a to 7d for performing alignment measurement of the mask 1 and the substrate 3 are mounted on a positioning stage (not shown).

The alignment scopes 7a to 7d irradiate alignment light La toward alignment marks 1m and 3m formed on the mask 1 and the substrate 3, respectively, and diffract light reflected from these alignment marks 1m and 3m. By detecting and measuring the alignment, and adjusting the mask stage 2, the substrate stage 4, etc.,
The mask 1 and the substrate 3 are configured to be aligned.

Prior to exposing and transferring the mask pattern 1p of the mask 1 onto the substrate 3, the alignment scope 7a
7d irradiate the alignment light La to the alignment mark 1m of the mask 1 and the alignment mark 3m of the substrate 3 while moving along each scribe line of the exposure angle of view.
The alignment measurement is performed by detecting the diffracted light or the scattered light reflected by m, 3m, and each stage is adjusted in accordance with the alignment measurement to perform the alignment between the mask 1 and the substrate 3. At this time, the masking blades 5a to
5d is retracted to a position that does not block the alignment light La. After the alignment between the mask 1 and the substrate 3 is completed, the masking blades 5a to 5d are moved by the respective blade stages 6a to 6d to set a desired rectangular exposure angle of view. X-ray L
To transfer the mask pattern 1 p of the mask 1 to the photosensitive agent applied on the substrate 3. By performing the exposure in this manner, the mark 1n for updating the mask 1 is formed on the substrate 3
And the alignment mark is updated.

In addition, a small movable blade disposed above the mask and a driving device for moving the blade in a plane parallel to the angle of view are attached to the exposure device, and the alignment mark portion is selectively formed by the blade. A method in which the mark is not exposed by exposing the mark to light is disclosed in
No. 1-172328.

[0010]

However, in the conventional apparatus as shown in FIGS. 8 and 9, regarding the alignment marks, as shown in FIG. The mark 1n of the mask 1 is transferred onto the substrate 3 and the alignment mark is updated. However, the X-rays are aligned with the alignment mark 1m of the mask 1 used for alignment measurement and the alignment mark 3m of the substrate 3 vertically. Because of the exposure, the alignment mark 3m of the substrate 3 is crushed and cannot be used anymore. Therefore, when it is desired to leave the alignment mark 3m on the substrate 3 so that it can be used for the alignment of the next layer or later in a later process, the masking blade 5 is advanced onto the alignment mark 3m where it is desired to leave the alignment mark. Exposure is performed so as to shield 3 m from exposure light. But,
In this case, there is a problem that the update mark 1n is not transferred onto the scribe line on the substrate 3.

In a conventional apparatus in which a desired alignment mark is selectively shielded from light and is not exposed by using a movable small blade, a desired mark is shielded from light by a blade and exposed. Although it is necessary to install a device for moving and positioning a small blade in a limited space, it is possible to transfer a renewal mark. It is difficult to install it in a limited space, and there is a problem that the cost increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and has been made in consideration of the above-mentioned problems. It is an object of the present invention to provide an apparatus and a device manufacturing method using the X-ray exposure apparatus.

[0013]

In order to achieve the above object, an X-ray exposure apparatus according to the present invention arranges a mask and a substrate closely at a small interval, exposes an X-ray, and writes an X-ray on the mask. In an X-ray exposure apparatus that transfers the mask pattern onto the substrate, an alignment scope for aligning the mask and the substrate is provided with a blade capable of shielding only marks that are aligned, and the blade is used during exposure by the blade. X to the mark
It is characterized in that the incidence of a line is blocked.

Further, in the X-ray exposure apparatus of the present invention, it is preferable that a masking blade for limiting the exposure angle of view is provided adjacent to the mask.

Further, a device manufacturing method of the present invention is characterized in that a device is manufactured using the X-ray exposure apparatus according to the first or second aspect.

[0016]

According to the X-ray exposure apparatus of the present invention, the alignment mark provided on the mask and the substrate is irradiated with alignment light to shield the alignment mark from the X-ray at the tip of an alignment scope for performing alignment measurement. A blade is attached, and at the time of X-ray exposure, the alignment mark, which is aligned by the alignment light, is shielded from the X-ray by the blade, thereby protecting the alignment mark on the substrate and transferring the update mark. The protected alignment mark of the substrate can be used for alignment of the next layer and thereafter, enabling accurate alignment.

[0017]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view schematically showing an X-ray exposure apparatus of the present invention, and FIG. 2 is a plan view schematically showing the X-ray exposure apparatus of the present invention with a part thereof omitted. is there.

