JPH10209033A - Apparatus for position stage and aligner using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid pollution in an exposure chamber atmosphere with impurity gases leaking from a drive of a positioning stage. SOLUTION: An exposure chamber 1 is controlled to hold a low pressure atmosphere of a high-purity He gas fed by a feed line 14 with an exhaust line 13. A wafer holder 4 is moved along a Y-axis by a drive having an air cylinder 12 as a coarse actuator and linear motor 11 as a fine actuator. The same gas as the He gas fed from the feed line 14 is used for a driving medium fed to the air cylinder 12 not to a vary the purity of the atmosphere in the chamber 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a positioning stage device driven in an atmosphere of a special gas such as helium gas and an exposure apparatus using the same.

[0002]

2. Description of the Related Art A positioning stage apparatus for positioning a wafer or the like with respect to an exposure light or a mask in an exposure apparatus or the like for manufacturing semiconductors is capable of moving each exposure field angle of a wafer at a high speed to an exposure light irradiation area. Two types of actuators are provided: a coarse movement actuator for moving, and a fine movement actuator for highly accurately aligning (aligning) the stepped exposure angle of view with a mask or the like.

In general, an air cylinder which can generate a large thrust is used as a coarse actuator, and a linear motor which can control very precisely and has good response is used as a fine actuator. It is.

FIG. 5 shows a positioning stage apparatus E _{0 according} to a conventional example, which comprises an X stage 102 which is reciprocally movable in the X-axis direction on a surface plate 101, and a Y-axis direction which is movable on the X stage 102. Stage 1 that can reciprocate freely
03, and a drive unit for moving the Y stage 103 in the Y-axis direction, which has a wafer holding plate 104 disposed on the Y stage 103, and a pair of driving units disposed in the Y-axis direction along the X stage 102. Linear motor 111 and Y stage 103
Is constituted by an air cylinder 112 disposed on the back side.

[0005] Each linear motor 111 is connected to the X stage 10.
Stator 111a fixed to one end of Y stage 1 and Y stage 1
03 and the mover 111b.
b has a through hole through which the stator 111a passes. When a driving current is supplied to the stator 111a, the movable element 111
b is generated in the Y-axis direction, and the Y stage 10
3 is moved in the Y-axis direction.

The air cylinder 112 is mounted on the X stage 10
2 and a pressurizing chamber 112b integral with the Y stage 103. The piston rod 112a penetrates an opening 112c provided at one end of the pressurizing chamber 112b. It protrudes into. A piston rod 11 is supplied from a pressurized air supply source (not shown).
When pressurized air is supplied into the pressurized chamber 112b through the internal pipe 112d of 2a, the Y stage 103 moves in the + Y-axis direction (upward in the figure), and conversely, the pressurized air in the pressurized chamber 112b is After being discharged through the pipe 112d, the Y stage 103 moves in the −Y axis direction (downward in the figure).

The gap between the opening 112c of the pressurizing chamber 112b and the piston rod 112a is formed by pressurized air flowing out of the pressurizing chamber 112b through the gap without using a sealing material such as an O-ring. A so-called non-contact gas seal that maintains non-contact is configured.

This is because, if a sealing material such as an O-ring is used, positioning accuracy and controllability may be impaired due to heat generation and stick-slip caused by contact with the piston rod 112a.

The driving section for driving the X stage 102 in the X-axis direction also has a pair of linear motors 113 disposed at both ends of the X stage 102 and an air cylinder 114 disposed on the back side of the X stage 102. These are the linear motor 111 of the Y stage 103, the air cylinder 11
2 is configured in the same manner.

The positions of the Y stage 103 in the X-axis direction and the Y-axis direction are measured with high precision by a laser length measuring device (not shown) using a laser beam applied to the square mirror 115. Is fed back to the drive unit.

The Y stage 103 and the X stage 10
A gap of several microns is maintained between the upper guides 2 by an air pad 105 or the like, and is kept in a non-contact state. A space between the X stage 102 and the surface plate 101 is also kept in a non-contact state by the same air pad.

Air cylinders 112 and 113 of each drive unit
Generates a large thrust for step-moving the wafer held on the wafer holding plate 104 to the exposure light irradiation area. The reason why the air cylinder is used as the coarse motion actuator is that heat generation at the time of thrust generation is small, and there is no possibility of generating thermal strain on the wafer holding plate, the wafer, and the like.

The entire positioning stage device E ₀ is
It is arranged in an exposure chamber (not shown). In the case of an exposure apparatus or the like that uses X-rays such as charged particle storage ring radiation (SR-X-rays) as exposure light, the atmosphere in the exposure chamber, which is a sealed chamber, is controlled to a reduced pressure atmosphere of a special gas such as helium gas. . This prevents the attenuation of X-rays that are significantly attenuated by the atmosphere or the like, and promotes the heat radiation of a wafer or the like heated by the X-rays during exposure.

