JP2007142168A - Immersion lithography system having wafer sealing mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an immersion which can control and surround an immersion lens solution in operating steps of an immersion lithography system. <P>SOLUTION: A solution and seal ring 418 are provided. The solution is an immersion solution for use on a wafer in immersion lithography steps. The seal ring 418 covers the predetermined part of the edge of the wafer. The solution is prevented from being leaked from the covered edge of the wafer when used in the immersion lithography steps. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an immersion lithography process used in the manufacture of semiconductor devices, and more particularly to an immersion lithography system with the ability to control and surround immersion lens liquid in the operation process of an immersion lithography system.

  Since the manufacturing process of the VLSI is manufactured by printing predetermined circuits and elements on the surface of a semiconductor wafer (substrate), a very large number of photolithography process steps are required. A conventional photolithography system is composed of a plurality of subsystems including a light source, an optical transmission element, a photomask, and an electronic control unit. Then, a predetermined circuit pattern drawn on the photomask is projected onto the semiconductor wafer covered with the photosensitive film (photoresist) by these systems. As VLSI technology improves, circuit geometries become finer and denser, which requires the use of lithographic equipment with even lower resolution (smaller feature sizes) projection and printing capabilities. It was. In order to meet the demand for such a device, an analysis level having a feature size smaller than 100 nm is currently provided. With the development of the device generation, the demand for the apparatus has increased at the same time, and the degree of feature analysis required in the photolithography process has increased to a level of 65 nm or less.

In order to greatly improve the degree of analysis, the advantages of immersion lithography process technology have already been used for some time. In immersion lens lithography, a gap between an objective lens element of a light projection system and a surface of a semiconductor wafer (substrate) is filled with a liquid medium in an exposure process of a photoresist pattern printing process. Then, by using the liquid medium as an immersion lens, the refractive index of the transmitted light is improved and the analysis capability of the lithography system is improved. Rayleigh's resolution formula describes this phenomenon as R = k ₁ λ / N. A. It can be expressed as R (feature size resolution) is k ₁ (predetermined process constant), λ (wavelength of transmitted light) and N.I. A. It varies depending on the difference in the numerical aperture of the light projection system. It should be noted here that N.I. A. Is also a function of refractive index. A. = N sin θ. The variable n is the refractive index of the liquid medium between the objective lens and the wafer substrate, and θ is the incident angle of the transmitted light with respect to the lens.

  It can be seen that the numerical aperture of the projection system increases when the angle of incidence is fixed and the refractive index (n) is large. And it provides a large degree of analysis which is a small R value. In conventional immersion lithography systems, deionized water has been used as the immersion liquid between the objective lens and the wafer substrate. Taking transmission light with a wavelength of 193 nm as an example, the refractive index of air is close to 1.00, whereas deionized water has a refractive index close to 1.44 at 20 ° C. As can be seen from the above, when deionized water is used as the immersion liquid, the resolution of the photolithography process is greatly improved.

  FIG. 1 is a cross-sectional view showing a conventional immersion lithography system. The immersion printing portion 100 of the lithographic system shown in the figure includes a movable wafer chuck / stage 102 that couples the wafer chuck / stage 102 and a vacuum channel 104 to place a photoresist coated wafer 106 on the wafer chuck 102. Support and fix. As shown in FIG. 1, an immersion liquid 108 placed on a photoresist coated wafer 106 replaces the entire space between the objective lens element 110 of the lithographic light projection system and the wafer. The immersion liquid 108 contacts the top surface of the photoresist coated wafer 106 and the bottom surface of the objective lens element 110 directly.

