Potential barrier generating module and lithographic apparatus comprising the same

Abstract

The present application relates to a potential barrier generating module and a lithographic apparatus comprising the same, and particularly relates to a potential barrier generating module and a lithographic apparatus comprising the same, which can minimize the flow of foreign matters in a vacuum system such as a lithographic apparatus.

Description

Technical Field

[0001] This invention relates to a potential barrier generation module and a photolithography apparatus including the same, specifically to a potential barrier generation module and a photolithography apparatus including the same, which can minimize the flow of foreign matter in a vacuum system such as a photolithography apparatus. Background Technology

[0002] In the manufacture of semiconductor devices, a method called photolithography is used to pattern semiconductor wafers. During the photolithography process, a photomask is used as the original pattern and the pattern on the photomask is transferred onto the wafer.

[0003] However, if dust adheres to the photomask, light will be absorbed or reflected by the dust, which will damage the transfer pattern and lead to a decrease in the performance or yield of semiconductor devices.

[0004] Therefore, the above operations are usually carried out in a clean room or vacuum chamber. However, since dust also exists in the clean room or vacuum chamber, a thin film cover is usually used to prevent dust from adhering to the surface of the photomask.

[0005] In this case, the advantage is that dust or foreign matter does not adhere directly to the surface of the photomask, but rather to the thin film of the film mask. And because the focus is aligned with the pattern of the photomask during the photolithography process, the dust or foreign matter on the film mask will not be at the focus and therefore will not be transferred to the pattern.

[0006] Thin film covers need to have good light transmittance, so they are made of extremely thin films. However, thin film covers with thin film structures may break or sag due to external impacts or the stress of the film itself.

[0007] Such damage or sagging can cause image distortion during the transfer process, so the mechanical strength of the film cover must be maintained to keep the film flat without sagging or damage.

[0008] To address this, methods such as applying appropriate tensile stress to the thin film or forming additional reinforcing layers are used to prevent deformation of the thin film mask. However, such methods not only complicate the manufacturing process of the thin film mask, but also cause a decrease in the properties of the thin film mask due to the addition of reinforcing layers. Therefore, there are still many difficulties in the development of thin film masks for extreme ultraviolet lithography.

[0009] Therefore, there is an urgent need to develop a foreign object protection module with a new structure that can replace the function of the aforementioned thin film cover, and a photolithography device including it. Summary of the Invention

[0010] The problem that the invention aims to solve The photolithography apparatus and potential barrier generation module with particle movement blocking function provided in one embodiment of the present invention aim to solve the problems existing in the prior art, and propose the following technical problems for this purpose.

[0011] A photolithography apparatus and potential barrier generation module with particle movement blocking function are provided, which can minimize the inflow of foreign matter to the mask side without the need for traditional physical thin film cover to prevent foreign matter from entering the mask side.

[0012] The technical problems to be solved by the present invention are not limited to those described above. Other unmentioned technical problems will be clearly understood by those skilled in the art through the following description.

[0013] means for solving problems According to the present invention, a potential barrier generation module in a vacuum system is disposed inside a vacuum chamber for blocking particles from moving into a specific area inside the chamber. It includes: an electron beam generator that generates an electron beam along the length of the cylinder by stacking multiple filaments forming a closed curve or by forming a cylinder using a single spring-type filament, thereby forming a columnar potential barrier; and a first collector and a second collector, disposed at intervals from the electron beam generator, and applying a positive voltage.

[0014] Preferably, the electron beam generator is disposed inside the cavity so that the particles can enter the hollow region of the electron beam generator. The particles entering the hollow region become negatively charged as they move along the potential barrier. The negatively charged particles are captured by the first collector or the second collector, or their movement path is changed.

[0015] Preferably, the first collector and the second collector are arranged opposite each other with the center of the electron beam generator as a reference, and the distance between the first collector and the electron beam generator and the distance between the second collector and the electron beam generator are different.

[0016] Preferably, the particles are at least one of dust and particulate matter generated during the process.

[0017] Preferably, the particles are at least one of dust and Sn particles.

[0018] The photolithography apparatus according to the present invention includes: a chamber, the interior of which is maintained in a vacuum state; a light source, disposed inside the chamber and generating light for photolithography; a mask, disposed inside the chamber; a first optical system for transmitting the light generated by the light source to the mask; a second optical system for transmitting the light passing through the mask to a wafer stage; and a first barrier module for forming a columnar first potential barrier to block particles generated by the light source from moving toward the mask.