1 and 2, a mask 1 on which a mask pattern 1p is drawn is mounted on a mask stage 2, and a substrate 3 such as a wafer is held on a substrate stage 4, and is spaced at a minute interval from the mask 1. The X-rays L as exposure light emitted from a light-emitting source (not shown) are arranged close to each other, irradiate the mask 1, and expose and transfer the mask pattern 1 p drawn on the mask 1 onto the substrate 3. It is configured. As shown in FIG. 4, a plurality of marks 1m..., 1n... Are drawn on the mask 1 along with the mask pattern 1p along the periphery of the mask pattern 1p. The mark 1n is an update mark for transferring a mark used for alignment of a subsequent layer in a subsequent process. Further, on the substrate 3, as shown in FIG. 5, alignment marks 3m... Corresponding to the alignment marks 1m of the mask 1 are provided on the scribe line for each exposure angle of view.

The masking blade that regulates the rectangular exposure angle of view is provided on the mask stage 2 so as to be as close as possible to the mask 1 in order to minimize the penumbra of exposure light generated by the edge of the masking blade. The masking blades 5a to 5d are arranged adjacent to the upper side and surround the exposure area from all sides, and these masking blades 5a to 5d are individually arranged with respect to the exposure area by arrows in FIG. Blade stages 6a to 6d provided so as to be able to advance and retreat in the direction indicated by A
It is formed so that it can be set to move to the exposure angle-of-view restriction position.

Above the masking blades 5a to 5d, four alignment scopes 7a to 7d for measuring the alignment between the mask 1 and the substrate 3 are mounted on respective positioning stages (not shown). , Alignment scopes 7a to 7d are provided so as to be movable in the direction of arrow B shown in FIG. 2 along scribe lines around each of the exposure angles of view, and alignment marks provided on mask 1 and substrate 3, respectively. The alignment light La is irradiated toward 1 m and 3 m, and the alignment light is detected by detecting the diffracted light reflected from the alignment marks 1 m and 3 m, and the mask stage 2 and the substrate stage 4 are adjusted according to the alignment measurement. By doing so, the mask 1 and the substrate 3 are aligned. The alignment scope 7
The alignment light La emitted from a to 7d is emitted obliquely at a certain angle with respect to the X-ray L in order to avoid interference with the X-ray L as exposure light.

Then, the alignment scopes 7a to 7d
As shown in FIGS. 1 and 2, alignment marks 1m, 3m
The blades 10a to 10d that block the incidence of X-rays L on the surface are fixed. Therefore, these blades 1
0a to 10d are used when the alignment scopes 7a to 7d perform alignment measurement.
a to 7d, and when the mask 1 and the substrate 3 are aligned according to the alignment measurement,
As shown in FIG. 3A, the alignment mark 1m of the mask 1 and the alignment mark 3m of the substrate 3 are vertically overlapped, and the blades 10a to 10d are also positioned above the alignment marks 1m and 3m. When the X-ray L as exposure light is exposed, the X-ray L is blocked from entering the alignment marks 1m and 3m.

Next, the X of the present invention configured as described above is used.
The operation of the line exposure apparatus will be described.

Prior to exposing and transferring the mask pattern 1p of the mask 1 onto the substrate 3, each alignment scope 7a
7d are moved along the scribe line of the exposure angle of view while irradiating alignment light La from each of the alignment scopes 7a to 7d to the alignment mark 1m of the mask 1 and the alignment mark 3m of the substrate 3.
Then, alignment measurement is performed by detecting diffracted light reflected from the alignment marks 1m and 3m. The mask 1 and the substrate 3 are aligned by adjusting the mask stage 2 and the substrate stage 4 according to the alignment measurement. At this time, if the masking blades 5a to 5d that regulate the exposure angle of view are made of a material that does not transmit the alignment light La, the masking blades 5a to 5d should be retracted to positions that do not block the alignment light La. is necessary. When a masking blade made of glass or the like that transmits alignment light is used, the alignment measurement can be performed by setting the masking blade at the exposure angle-of-view restriction position in advance.