  Two liquid tanks are in direct contact with the liquid phase of the water immersion area 109. Then, the liquid supply tank 112 supplies and injects the immersion liquid and puts it into the immersion area 109. The immersion area 109 is provided under the objective lens element 110. The injected immersion liquid is held by the capillary force of the immersion area or is surrounded by a fixing device accompanying the movement of the lens. In general, the thickness of the immersion liquid is between about 1-2 mm. Further, the immersion liquid flowing out from the immersion lens 108 is recovered or received by the liquid recovery tank 114. It should be noted here that the immersion liquid flows from the liquid supply tank 112 through the immersion area 109 to the liquid recovery tank 114. By combining mechanical hardware and electrical / electronic control devices, these devices can direct the flow of immersion liquid as described above. As shown in FIG. 1, the downward arrow described above the objective lens element 110 of the lithography system indicates the direction in which the patterned image exposure beam 116 is transmitted, and the exposure beam 116 is the objective lens. The element 110 is irradiated and reaches the photoresist coated wafer 106 through the immersion lens 108. In a typical operation process for immersion lithography patterning of a photoresist coated wafer 106, the wafer chuck 102 is moved to provide immersion liquid 108, liquid supply tank 112, liquid recovery tank 114, objective lens element 110 and patterned image exposure. The exposure target area of the wafer is moved to a fixed position in the lithography system architecture such as

  FIG. 1 shows the structure of a typical immersion lithography system. With this structure, the immersion lithography process can be performed efficiently. However, there have been several problems with the entity structure and process steps that affect the quality of the immersion lithography process and the system operating efficiency. These problems are evident when looking at FIG. FIG. 2 is a cross-sectional view illustrating an exemplary immersion lithography system similar to FIG. However, this hardware element is installed at the edge of the wafer substrate unlike FIG. As shown in FIG. 2, the immersion printing portion 200 of the lithography system supports the photoresist coated wafer 206 on the wafer chuck 202 by coupling the movable wafer chuck / stage 202 and the vacuum channel 204 together. Can be fixed. Then, as shown in FIG. 2, an immersion liquid 208 placed on the photoresist coated wafer 206 replaces the entire space between the objective lens element 210 of the lithographic light projection system and the wafer. The immersion liquid 208 is in direct contact with the top surface of the photoresist coated wafer 206 and the bottom surface of the objective lens element 210. The two immersion liquid tanks, that is, the immersion liquid supply tank 212 and the immersion liquid recovery tank 214 are in direct contact with the immersion liquid 208.

  As shown in FIG. 2, by placing immersion liquid 208 at the edge of wafer substrate 206, processing can be performed on the photoresist region at the edge of the wafer. However, at the edge of the wafer, the immersion liquid flow generally differs from the structure shown in FIG. 1, which is a closed loop that flows from the liquid supply tank 212 through the immersion area 209 to the immersion liquid recovery tank 214. In FIG. When processing is performed at the edge of the substrate, the immersion liquid flows out to the outside through another channel 215. This additional flow path allows immersion liquid to flow along the edge of the wafer substrate 206 and the movable wafer chuck / stage 202 to the immersion lens 208 and the loop system of the immersion liquid tank, so that the immersion liquid is recovered. It stops flowing to the tank 214. The immersion liquid itself, which cannot be controlled or surrounded in this way, does not affect the quality of the immersion lithography process, but does affect the operation efficiency. When the immersion liquid flowed out of the immersion area 209 and the immersion liquid tank, the immersion liquid was wasted without being completely recovered. In addition, the mechanical or electronic elements of the wafer chuck and other parts below the chuck could get wet by the additional flow path 215 of immersion liquid under unforeseen circumstances. This unexpected wetting and flow could contaminate the system and could shorten the operating life of the system hardware and electronic components. Therefore, to solve these problems, immersion lithography system designers need to spend more time and effort to provide a design and structure suitable for overflowing excess immersion liquid.