[0014]

However, according to the above prior art, the purity of helium gas and the like in the exposure chamber is reduced due to the impurity gas such as air leaking from the air pad of the positioning stage device and the air cylinder of each drive unit. There is an unsolved problem that the intensity of X-rays or the like during exposure cannot be kept constant due to changes in pressure or pressure, resulting in significant exposure unevenness or the like.

In order to prevent such a trouble during exposure, the exposure chamber is continuously evacuated, for example, to 99.99.
%, A technique has been developed to dilute the contamination by the impure gas to prevent a decrease in purity by continuing to supply helium gas of extremely high purity. However, running cost is reduced by consuming a large amount of expensive helium gas. , Which results in higher prices for semiconductor products and the like.

The present invention has been made in view of the above-mentioned unresolved problems of the prior art, and is intended to prevent the atmosphere in a sealed chamber such as an exposure chamber from being contaminated by gas leaking from a driving unit or the like. It is an object of the present invention to provide a positioning stage device which can be avoided and an exposure apparatus using the same.

[0017]

In order to achieve the above-mentioned object, a positioning stage apparatus according to the present invention comprises a moving stage movable along guide means provided in a sealed chamber; And a control unit for controlling the sealed chamber to an atmosphere of a predetermined gas, wherein the drive unit includes a fluid pressure cylinder using a fluid of the same component as the predetermined gas as a drive medium. It is characterized by having.

[0018] The hydraulic cylinder may have an opening sealed by a contactless gas seal.

It is preferable that a leak gas exhaust means is provided for discharging a part of the leak gas leaking from the opening of the fluid pressure cylinder to the outside of the sealed chamber directly from the opening.

It is preferable to provide a magnetic means for maintaining a non-contact between the moving stage and the guide means by magnetic repulsion.

[0021]

If the drive unit for moving the moving stage holding a substrate such as a wafer in a sealed chamber is provided with a hydraulic cylinder using a fluid such as air as a drive medium, leakage (leakage) occurs from the hydraulic cylinder. The air and the like change the purity and the like of the atmosphere in the sealed chamber, which contributes to uneven exposure and the like. Therefore, by using a fluid having the same component as the atmosphere in the sealed chamber as a drive medium for the fluid pressure cylinder, it is possible to prevent a decrease in the purity of the atmosphere and to prevent uneven exposure due to the purity.

As compared with the case where high-purity helium gas is always flown into the sealed chamber to dilute contamination caused by air leaking from the drive unit of the positioning stage device, consumption of expensive helium gas is reduced. Therefore, there is no possibility that the running cost of the exposure apparatus will increase.

If a leak gas exhaust means is provided for discharging a part of the leak gas leaking from the opening of the fluid pressure cylinder directly to the outside of the sealing chamber from the opening, the sealing speed can be adjusted by adjusting the exhaust speed of the leak gas. The purity of the atmosphere in the chamber can be controlled.

If a magnetic means for maintaining the moving stage and the guide means in a non-contact state by a magnetic repulsion is provided, as in the case of using a gas bearing such as an air pad, an impurity gas leaking from the bearing portion is prevented. Therefore, it is possible to prevent the purity of the atmosphere in the sealed chamber from being reduced.

As described above, by effectively avoiding troubles due to impurity gas leaking from the drive unit and the bearing unit of the moving stage, fluctuations in the purity and pressure of the atmosphere in the sealed chamber during exposure can be prevented, and exposure can be prevented. Uniform exposure without unevenness can be performed. Further, since there is no need to constantly supply high-purity helium gas, a large amount of expensive helium gas is not consumed. That is, it is possible to realize an exposure apparatus that can perform exposure with extremely high precision at a low running cost.

[0026]

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

FIG. 1 shows a positioning stage apparatus E _{1 according} to a first embodiment, which is arranged along a pair of guide members 2 as guide means provided in an exposure chamber 1 which is a sealed chamber. A driving unit that has a Y stage 3 that is a movable stage that is reciprocally movable in the axial direction and a wafer holding plate 4 that is disposed on the Y stage 3, and that drives the Y stage 3 in the Y axis direction includes a guide member 2. And a pair of linear motors 11 arranged along the line, and an air cylinder 12 which is a fluid pressure cylinder arranged on the back side of the Y stage 3.

The linear motor 11 has a stator 11a fixed to the guide member 2 and a mover 11b integral with the Y stage 3. The mover 11b has a through hole through which the stator 11a passes. When a driving current is supplied to the stator 11a, a thrust for driving the mover 11b in the Y-axis direction is generated, and the Y stage 3 is moved in the Y-axis direction.

