KR20070048497A - Immersion lithography apparatus - Google Patents

Abstract

The present invention discloses an emulsion lithography apparatus. The disclosed apparatus includes a stage on which a wafer is mounted on an upper surface; A projection lens unit disposed on the stage; An emulsion lens unit disposed in a space between a wafer and the projection lens unit to receive a liquid; And an opening and closing shutter member for sealing the bottom surface of the emulsion lens unit to prevent the liquid from leaking out; and opening and closing means for opening and closing the shutter member from the emulsion lens unit.

Description

Emulsion lithography apparatus

1 schematically depicts a stage of a conventional emulsion lithography apparatus.

2 and 3 are cross-sectional views taken along the line II ′ of FIG. 1.

4 schematically illustrates a stage of an emulsion lithography apparatus of the present invention.

FIG. 5 is a cross-sectional view taken along the line II-II ′ of FIG. 4 for explaining an emulsion lithography apparatus according to an embodiment of the present invention. FIG.

6 is an enlarged partial view of FIG. 5.

FIG. 7 is a cross-sectional view taken along the line II-II ′ of FIG. 4 for explaining an emulsion lithography apparatus according to another embodiment of the present invention. FIG.

TECHNICAL FIELD The present invention relates to a lithographic apparatus, and more particularly, to an emulsion lithography apparatus including an emulsion lens portion for providing a liquid to a space between a wafer and a projection lens portion.

Emulsion exposure techniques seek to improve resolution by filling any liquid between the final projection lens and the wafer and increasing the numerical aperture (hereinafter referred to as NA) of the optical system by the refractive index of the liquid. At this time, the light source propagating from the liquid corresponds to the value of the actual wavelength divided by the refractive index of the medium in the air. When using a 193nm light source (ArF laser), if the water is selected as the medium, the refractive index of water is 1.44. Therefore, the wavelength of the ArF laser through the water decreases from 193nm to 134nm. This typically has the same effect as using a light source with a shorter wavelength, such as an F 2 laser (157 nm) to increase resolution.

Such emulsion exposure techniques can be used in the manufacture of integrated circuits (ICs). In this case, a circuit pattern corresponding to each layer of the integrated circuit IC may be formed. The circuit pattern may be formed by exposing a predetermined portion on a wafer such as silicon coated with a resist film afterwards. Prior to the exposing step, the wafer may be subjected to various processes such as pretreatment, resist coating and soft bake.

1 is a schematic illustration of a stage of a conventional emulsion lithography apparatus. 2 and 3 are cross-sectional views taken along the line II ′ of FIG. 1, and FIG. 3 is a partially enlarged view of FIG. 2. 2 and 3 are views of the projection lens unit and the emulsion lens unit of the conventional emulsion lithography apparatus on the stage of FIG.

As shown in Figs. 1 and 2, a conventional emulsion lithography apparatus includes a projection lens portion 21, an emulsion lens portion 17, and a stage 11.

The emulsion lens unit 17 is disposed in a space between the wafer 13 and the projection lens unit 21 and accommodates the liquid 19 therein.

The stage 11 has a cover plate 12 is disposed on the upper surface. A closing disk 15 and a wafer seating portion 12a are disposed in the cover plate 12. After the wafer exposure process is completed, the closing disk 15 is a place where the emulsion lens unit 17 is moved to seal the bottom surface 18 of the emulsion lens unit 17. The wafer seating portion 12a is a place where the wafer 13 to be exposed is placed.

A process of performing a wafer exposure process using a conventional emulsion lithography apparatus having the above-described configuration will now be described with reference to FIGS. 2 and 3.

As shown in FIG. 2, the wafer 13 on which the exposure process is to be performed is positioned on the wafer seating portion 12a. The wafer 13 may be a wafer on which a resist film is coated. The wafer exposure process is performed by irradiating a beam to the wafer 13 through the projection lens unit 21 and the emulsion lens unit 17.

When the wafer exposure process is completed, as shown in FIG. 3, the emulsion lens unit 17 moves to the closing disk 15. After the movement to the closing disk 15, a process of sealing the bottom surface 18 of the emulsion lens unit 17 is performed. After the movement to the closing disk 15, the bottom surface 18 of the emulsion lens unit 17 and the closing disk 15 may be further aligned and coupled. The wafer on the wafer seat is then replaced with a new one. That is, the wafer on which the exposure process is completed is carried out from the wafer seating portion 12a, and a new wafer on which the exposure process is to be carried is carried in. The sealing of the bottom surface 18 of the emulsion lens unit is to prevent the liquid 17 from flowing into the stage during the replacement of the wafer in the wafer seating portion 12a with a new one.

In the conventional emulsion lithography apparatus, when the wafer exposure process is completed, the emulsion lens unit is moved to the closing disk to seal the bottom surface of the emulsion lens unit. However, it takes a lot of time such as the movement time of the emulsion lens portion to the closing disk, the alignment / bonding time of the bottom surface of the emulsion lens portion and the closing disk and the sealing time. Therefore, there exists a problem that productivity falls.