  In addition, when the immersion liquid 208 is installed on the edge of the wafer, a problem may occur in the immersion lithography process. In normal wafer processing in a general semiconductor manufacturing process apparatus, fine particles gathered on the edge of the wafer and contamination was likely to occur. This is due to the fact that the edge of the wafer is in close contact with the production process apparatus and the production process, and is closer to the source of fine particles than the inside of the wafer substrate. As shown in FIG. 2, when the wafer substrate edge 206 is placed under the immersion area 209 by the wafer chuck / stage 202, the immersion liquid is contacted with particulates on the wafer substrate edge 206. As a result, fine particles may fall off the wafer 206 and float in the immersion liquid 208. Due to the adverse effect of the fine particles, the image pattern transferred onto the wafer substrate in the immersion lithography exposure process may be distorted or disturbed. In addition, the deposition of fine particles on the surface of the wafer substrate can adversely affect various subsequent manufacturing process operations performed on the wafer. Therefore, the immersion liquid flowing into the liquid recovery tank 214 of the immersion liquid and the excessive flow 215 flowing out of the immersion area 209 cannot prevent adverse effects of the fine particles on the immersion lithography process and each subsequent manufacturing process. It was.

  Therefore, there is a need for an improved system capable of sealing and controlling immersion liquid in the immersion area during the entire operation of the immersion lithography process. This improved system can minimize particulate entering the immersion liquid so that the immersion liquid does not contact the particulate contamination area. This system then prevents distortion and defects from occurring in order to complete the pattern and photoresist image on the wafer.

  An object of the present invention is to provide an immersion liquid that performs an immersion lithography process on a wafer and a seal ring that covers a predetermined portion of the edge of the wafer so that the immersion liquid does not leak from the predetermined portion that covers the edge of the wafer. An immersion lithography system comprising:

  To achieve the above object, an immersion lithography system having a wafer sealing mechanism of the present invention comprises a liquid and a seal ring. This liquid provides an immersion liquid for performing an immersion lithography process on the wafer. The seal ring covers a predetermined portion of the wafer edge. Then, the liquid is used for the immersion lithography process so that the immersion liquid does not leak from the cover portion at the edge of the wafer.

  As can be seen from the foregoing, the immersion lithography system having the wafer sealing mechanism of the present invention can be easily implemented in conventional system design and processes, as well as in equipment and operation. The method and apparatus of the present invention can be easily implemented in advanced immersion lithography process technology applying a conventional exposure wavelength of 150 to 450 nm and in future systems utilizing shorter wavelengths. The method and system of the present invention can provide high stability and excellent quality for advanced semiconductor device manufacturing.

The present embodiment provides an immersion lithography system that seals and controls immersion liquid within the immersion area during the entire period of the lithography exposure process. The system includes a seal ring device and seals and controls the immersion liquid into the wafer substrate and the immersion liquid bath by covering the edge of the wafer substrate. Then, the seal ring carrier is used to install or remove the seal ring. In addition, embodiments are disclosed that apply this seal ring in multiple immersion lithography systems. This embodiment further discloses an example design of a seal ring carrier that can be applied in multiple immersion lithography systems.

  The seal ring device of this embodiment is a soft material made of rubber, plastic, Mylar (registered trademark), Delrin (registered trademark), Teflon (registered trademark), or other similar materials that can be used for seals. A thin ring of material. In order to form this seal ring, its thickness is made smaller than the distance between the surface of the wafer substrate and the objective lens element of the light projection system, which is also the working distance of the immersion lens. Depending on the size of the inner diameter (defining the open area) of the seal ring, the seal ring can cover / shield part of the outer edge and circumference of the wafer substrate, exposing the target position on the surface of the wafer substrate in the immersion lithography process To do. The outer diameter (outer edge) size of the seal ring is large enough to overlay the seal ring material on the outer edge of the wafer substrate, leaving a portion of the wafer substrate adjacent to the wafer chuck / stage in a contact-sealed condition.