When the alignment light La of the alignment scopes 7a to 7d is moved to the position of the alignment mark 1m of the mask 1 at the time of alignment between the mask 1 and the substrate 3, the alignment light La is fixed to each end of the alignment scopes 7a to 7d. The blades 10a to 10d are overlaid on the alignment mark 1m of the mask 1.
When the alignment between the mask 1 and the substrate 3 is completed, the alignment mark 1m of the mask 1 and the alignment mark 3m of the substrate 3 are vertically overlapped.
3m and the alignment mark 3m on the substrate 3 are overlapped with each other (see FIG. 3A). Then, after that, the masking blades 5a to 5
d is moved by each of the blade stages 6a to 6d to set a desired rectangular exposure angle of view. Next, the mask pattern 1a is irradiated with X-rays L as exposure light.
Is transferred onto the substrate 3. During the exposure of the X-ray L, the alignment mark 1m of the mask 1 and the alignment mark 3m of the substrate 3 are shielded from the X-ray L by the blade 10 of the alignment scope 7, and the X-ray L is applied to these marks 1m and 3m. Mask 1 for not reaching
The alignment mark 1m is not transferred to the substrate 3 and the alignment mark 3m on the substrate 3 can be left as it is. On the other hand, the renewal mark 1n of the mask 1 is transferred onto the scribe line of the substrate 3, and can be used for alignment of the next layer and subsequent layers in a later process.

As described above, according to the X-ray exposure apparatus of the present invention, the alignment scope can be aligned by the simple configuration in which the blade for shielding the alignment mark from irradiating X-rays is attached to the tip of the alignment scope. The existing mark can be shielded from X-rays to protect the alignment mark, and at the same time, the alignment mark can be updated. The alignment mark protected in this way can be reused for alignment of the next layer and subsequent layers in a later process, and enables accurate alignment.

Next, an embodiment of a device manufacturing method using the above-described X-ray exposure apparatus will be described.

FIG. 6 shows a micro device (a semiconductor chip such as an IC or an LSI, a liquid crystal panel, a CCD, a thin film magnetic head,
2 shows a flow of manufacturing a micromachine or the like. Step 1
In (Circuit Design), a device pattern is designed. Step 2 is a process for making a mask on the basis of the designed pattern. Step 3 (wafer manufacturing)
Then, a wafer is manufactured using a material such as silicon or glass. Step 4 (wafer process) is called a pre-process,
An actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer produced in step 4, and includes an assembly process (dicing and bonding).
It includes steps such as a packaging step (chip encapsulation). In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 7 shows a detailed flow of the wafer process. Step 11 (oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms an insulating film on the wafer surface. Step 13 (electrode formation) forms electrodes on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. Step 1
In step 5 (resist processing), a resist is applied to the wafer.
Step 16 (exposure) uses the above-described exposure apparatus to align the circuit pattern of the mask on a plurality of shot areas of the wafer and perform printing exposure. Step 17 (development) develops the exposed wafer. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

By using such a device manufacturing method, it is possible to manufacture a highly integrated device which has been conventionally difficult to manufacture at low cost.

[0031]

As described above, according to the X-ray exposure apparatus of the present invention, it is possible to transfer an update mark while protecting an alignment mark with an extremely simple structure. The alignment marks that could not be protected or updated can be performed without complicating the apparatus, so that the manufacturing cost does not increase and the decrease in throughput can be suppressed. further,
A bus with a higher degree of freedom can be manufactured, and the accuracy of the semiconductor device can be further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing an X-ray exposure apparatus of the present invention.

FIG. 2 is a plan view schematically showing the X-ray exposure apparatus of the present invention with a part thereof omitted.

FIG. 3A is an enlarged schematic diagram showing a periphery of a scribe line in a state where a mask and a substrate are aligned in an X-ray exposure apparatus of the present invention, and FIG. FIG.

FIG. 4 is a plan view of a mask.

FIG. 5 is a plan view showing a part of the substrate.

FIG. 6 is a flowchart showing a semiconductor device manufacturing process.

FIG. 7 is a flowchart showing a wafer process.

FIG. 8 is a sectional view schematically showing a conventional X-ray exposure apparatus.

FIG. 9 is a plan view schematically showing a conventional X-ray exposure apparatus with a part thereof omitted.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mask 1p Mask pattern 1m Alignment mark 1n Mark for updating 2 Mask stage 3 Substrate (wafer) 3m Alignment mark 4 Substrate stage 5 (5a-5d) Masking blade 6 (6a-6d) Blade stage 7 (7a-7d) Alignment Scope 10 (10a to 10d) Blade L X-ray (exposure light) La Alignment light

Claims (3)

[Claims] 1. An X-ray exposure apparatus for arranging a mask and a substrate close to each other with a small space therebetween and exposing the mask pattern drawn on the mask by X-ray exposure onto the substrate. X is characterized in that an alignment scope for aligning the substrate is provided with a blade capable of shielding only the aligned mark from light, and the blade blocks X-rays from entering the mark during exposure. Line exposure equipment. 2. The X-ray exposure apparatus according to claim 1, wherein a masking blade for limiting an exposure angle of view is provided adjacent to the mask. 3. A device manufacturing method, comprising manufacturing a device using the X-ray exposure apparatus according to claim 1.