JP2001025227A - Linear motor, and stage system and aligner provided with the motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently remove heat from a linear motor coil without damaging protective film on the surface of the coil by providing a jacket with double structure composed of an inner jacket and an outer jacket and letting different types of coolants to flow through the inner jacket and the outer jacket of the coil. SOLUTION: A double jacket is constituted, for example, of a coil inner jacket 4 and 4' which embraces a coil 1 and is supplied in its internal space with a coolant and an outer jacket 9 and 9', which is supplied outside the jacket with coolant. Inert gas is let to flow through the coil inner jacket 4 and 4' so that the protective film on the coil is not damaged. A coolant, regardless of its being activated or inert, satisfactory in cooling efficiency is let to flow through the outer jacket 9 and 9'. Thus insufficiency in cooling capability due to adoption of an inert coolant inferior in cooling capability for the coil inner jacket 4 and 4' can be made up by letting coolant satisfactory in cooling efficiency flow through the jacket 9 and 9'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor suitably used for an apparatus for performing precise positioning such as a semiconductor exposure apparatus and a high-precision processing machine.

[0002]

2. Description of the Related Art In a positioning device on the order of nanometers used in a semiconductor exposure apparatus or a high-precision processing machine, heat generated from a linear motor as a driving source has a bad influence on positioning. Factors such as thermal deformation of the structure due to heat generation or a measurement error of the laser interferometer in position measurement due to an increase in air temperature deteriorate the positioning accuracy of the device equipped with the linear motor. For example, a low-thermal-expansion material of 100 mm (coefficient of thermal expansion 1 × 10 ⁻⁶ ) is 1 even if the temperature changes by 1 ° C.
It is deformed by only 00 nm, and even if the change in air temperature in the optical path of the optical interferometer is 1 ° C. or less, an error of 100 nm may occur in the measured value. Therefore, it is necessary to cool the linear motor, in particular, to recover the heat generated from the linear motor, as a measure for preventing such a temperature change.

On the other hand, with an increase in the performance of the apparatus, an increase in the output of the linear motor is required. Therefore, when the current flowing through the coil is increased, the amount of heat generated also greatly increases. Therefore, it is necessary to further increase the cooling capacity. It is also important to increase the cooling capacity of the coil in order to prevent an increase in coil resistance and breakage of the coil wire due to a rise in coil temperature.

FIG. 4 is a diagram showing the configuration of a conventional linear motor provided with a cooling means. The linear motor shown in FIG. 1 has a permanent magnet 3 fixed to a coil 1 and yokes 2 on both sides thereof.
3 ', the coil 1 is a thin sheet 4, 4'
And a jacket 8 composed of a frame 5. The coil 1 is fixed to the frame 5 by a fixture 7. Here, heat generated from the coil is recovered by flowing a refrigerant through the internal space 6 of the jacket 8.

[0005]

In the above conventional example,
In order to increase the cooling capacity of the coil by keeping the flow rate of the refrigerant constant, it is effective to use a refrigerant with high heat absorption efficiency, but on the other hand, the refrigerant is in direct contact with the coil where high-voltage current is flowing Therefore, if the refrigerant is activated, the protective film on the coil surface may be damaged, causing electrical breakdown and losing the function of the linear motor. In order to prevent this, a chemically inert refrigerant is used for cooling the coil, but in general, the inert refrigerant has poor heat absorption efficiency. The ability could be insufficient.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has an effect on positioning accuracy by efficiently removing heat from a coil without damaging a protective film on the surface of a linear motor coil. An object of the present invention is to provide an excellent stage apparatus, exposure apparatus, device manufacturing method, and the like using this linear motor by eliminating thermal deformation, measurement errors of a laser interferometer, and the like.

[0007]

In order to achieve the above object, the present invention provides a linear motor having a coil and a jacket covering the coil and supplying a coolant to an internal space. It has a double structure and is characterized by flowing two kinds of refrigerants having different properties through the inner jacket and the outer jacket of the coil. Such a double jacket is, for example, by adding an outer jacket to which a coolant is supplied outside the jacket to a conventional linear motor having a coil and a jacket that covers the coil and is supplied with a coolant to an internal space. can get. An inert refrigerant is allowed to flow through the inner jacket so as not to damage the protective film on the coil surface. A refrigerant having a high cooling efficiency is flowed through the outer jacket regardless of whether it is active or inactive.

[0008] The stage device of the present invention is characterized by having the linear motor having the above-described structure as a driving mechanism. The exposure device of the present invention mounts a substrate on the stage device and exposes the substrate to light. It is characterized by having a means for performing. Further, a device manufacturing method according to the present invention is characterized in that a device is manufactured using the above exposure apparatus.