  FIG. 3 is a cross-sectional view showing a state when the seal ring is coupled to immersion lithography. As shown in FIG. 3, the immersion printing portion 300 of the lithography system couples a movable wafer chuck / stage 302 and a vacuum channel 304 together to support and secure a photoresist coated wafer 306 on the wafer chuck 302. To do. Then, a groove 307 is formed on the upper layer surface of the wafer chuck / stage 302, and a space for installing the wafer substrate 306 in which the thickness and circumference of the groove 307 matches the thickness and circumference of the wafer substrate is provided. Thereby, the upper surface of the wafer substrate 306 is formed in the same plane as the upper surface of the portion of the wafer chuck / stage 302 where no groove is formed. Then, the immersion liquid 308 placed on the photoresist coated wafer 306 replaces the entire space between the wafer and the objective lens element 310 of the lithographic light projection system. The immersion liquid is in direct contact with the top surface of the photoresist coated wafer 306 and the bottom surface of the objective lens element 310. Two immersion liquid tanks (immersion liquid supply tank 312 and immersion liquid recovery tank 314) and other elements confine immersion liquid 308 in the space between the wafer and lens element 310. A liquid container is formed by two immersion liquid tanks and their associated elements.

  As shown in FIG. 3, the immersion liquid 308 is placed on the substrate edge of the wafer 306 and performs a process reaction on the photoresist region. A seal ring 318 placed at the edge on the surface of the wafer substrate 306 is placed in direct contact with the outer edge of the wafer substrate 306 and overlapped, and the seal ring 318 is a portion 319 of the edge of the wafer substrate 306 adjacent to the wafer chuck / stage. Contact. The seal ring 318 of this embodiment confines the immersion liquid in the immersion area 309. The seal ring 318 can prevent the immersion liquid from flowing out of the immersion area 309 and the liquid supply tanks 312 and 314. When the immersion liquid is confined by the seal ring 318, the flow and use of the immersion liquid can be easily controlled and managed. Therefore, in the immersion lithography process, the flow and use of the immersion liquid installed on both the inside and the edge of the wafer substrate can be easily controlled and managed. This minimizes the loss and waste of the immersion liquid and maintains the constancy and stability in the liquid flow dynamics within the immersion area 309 and the loop system of the immersion liquid tank. It should be noted that if the outer edge of the wafer substrate 306 is covered by the seal ring 318, the fine particles on the edge of the wafer substrate 306 can be prevented from contaminating the immersion liquid and the surface of the wafer substrate 306. is there. As a result, the immersion liquid and the immersion area 309 are kept clean and fine particles do not cause interference or distortion in the immersion lithography process. Further, when the fine particles are hermetically covered with a seal ring, the fine particles are prevented from sticking to the surface of the internal wafer substrate, and there is an advantage that no damage occurs in the subsequent process.

  FIG. 4 is a cross-sectional view illustrating a state where a seal ring is installed in an immersion lithography system according to another embodiment. As shown in FIG. 4, an immersion printing portion 400 of a lithography system couples a movable wafer chuck / stage 402 and a vacuum channel 404 together to support a photoresist coated wafer 406 on the wafer chuck / stage 402. And fix. A double layer groove is formed on the upper surface of the wafer chuck / stage 402. The first layer groove 405, which is a double layer groove forming the wafer chuck / stage 402, provides a space for placing the wafer substrate 406 by matching the thickness and circumference with the thickness and circumference of the wafer substrate 406. Then, a coplanar surface with the upper surface of the first groove is formed on the upper surface of the wafer substrate 406. By forming the second layer groove 407 and inserting the seal ring 418 on the circumference of the second layer groove, the seal ring 418 and the outer edge of the wafer substrate 406 are brought into contact with each other, and the seal ring 418 is overlapped with the wafer substrate. A part of the second layer groove 407 of the wafer chuck / stage 402 adjacent to the edge of the wafer. The upper end of the seal ring 418 placed in the groove forms a coplanar surface with the outer edge of the upper surface where the groove portion is not formed in the wafer chuck / stage 402 due to the depth of the second layer groove 407.