Therefore, there is a need for a study on an emulsion lithography apparatus that can minimize the time required for sealing the bottom surface of the emulsion lens portion in the closing disk, and aligning and bonding the bottom surface of the emulsion lens portion with the closing disk. .

An object of the present invention is to provide an emulsion lithography apparatus that can simplify the sealing process of the emulsion lens unit.

To solve the above problems, the present invention provides an emulsion lithography apparatus. The apparatus includes a stage on which a wafer is mounted on an upper surface; A projection lens unit disposed on the stage; An emulsion lens unit disposed in a space between the wafer and the projection lens unit to receive a liquid; A shutter member for sealing the bottom surface of the emulsion lens unit to prevent the outflow of the liquid; and an opening and closing means for opening and closing the shutter member from the emulsion lens unit.

Preferably, the emulsion lens unit may be further provided with an air supply device for forming an air curtain along the outer edge of the emulsion lens unit.

Preferably, the stage may be further provided with a vacuum suction device for fixing the wafer on the upper surface.

Preferably, the opening and closing means may be a liner motor.

Preferably, the opening and closing means is an air bearing provided below the shutter member; And a carrier which is moved while being kept parallel to the shutter member surface; and a connecting member which connects the air bearing and the carrier to restrain the air bearing to flow.

Preferably, a coupling protrusion is disposed in the connection member, and a coupling groove corresponding to the coupling protrusion is disposed in the carrier.

Preferably, the air bearing is of vacuum preload type.

Preferably, the emulsion lens unit may further include a liquid inlet duct for supplying liquid to the emulsion lens unit, and a liquid discharge duct for discharging the liquid in the emulsion lens unit.

Further, preferably, the shutter member may be arranged to cover at least the space in which the liquid is contained in the emulsion lens unit.

(Example)

Hereinafter, a cassette loader device of a semiconductor device manufacturing apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

4 is a schematic illustration of a stage of an emulsion lithography apparatus of the present invention. 5 and 6 are cross-sectional views taken along the line II-II ′ of FIG. 4 to explain an emulsion lithography apparatus according to an embodiment of the present invention. 6 is a partially enlarged view of FIG. 5. 5 and 6 are views of the projection lens unit and the emulsion lens unit of the emulsion lithography apparatus according to the embodiment of the present invention on the stage of FIG.

4 to 6, the emulsion lithography apparatus according to the embodiment of the present invention, the stage 31, the projection lens unit 41, the emulsion lens unit 37, the shutter member 40 And an opening and closing part 40.

In the stage 31, as shown in FIG. 4, a cover plate 32 is disposed on an upper surface thereof. The wafer seating portion 31a is disposed in the cover plate 32. The wafer seating portion 31a is a place where the wafer 33 to be subjected to the exposure process is seated. The wafer 33 may be a silicon wafer coated with a resist film thereon. The wafer 33 may be fixed to the stage 31 by a holder (not shown). A vacuum suction device (not shown) for fixing the wafer 33 may be installed on the bottom surface of the wafer seating portion 31a. The wafer seating portion 31a may be disposed in or on the cover plate 32.

 The projection lens part 41 is disposed above the stage 31.

The emulsion lens portion 37 is disposed in the space between the wafer 33 and the projection lens portion 41, and accommodates a liquid 39 having a relatively high refractive index such as, for example, water. Since the liquid 39 has an effect that the radiation of the projection beam through the projection lens portion 41 has a shorter wavelength in the liquid 39 than in air or vacuum, smaller features are exposed during the exposure process. Can be disassembled.

The emulsion lens unit 37 may be provided with a liquid inlet duct 61 and a liquid discharge duct 63 to facilitate the introduction and discharge of the liquid 39. That is, the emulsion lens unit 37 may be filled with the liquid 39 in an appropriate amount by the liquid inlet duct 61 and the liquid outlet duct 63.

The shutter member 50 may seal the bottom surface 38 of the emulsion lens unit 37 to prevent the liquid 39 from leaking out. The shutter member 50 may be arranged to be opened and closed from the bottom surface 38 of the emulsion lens unit 37. The opening and closing operation of the shutter member 50 is made through the opening and closing means. The opening and closing means is for opening and closing the shutter member 40 from the emulsion lens unit 37, as shown in FIG. The motor 51 may be a liner motor. The shutter member 50 may be disposed to cover a space in which at least the liquid 39 of the emulsion lens unit 37 is accommodated. Thus, the liquid 39 is accommodated in the space under the projection lens portion 41 and in the shutter member 50.

The emulsion lens unit 17 may further include an air supply device 65 for forming an air curtain along the periphery of the emulsion lens unit 17. The air curtain serves to prevent the liquid 39 contained in the emulsion lens unit 37 from overflowing. Specifically, since the distance between the emulsion lens unit 37 and the wafer 33 is only a few mm, it is possible to prevent the liquid 39 from leaking even with a small air pressure using the air curtain. .