[0009]

According to the present invention, an inert refrigerant is used in the inner jacket of the coil to prevent the insulating layer on the coil surface from being damaged. Insufficient cooling capacity due to the use of an inert refrigerant having generally low cooling capacity in the coil inner jacket can be compensated for by flowing a coolant having high cooling efficiency through the outer jacket of the double jacket. Therefore, according to the present invention, the heat generated from the linear motor coil is absorbed without damaging the insulating layer on the coil surface, and the influence on the accuracy, the thermal deformation of the structure, and the measurement error of the laser interferometer are eliminated. An excellent stage apparatus, exposure apparatus, device manufacturing method, and the like using the linear motor can be provided.

[0010]

(Embodiment 1) FIG. 1 is a diagram showing a configuration of a single-phase linear motor according to an embodiment of the present invention. FIG. 2 is an exploded view for explaining the internal structure of the linear motor of FIG. 1, and FIG.
3 is a perspective view of the linear motor of FIG.

In FIG. 1, 1 is a coil through which a driving current flows, 2 is two yokes constituting a magnetic circuit, and 3 is a permanent magnet fixed to each yoke 2 and having different magnets arranged facing each other. is there. Reference numerals 4 and 4 'denote sheets arranged with the coil 1 interposed therebetween. Reference numeral 5 denotes a frame for supporting the two sheets 4, 4'. Make up the jacket. 6 is an internal space of the inner jacket, and 7 is a fixture for fixing the coil 1 to the frame 5. 9,
9 'is a member constituting the outer jacket of the double jacket which is a characteristic member of the present embodiment, and 10 is an internal space of the outer jacket. Sheets 4, 4 'and 9, 9'
And the frame 5 are fixed with an adhesive or a bolt. Seat 4, 4 ', Frame 5, Seat 9, 9'
Is a non-magnetic material, and is preferably an electrically high-resistance material or an insulator material, for example, a polymer resin material or a ceramic material.

2 and 3, reference numeral 20 denotes a coil 1
(2), 21 are small holes for leading the lead wire 20 from the inside of the jacket to the outside. This small hole 21
After the lead wire is drawn out, the small holes are hermetically sealed with an adhesive or the like so that the refrigerant does not leak from the small holes. 22 and 23 are a supply pipe and a recovery pipe for the refrigerant connected to the inner jacket. The refrigerant is supplied from the supply pipe 22, flows through the inner jacket, receives the heat generated by the coil, and is recovered from the recovery pipe 23. A protective film is formed on the coil surface so that the conductor of the coil 1 does not directly contact the refrigerant, but in order to prevent damage to the protective film, an inert refrigerant is supplied even if the refrigerant is liquid or gas. . 24 and 25 are a supply pipe and a recovery pipe for the refrigerant connected to the outer jacket. The refrigerant is supplied from the supply pipe 24 and flows in the outer jacket, and receives the heat of the coil from the refrigerant flowing in the inner jacket via the sheets 4 and 4 ′,
It is collected from the collection pipe 25. The coolant supplied to the outer jacket may be a liquid or a gas. Although it is not necessary to use an inert refrigerant, a refrigerant having high heat absorption efficiency is preferable.

In the above configuration, when an electric current is applied to the coil 1 located in the space between the permanent magnets 3 and 3 'generating the fixed magnetic field, Lorentz force acts, and the coil 1 and the permanent magnets 3 and 3' 1 relatively move vertically in the plane of the paper.
For example, in the upper half of the figure, when the magnetic field flows from left to right on the page and current flows from the back of the page to the front,
A force corresponding to the magnitude of the current acts on the coil 1 in the upward direction on the paper surface and on the permanent magnets 3 and 3 'in the downward direction, and each moves relatively. By passing a predetermined current through the coil in this way, the yoke (that is, the permanent magnets 3, 3 ') and the structure to which the coil is fixed are driven. In this embodiment, a so-called moving magnet type linear motor is used, in which the coil 1 is fixed to the frame 5, the coil side is a stator, and the yoke side holding the permanent magnet is a mover. And the mover may be reversed. Also, in FIG.
To the frame 5, but the seats 4, 4 '
May be fixed.

FIG. 5 shows an example of an exposure apparatus having a wafer stage using the linear motor described in the first embodiment. In the figure, reference numeral 51 denotes a wafer stage top plate (tilt stage) having a tilt mechanism, on which a semiconductor wafer 53 is mounted. Aori stage 51
An illumination system 57 having a light source and an illumination optical system, a reticle 58 provided with a pattern to be transferred to a wafer, and a reduction projection optical system 59 for reducing and projecting the pattern of the reticle 58 at a predetermined magnification are provided above the optical system. I have.