The air cylinder 12 has a piston rod 12a erected on the bottom wall of the exposure chamber 1 and a pressurizing chamber 12b integral with the Y stage 3.
Protrudes into the pressurizing chamber 12b through an opening 12c which is an opening provided at one end of the pressurizing chamber 12b. When a high-purity helium gas, which is a driving medium (fluid), is supplied from a helium gas supply source (not shown) into the pressurizing chamber 12b via the internal pipe 12d of the piston rod 12a, the Y stage 3 moves in the + Y axis direction (upward in the figure). ), And conversely, when the helium gas in the pressurizing chamber 12b is discharged through the internal pipe 12d, the Y stage 3 moves in the −Y axis direction (downward in the figure).
Go to

The gap between the opening 12c of the pressurizing chamber 12b and the piston rod 12a is formed by helium gas flowing out of the pressurizing chamber 12b through the gap without using a sealing material such as an O-ring. It forms a so-called non-contact gas seal that keeps in contact.

X between the Y stage 3 and the bottom wall of the exposure chamber 1
When a stage is provided, the drive unit similarly has a pair of linear motors disposed at both ends of the X stage and an air cylinder disposed on the back side of the X stage. The configuration is the same as the linear motor 11 and the air cylinder 12 of the Y stage 3.

The position of the Y stage 3 in the X-axis direction and the Y-axis direction is measured with high precision by a laser length measuring device (not shown) using a laser beam applied to the square mirror 3a.
This is fed back to a driving unit such as the Y stage 3.

Instead of providing an air pad between the Y stage 3 and the guide member 2, a magnetic material is used for each guide member 2, and the magnets 5 provided at both ends of the Y stage 3 face each other. . The guide member 2 and the magnet 5 maintain a gap of several microns by magnetic repulsion,
And the magnetic means for keeping the Y stage 3 in non-contact.

The air cylinder 12 generates a large thrust for stepwise moving each exposure angle of view of the wafer as the substrate held on the wafer holding plate 4 to the irradiation area of the X-ray as the exposure light. The reason why the air cylinder is used as the coarse motion actuator is that heat generation at the time of thrust generation is small, and there is no possibility of generating thermal strain on the wafer holding plate, the wafer, and the like.

At the start of each exposure cycle, the wafer held on the wafer holding plate 4 is step-moved by the air cylinder as described above, and the exposure angle of view is positioned in the X-ray irradiation area. 11 is driven to perform alignment with respect to a mask or the like. When exposure is completed by irradiating the wafer with X-rays from a light source (not shown), the air cylinder 12 is driven again to move the next exposure angle of view to the X-ray irradiation area, and the above steps are repeated.

During each exposure cycle, the exposure chamber 1 is controlled to a reduced pressure atmosphere of helium gas to prevent X-ray attenuation. Since the helium gas has a characteristic that X-ray attenuation is smaller than that of the atmosphere, the inside of the exposure chamber 1 is evacuated to a high vacuum by an exhaust line 13 serving as an exhaust unit, and then the exhaust line 1 is exhausted.
A high-purity helium gas, which is an air supply gas, is supplied from an air supply line 14 which is an air supply means which constitutes an atmosphere control means together with 3 to control the atmosphere to a reduced pressure atmosphere of, for example, about 200 Torr.

The pressure of the helium gas is the atmosphere in the exposure chamber 1, an air cylinder 1 of the positioning stage device E ₁
2. Leakage from the second pressure chamber 12b through the opening 12c (leak)
The pressure in the exposure chamber 1 is monitored by a pressure sensor 15 which is a pressure detecting means because the pressure gradually rises due to the helium gas which is a leaking gas. Valve 1
The opening of 3a and 14a is adjusted.

According to the present embodiment, since the gas leaking from the air cylinder constituting the drive unit of the stage is high-purity helium gas, the purity of the helium gas in the exposure chamber may be reduced as in the conventional example. Absent. Further, since the guide member and the Y stage are kept out of contact with each other by the magnetic means, there is no possibility that impurity gas leaks from the guide portion of the stage as in the case of using an air pad or the like.

Therefore, it is not necessary to always supply an expensive helium gas to the exposure chamber in order to maintain the purity of the helium gas in the exposure chamber. As a result, the helium gas consumption is significantly reduced, and an exposure apparatus with low running cost and high transfer accuracy can be realized.

Although the present embodiment is a positioning stage device having only a Y stage, a guide member for the Y stage is provided on the X stage, and a two-stage structure having the same drive unit as the drive unit for the X stage is provided. XY stage.

FIG. 2 shows a positioning stage device E _{2 according} to a second embodiment, which is a pressurizing chamber 1 of the first embodiment.
2b, a pocket (recess) 22f is provided in an opening 22c which is an opening of the pressurizing chamber 22b, and the pocket 22f is connected to an exhaust line 22g serving as a leak gas exhaust means, and a leak is generated from the pressurizing chamber 22b. A part of the helium gas to be discharged is directly discharged to the outside of the exposure chamber 1.