  As shown in FIG. 4, the immersion liquid 408 is installed near the edge of the wafer substrate 406 and performs a process reaction on the photoresist region. An immersion liquid 408 placed on the photoresist coated wafer 406 replaces the entire space between the wafer and the objective lens element 410. Due to the double step structure of the wafer chuck / stage recess, the seal ring 418 can seal the immersion liquid in the immersion area 409. FIG. 4 shows a state in which the immersion liquid does not leak to the outside. As shown in FIG. 4, the immersion lithography system of the present embodiment can not only efficiently control the flow and use of the immersion liquid, but also particles on the edge of the wafer can cause the wafer surface and the immersion lithography system to be controlled. Contamination can be minimized.

  It should be noted that the design and configuration of the wafer chuck / stage and seal ring can be varied to more effectively seal the immersion liquid to the immersion area. For example, an elastic seal ring is installed to extend the seal ring until it exceeds the range that covers the wafer chuck / stage, and extends downward to cover a portion of the wafer chuck / stage (not shown). You can also In another embodiment, a semi-rigid and smooth seal ring is placed on a wafer chuck / stage having a small diameter, and the seal ring is stretched on the same plane so that the seal ring is the outer edge of the wafer chuck / stage. You may install so that it may exceed (not shown).

  In this embodiment, the seal ring can be set on the wafer substrate and the wafer chuck / stage by the seal ring carrier, or the seal ring can be removed from the wafer substrate and the wafer chuck / stage. The seal ring carrier of this embodiment includes an extendable mechanical arm in the immersion printing portion of the immersion lithography system, and moves the arm to a position directly in front of the seal ring to install or remove the seal ring. can do. Furthermore, the arm of the seal ring carrier can be moved vertically to the position directly in front of the seal ring so that the seal ring on the wafer chuck / stage can be installed or removed. When the seal ring carrier mechanical arm is in a position to adsorb the seal ring, the seal ring is removed from the wafer chuck / stage, and the seal ring carrier mechanical arm is retracted and moved to a location other than the wafer chuck / stage. Save and replace seal rings. A vacuum channel is formed inside the seal ring carrier, and the vacuum channel has a small vacuum opening at a predetermined position, and the suction operation of sucking, picking up or exchanging the seal ring is performed by the vacuum suction force of the opening.

  FIG. 5 is a cross-sectional view illustrating a state in which a seal ring carrier is applied to an immersion lens lithography system according to an embodiment of the present invention. In the assembly of the wafer chuck / stage, as shown in FIG. 5, a seal ring 418 is installed at a process position on the upper surface of the wafer chuck / stage 402 and the wafer substrate 406. The seal ring transport assembly 500 is installed directly above the seal ring 418. Seal ring transport assembly 500 connects seal ring carrier 502 to seal ring carrier arm 504. Many vacuum channels 506 are formed inside the seal ring carrier 502 and the seal ring carrier arm 504. A seal ring contact point 508 is installed on a predetermined position of the seal carrier, and a number of openings having a vacuum suction force are formed at the seal ring contact point 508 so that the seal ring carrier arm 504 of the seal ring carrier 502 contacts the seal ring. When it is moved, the seal ring is sucked, picked up or moved by the opening of the vacuum suction force. It should be noted here that the seal ring transport assembly 500 can expand and contract on the same XY plane. The seal ring transport assembly 500 moves up and down in the vertical direction or the z-axis direction, expands and contracts to a predetermined position, and contacts the seal ring 418. The seal ring transport assembly 500 can move the seal ring 418 to a storage location or to a location other than the wafer chuck / stage assembly.