The configuration of the wafer stage will be described.
Reference numeral 54 denotes a guide that restricts the tilt stage 51 only in the horizontal direction, and allows movement in the Z direction, the tilt direction, and the Ζ-axis rotation direction by using, for example, a hydrostatic bearing. 56 is a base. 55 is the first embodiment described above.
The position or inclination of the stage 51 in the Ζ direction, which is the direction of gravity, is adjusted with respect to the base 56 by driving three linear motors (the remaining one is not shown). be able to. Also, by measuring the position and inclination of the stage 51 in the Ζ direction,
The position and inclination of the wafer stage in the Ζ direction can be controlled.

According to the present embodiment, since the cooling efficiency of the linear motor is increased and almost all of the heat generated from the coil is recovered, the heat generated from the linear motors 25a and 25b is transmitted to the stage 51 to increase the temperature. Also, since the ambient temperature is not increased, the positioning accuracy of the wafer stage can be significantly improved, and thus, exposure transfer can be performed with higher precision than ever before.

(Embodiment 3) FIG. 6 shows a production flow of a semiconductor device (a semiconductor chip such as an IC or an LSI, or a liquid crystal panel or a CCD) using the above exposure apparatus. 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,
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. 7 shows a detailed flow of the wafer process. Step 11 (oxidation) oxidizes the wafer's surface. Step 12 (CVO) 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 a mask circuit pattern on the wafer by exposure. Step 1
In step 7 (development), the exposed wafer is developed. Step 1
In step 8 (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.

[0019]

According to the present invention, the primary cooling is performed without damaging the protective film on the coil surface by making the coil jacket a double jacket structure and flowing an inert refrigerant through the coil inner jacket. The heat that could not be completely removed by the primary cooling, in which an inert refrigerant having a poor heat absorption efficiency was flown, was secondarily cooled by the outer jacket, so that the overall cooling efficiency could be improved. As a result, it becomes possible to pass more electric power through the coil,
The speed of the stage device was increased by improving the thrust of the linear motor. In addition, the heat generated from the coil was reduced, so that the structure was thermally deformed due to the heat of the stage device.
The measurement error of the laser interferometer was reduced, and the accuracy of the stage device was improved.

[Brief description of the drawings]

FIG. 1 is a top view illustrating a linear motor according to a first embodiment of the present invention.

FIG. 2 is an exploded view showing a jacket configuration of the linear motor of FIG.

FIG. 3 is a perspective view illustrating an appearance of the linear motor of FIG.

FIG. 4 is a top view illustrating a conventional linear motor.

FIG. 5 is a configuration diagram of an exposure apparatus having a stage according to a second embodiment of the present invention.

FIG. 6 is a view illustrating a flow of manufacturing a semiconductor device according to a third embodiment of the present invention.

FIG. 7 is a diagram showing a detailed flow of the wafer process of FIG. 6;

[Explanation of symbols]

1: coil, 2: yoke, 3, 3 ': permanent magnet, 4,
4 ': inner jacket sheet, 5: frame, 7: fixture, 9, 9': outer jacket sheet.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02K 3/24 H02K 9/00 Z 9/00 H01L 21/30 503A F-term (Reference) 5F031 CA02 CA05 FA01 FA02 FA07 GA64 HA38 HA53 JA01 KA06 KA07 LA08 MA27 PA11 PA30 5F046 CC01 5H603 AA12 AA13 BB01 BB09 BB15 CA01 CA02 CA05 CB01 CC19 5H609 BB08 PP02 PP05 PP08 QQ07 RR32 RR74 5H641 BB06 BB18 H02 GG19H02 GG19H

Claims (8)

[Claims] 1. A linear motor having a coil and a jacket covering the coil and supplying a coolant to an internal space, wherein the jacket has a double jacket structure including an inner jacket and an outer jacket, wherein the inner jacket and the outer jacket of the coil are provided. A linear motor characterized in that two kinds of refrigerants having different properties are supplied to the motor. 2. The linear motor according to claim 1, wherein the refrigerant supplied to the inner jacket is an inert refrigerant. 3. The double jacket is formed by overlapping a frame for fixing the coil and two sheets on both sides of the frame with respect to the driving direction of the linear motor. 3. The linear motor according to claim 1, wherein the linear motor is a motor. 4. The linear motor according to claim 1, wherein said double jacket is made of a non-magnetic material and made of an electrically high-resistance material or an insulating material. 5. The linear motor according to claim 1, further comprising a yoke to which a magnet facing the coil is attached with the double jacket interposed therebetween. 6. A stage device comprising the linear motor according to claim 1 as a drive mechanism. 7. An exposure apparatus, comprising: means for mounting a substrate on the stage device according to claim 6, and exposing the substrate. 8. A device manufacturing method, comprising manufacturing a device using the exposure apparatus according to claim 7.