In the embodiment of the present invention having the above-described configuration, when the wafer exposure process is completed, the bottom surface 38 of the emulsion lens unit 37 is sealed with the shutter member 50 to form the emulsion lens unit 37. Liquid 39 in the < RTI ID = 0.0 >) < / RTI > At this time, the shutter member 50 can be opened and closed, and the opening and closing operation is possible by the opening and closing means using the motor. Therefore, in one embodiment of the present invention, since the sealing operation in the existing closing disk is unnecessary, the shift time of the emulsion lens portion to the closing disk, the alignment and coupling time of the bottom surface of the emulsion lens portion and the closing disk Can shorten. Thereby, the bottom sealing process of an emulsion lens part can be simplified.

FIG. 7 is a cross-sectional view taken along the line II-II ′ of FIG. 4 to explain an emulsion lithography apparatus according to another embodiment of the present invention.

Emulsion lithography apparatus according to another embodiment of the present invention is the same as the embodiment of the present invention, but using an air bearing instead of a motor as an opening and closing means.

As shown in Figure 7, the opening and closing means according to another embodiment of the present invention includes an air bearing 70, the connection member 60 and the carrier 80.

The air bearing 70 is provided below the shutter member 50. The air bearing 70 may take a predetermined distance from the lower surface of the shutter member 50 by forming an air film using air provided at a constant pressure. The air bearing 70 is mainly used in the carbon material so as to evenly distribute and discharge the air provided at a predetermined pressure, the air inlet 75 for sucking the air is disposed on the bottom surface. The air bearing 70 is preferably a vacuum preload type. The air bearing 70 is provided with a coupling portion 71 to which the connection member 60 is coupled. The structure of the coupling portion 71 can be appropriately changed depending on the connection member 60 is applied. In addition, the air bearing 70 may be applied to a variety of known forms as needed.

The connection member 60 serves to move the shutter member 50 in a parallel state by connecting the air bearing 70 and the carrier 80 to restrain the air bearing 70 to flow. The connecting member 60 is coupled to interlock with the air bearing 70 through a screw 90 disposed in the outer region.

The carrier 80 is moved while keeping parallel to the surface of the shutter member 50. A coupling protrusion 61 is disposed in the connection member 60 in an extended form, and a coupling hole 81 corresponding to the coupling protrusion 61 is disposed in the carrier 80. Therefore, the carrier 80 and the connection member 60 are firmly coupled to each other by the coupling protrusion 61.

In another embodiment of the present invention having the above-described configuration, when the wafer exposure process is completed, the bottom surface 38 of the emulsion lens unit 37 is sealed with the shutter member 50 to form the emulsion lens unit 37. Prevents liquid 39 in flowing into the stage 31. At this time, the shutter member 50 can be opened and closed, and the opening and closing operation is possible by the opening and closing means including the air bearing 70. Therefore, in another embodiment of the present invention, since the sealing operation in the existing closing disk is unnecessary, the shift time of the emulsion lens portion to the closing disk, the alignment and coupling time of the bottom surface of the emulsion lens portion and the closing disk are determined. It can be shortened. Thereby, the bottom sealing process of an emulsion lens part can be simplified.

According to the present invention, by sealing the bottom surface of the emulsion lens portion with the shutter member, it is possible to prevent the liquid in the emulsion lens portion from flowing to the stage. Therefore, the present invention can shorten the movement time of the emulsion lens portion to the closing disk, the alignment of the bottom surface of the emulsion lens portion and the closing disk and the coupling time as the existing sealing disk is unnecessary. have. By shortening the time required for the process, there is an advantage to improve the productivity.

Claims (8)

A stage on which a wafer is mounted on an upper surface; A projection lens unit disposed on the stage; An emulsion lens unit disposed in a space between the wafer and the projection lens unit to receive a liquid; An openable shutter member for sealing a bottom surface of the emulsion lens unit to prevent the liquid from leaking out; and And an opening and closing means for opening and closing the shutter member from the emulsion lens unit. The emulsion lithographic apparatus according to claim 1, wherein the emulsion lens unit further comprises an air supply device forming an air curtain along the outer edge of the emulsion lens unit. The emulsion lithography apparatus according to claim 1, wherein the opening and closing means is a liner motor. The method of claim 1, wherein the opening and closing means An air bearing provided below the shutter member; A carrier moved while being kept parallel to the shutter member surface; and And a connecting member connecting the air bearing and the carrier to each other to restrain the air bearing. The emulsion lithography apparatus according to claim 4, wherein a coupling protrusion is disposed on the connection member, and a coupling groove corresponding to the coupling protrusion is disposed in the carrier. 6. An emulsion lithography apparatus according to claim 5, wherein said air bearing is of vacuum preload type. The method of claim 1, wherein the emulsion lens unit, A liquid inlet duct for supplying a liquid to the emulsion lens unit; Emulsion lithography apparatus further comprises a liquid discharge duct for discharging the liquid in the emulsion lens unit. The emulsion lithographic apparatus according to claim 1, wherein the shutter member is disposed so as to cover at least the space in which the liquid is contained in the emulsion lens portion.

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