  6A to 6D are bottom views showing a seal ring carrier according to another embodiment of the present invention. The functions of the seal ring carriers shown in FIGS. 6A to 6D are substantially the same as those described above, but the external structure and shape of each design are different. The seal ring carrier shown in FIG. 6A is formed in an annular structure. The side of the seal ring carrier arm 602 is connected to a ring-shaped seal ring carrier 604. The circumference and diameter of the annular seal ring carrier 604 is exactly the same size as the seal ring. The vacuum channel 606 formed in the seal ring carrier arm 602 and the seal ring carrier 604 guides and distributes the vacuum suction force to a vacuum opening 608 at a predetermined seal ring contact point provided on the seal ring carrier 603. Let

  FIG. 6B shows a foldable cross-shaped seal ring carrier. The side of the seal ring carrier arm 602 is connected to a foldable cruciform seal ring carrier, and the foldable cruciform seal ring carrier includes a fixed arm 604 and a foldable arm 605. When the seal ring carrier arm 602 extends to the operating position, the axis of the foldable arm 605 is perpendicular to the fixed arm 604 to form a cross shape so that the foldable arm 605 is not folded. The vacuum channel 606 formed in the seal carrier arm 602 and the two cross arms 604, 605 guides and distributes the vacuum suction force to the vacuum opening 608 at the seal ring contact point provided on the seal ring carrier arms 604, 605. Let The structure of the seal ring carrier arms 604 and 605 and the arrangement of the vacuum opening 608 bring the vacuum opening into contact with the seal ring 610. It should be noted here that the foldable seal ring arm 605 must be folded to a cross position where it cannot be folded in order to perform the pick-up and move operation of the seal ring 610. The folding position of the operable cross arm 605 is a position facing the fixed arm 604 when the foldable arm 605 is folded in the f direction around the point p. Thus, the foldable characteristic of the seal ring carrier enables the seal ring carrier arm to be easily moved and stored, and the seal ring carrier of the immersion lithography system can be made small and simple in structure. .

  FIG. 6C shows another foldable seal ring carrier. A seal ring carrier having a foldable structure including a fixed arm 604 and two foldable arms 605 a and 605 b is connected to a side of the seal ring carrier arm 602. The vacuum channel 606 formed in the seal ring carrier arm 602 and the two foldable arms 605a, 605b annularly forms a vacuum opening 608 in the vacuum channel, and this annular circumference, diameter is the same as that of the seal ring 610. Is exactly the same. The two foldable arms 605a, 605b need not be the same size and length, but the two foldable arms 605a, 605b move at the fold center point p and are connected to the seal ring carrier arm 602; The folding center point p is located on the side of the seal ring carrier arm 602. When the seal ring carrier arm 602 is extended to the working position, the two foldable arms 605a and 605b are simultaneously deployed to the working position. When the seal ring carrier arm 602 contracts, the foldable arms 605a and 605b are moved inwardly from the point p until the fixed arms 604 are aligned and the foldable arms 605a and 605b are folded above or below the fixed arm 604. It can be folded in the f direction. The seal ring carrier shown in FIG. 6C can be made small and simple so that the seal ring carrier arm of the immersion lithography system can be easily moved and stored.

  FIG. 6D shows a seal ring carrier without a fixed arm but with only two foldable arms 605a, 605b. FIG. 6C shows the foldable arms 605a, 605b, each foldable arm being folded from the p point toward the inside f direction, where the p point is located on the side of the seal ring carrier arm 602 and sealed. Connected to ring carrier arm 602. This embodiment has fewer vacuum openings and arms, and has the flexibility to provide different seal ring arms and seal ring carriers. Various seal ring arms and seal ring carriers provided by the present embodiment have functions of sucking, picking up, and moving the seal ring that the seal ring carrier should have.

  The seal ring and seal ring carrier system of this embodiment and the method of using the same surround the immersion liquid with an efficient apparatus in the immersion lithography exposure process. In an operation process of the entire immersion lithography process, a soft seal ring is installed around the edge of the wafer substrate and around the wafer chuck / stage, and the immersion liquid is wrapped in the wafer substrate and the immersion liquid tank at the edge of the wafer substrate. The seal ring of the present embodiment can be installed at the work position or removed from the work position by the seal ring carrier. Therefore, waste and loss of the immersion liquid that controls and limits the immersion liquid can be reduced. Further, when the seal ring of this embodiment is used, the immersion liquid is prevented from coming into contact with the edge of the wafer, and the opportunity for the fine particles to enter the immersion liquid is minimized. Finally, achieving high quality levels and stability through immersion lithography and subsequent process operations prevents the resulting photoresist image and pattern from distorting and failing.