Exposure chamber 1, guide member 2, Y stage 3,
Since the linear motor 11 and the like are the same as in the first embodiment, they are denoted by the same reference numerals and description thereof is omitted.

Since the amount of helium gas leaking from the pressurizing chamber 22b is too large, the atmospheric pressure in the exposure chamber 1 changes rapidly, and local unevenness of the pressure in the exposure chamber 1 tends to occur. In some cases, the above-described trouble can be avoided by discharging a part of the leak directly to the outside of the exposure chamber 1. Further, by controlling the exhaust speed of the helium gas discharged from the exhaust line 22g, the purity of the helium gas in the exposure chamber 1 can be maintained.

The other points are the same as in the first embodiment.

Next, an embodiment of a method of manufacturing a semiconductor device using the above-described exposure apparatus will be described. FIG. 3 shows a manufacturing flow of a semiconductor device (a semiconductor chip such as an IC or an LSI, or a liquid crystal panel or a CCD). In step 1 (circuit design), the circuit of the semiconductor device is designed. Step 2 is a process for making a mask on the basis of the circuit pattern design. In step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon.
Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. 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, 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. 4 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 15
In (resist processing), a photosensitive agent is applied to the wafer. Step 16 (exposure) uses the above-described exposure apparatus to print and expose the circuit pattern of the mask onto the wafer. 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 the manufacturing method of this embodiment, it is possible to manufacture a highly integrated semiconductor device, which has been conventionally difficult to manufacture.

[0047]

Since the present invention is configured as described above, it has the following effects.

It is possible to effectively avoid contamination of the atmosphere in a sealed chamber such as an exposure chamber due to gas leaking from a driving section or a bearing section of the positioning stage device, thereby reducing running costs and exposing uneven exposure. Thus, it is possible to realize an exposure apparatus capable of performing extremely high-precision exposure without any problem.

The use of such an exposure apparatus can greatly contribute to higher definition and lower cost of semiconductor products.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an exposure apparatus according to a first embodiment.

FIG. 2 is a schematic sectional view showing an exposure apparatus according to a second embodiment.

FIG. 3 is a flowchart showing a semiconductor manufacturing process.

FIG. 4 is a flowchart showing a wafer process.

FIG. 5 is a schematic sectional view showing a positioning stage device according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exposure room 2 Guide member 3 Y stage 3a Square mirror 4 Wafer holding board 5 Magnet 11 Linear motor 12 Air cylinder 12b, 22b Pressurizing room 12c, 22c Opening 14 Air supply line 13, 22g Exhaust line 22f Pocket

Claims (10)

[Claims] 1. A moving stage movable along guide means provided in a sealed chamber, a driving unit for moving the moving stage, and an atmosphere control for controlling the sealed chamber to a predetermined gas atmosphere. Means, wherein the drive section includes a fluid pressure cylinder using a fluid having the same component as the predetermined gas as a drive medium. 2. The positioning stage device according to claim 1, wherein the fluid pressure cylinder has an opening sealed by a non-contact gas seal. 3. The positioning stage according to claim 1, wherein the atmosphere control means is configured to control the purity of the atmosphere in the sealed chamber by using a leak gas leaking from the fluid pressure cylinder. apparatus. 4. An atmosphere control means having an air supply means, wherein the purity of the atmosphere in the sealed chamber is controlled using a supply gas supplied from the air supply means and a leak gas leaking from a fluid pressure cylinder. The positioning stage device according to claim 1, wherein the positioning stage device is provided. 5. Leak gas exhaust means for directly discharging a leak gas leaking from a fluid pressure cylinder to the outside of the sealed chamber is provided, and the leak gas exhaust means adjusts an exhaust speed of the leak gas to adjust the exhaust rate of the sealed chamber. The positioning stage device according to any one of claims 1 to 4, wherein the positioning stage device is configured to control the purity of the atmosphere. 6. The positioning stage device according to claim 1, wherein the predetermined gas is helium gas. 7. The positioning stage device according to claim 1, wherein the drive section is constituted by a fine movement actuator composed of a linear motor and a coarse movement actuator composed of a fluid pressure cylinder. 8. An atmosphere control means, an air supply means for supplying a supply gas to the sealed chamber, an exhaust means for exhausting the sealed chamber, a pressure detecting means for detecting a pressure of an atmosphere in the sealed chamber, and an output thereof. The positioning stage device according to any one of claims 1 to 7, further comprising a controller that controls at least one of the air supply unit and the air exhaust unit based on the following. 9. The positioning stage device according to claim 1, further comprising magnetic means for maintaining a non-contact between the moving stage and the guide means by magnetic repulsion. 10. An exposure apparatus comprising: the positioning stage device according to claim 1; and an exposure unit that exposes a substrate positioned by the positioning stage device.