  In the present invention, preferred embodiments have been disclosed as described above. However, these embodiments are not intended to limit the present invention, and any person who is familiar with the technology can use various embodiments within the scope and spirit of the present invention. Changes and modifications can be made. Therefore, the scope of protection of the present invention is based on the contents specified in the claims.

It is sectional drawing which shows the conventional immersion lithography system. It is sectional drawing which shows the conventional immersion lithography system which shows a state when performing process reaction at the edge of a wafer substrate. 1 is a cross-sectional view illustrating an immersion lithography system showing a state when a process reaction is performed at an edge of a wafer substrate according to a first embodiment of the present invention. It is sectional drawing which shows the immersion lithography system which shows a state when performing process reaction by the edge of the wafer substrate by 2nd Embodiment of this invention. 1 is a cross-sectional view illustrating a state when a seal ring carrier according to an embodiment of the present invention is coupled to an immersion lens lithography system. It is a bottom view which shows a state when the seal ring carrier of the immersion lens lithography system by other embodiment of this invention is applied. It is a bottom view which shows a state when the seal ring carrier of the immersion lens lithography system by other embodiment of this invention is applied. It is a bottom view which shows a state when the seal ring carrier of the immersion lens lithography system by other embodiment of this invention is applied. It is a bottom view which shows a state when the seal ring carrier of the immersion lens lithography system by other embodiment of this invention is applied.

Explanation of symbols

  300, 400 Immersion printing portion of lithography system, 302, 402 Wafer chuck / stage, 304, 404, 506, 606 Vacuum channel, 306, 406 Photo resist coated wafer, 308, 408 Immersion liquid, 309, 409 Immersion area , 310, 410 Objective lens element, 312, 412 Liquid supply tank, 314, 414 Liquid recovery tank, 316, 416 Ray, 307, 405, 407 Concave groove, 318, 418, 610 Seal ring, 319 Portion of edge, 500 seal Ring transport assembly, 502, 603 Seal ring carrier, 504, 602, 604, 605, 605a, 605b Arm, 508 Seal ring contact point, 608 Vacuum opening

Claims (10)

A liquid providing an immersion liquid for performing an immersion lithography process on the wafer;
A seal ring that covers a predetermined portion of the edge of the wafer so that the immersion liquid does not leak from the cover portion of the edge of the wafer when the immersion liquid is used in the immersion lithography process;
An immersion lithography system comprising: The immersion lithography system according to claim 1, further comprising a wafer stage on which the wafer is placed. The immersion lithography system according to claim 2, wherein the wafer stage further includes a concave groove in which the wafer is placed so that a plane of the wafer is coplanar with a cover portion of an edge of the wafer. 4. The immersion lithography system according to claim 3, wherein the concave groove has a double step structure in which the seal ring is coplanar with an outer peripheral edge of the concave groove. The immersion lithography system according to claim 2, wherein the wafer is placed on the wafer stage without being placed in the concave groove. The immersion lithography system according to claim 1, wherein the seal ring extends beyond an edge of the wafer. The immersion lithography system according to claim 1, further comprising a seal ring carrier for installing and removing the seal ring on the wafer.   8. The immersion lithography system according to claim 7, wherein the seal ring carrier includes at least one arm selected from a fixed arm and a foldable arm for fixing the seal ring. 9. The immersion lithography system according to claim 8, wherein the seal ring carrier fixes the seal ring by a vacuum suction force. Placing the wafer into a groove in the wafer stage;
Installing a seal ring to cover a predetermined edge portion of the wafer;
Performing an immersion lithography process using an immersion liquid on the wafer;
An immersion lithography method comprising:
An immersion lithography method, wherein the seal ring prevents the immersion liquid from leaking from a cover portion at an edge of the wafer.

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