[0019] The first potential barrier module includes an electron beam generating portion that generates an electron beam in a first direction perpendicular to a filament by stacking a plurality of filaments forming a closed curve or forming a cylinder with a single spring-type filament to form the first electric potential barrier, and first and second collectors disposed apart from the electron beam generating portion to apply a positive voltage.

[0020] Preferably, the electron beam generating portion is disposed inside the chamber to allow particles to enter a hollow region of the electron beam generating portion, the particles entering the hollow region are negatively charged in the process of moving along the first electric potential barrier, and the negatively charged particles are captured by the first or second collector or have their moving paths changed.

[0021] Preferably, the first and second collectors are disposed opposite to each other with the center of the electron beam generating portion as a reference, and the distance between the first collector and the electron beam generating portion is different from the distance between the second collector and the electron beam generating portion.

[0022] Preferably, the first potential barrier module is disposed adjacent to the light source portion to allow particles generated by the light source portion to enter the hollow region of the electron beam generating portion.

[0023] Preferably, a second potential barrier module is further included, which is disposed below the mask to emit an electron beam to form a second electric potential barrier for blocking particles from entering the mask.

[0024] Preferably, the second potential barrier module includes a filament that generates an electron beam, and a housing formed to accommodate the filament therein and formed with a slit in a length direction to emit the electron beam in a direction parallel to the bottom surface of the mask.

[0025] Effects of the Invention The photolithography device and the potential barrier generating module according to an embodiment of the present application can prevent foreign substances flowing inside a chamber from entering a mask side by forming various types of electric potential barriers inside the chamber in a vacuum state.

[0026] Effects of the present application are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 FIG. 1 is a diagram schematically showing a photolithography device according to a first embodiment of the present application having a particle movement blocking function.

[0028] Figure 2 FIG. 2 is a diagram showing a potential barrier generating module according to the first embodiment of the present application. Figure 1A schematic diagram illustrating an example of the formation of a second potential barrier by a second potential barrier module.

[0029] Figure 3 It is used for explanation Figure 1 and Figure 2 A conceptual diagram of the second potential barrier function in the circuit.

[0030] Figure 4 and Figure 5 It is a graph showing the changes in the potential energy and kinetic energy of the particle caused by the second potential barrier.

[0031] Figure 6 This is a schematic diagram illustrating a photolithography apparatus with particle movement blocking function according to a second embodiment of the present invention.

[0032] Figure 7 It is shown Figure 6 A schematic diagram of the first barrier module.

[0033] Figure 8 and Figure 9 This is a schematic diagram showing the electron density of the first potential barrier and the resulting particle movement when the two collectors of the first barrier module are symmetrically arranged.

[0034] Figure 10 and Figure 11 This is a schematic diagram showing the electron density of the first potential barrier and the resulting particle movement when the two collectors of the first barrier module are asymmetrically arranged.

[0035] Figure 12 This is a schematic diagram illustrating a photolithography apparatus with particle movement blocking function according to a third embodiment of the present invention.

[0036] Figure 13 This is a schematic diagram illustrating a photolithography apparatus with particle movement blocking function according to a fourth embodiment of the present invention.

[0037] Figure 14 This is a schematic diagram illustrating a photolithography apparatus with particle movement blocking function according to a fifth embodiment of the present invention. Detailed Implementation

[0038] Preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. Identical or similar constituent elements are given the same reference numerals, which are independent of the drawing numbers, and repeated descriptions thereof will be omitted.

[0039] Furthermore, in describing embodiments of the present invention, detailed descriptions of relevant prior art will be omitted if they are deemed to obscure the essence of the invention. It should also be noted that the accompanying drawings are merely for illustrative purposes and should not be construed as limiting the technical concept of the invention.

[0040] This invention relates to a technical solution that uses a barrier module composed of a non-physical barrier to prevent dust and other particles moving inside a chamber from moving to the other side of the barrier module, i.e., the mask side. In particular, the movement of dust and other particles is blocked by an electric potential barrier, rather than by physical conflict with the barrier module.

[0041] As described above, the barrier module that forms an electric potential barrier can be applied to a lithography apparatus to prevent particles such as dust located in the cavity of the lithography light source from moving to the mask and optical system. This allows extreme ultraviolet (EUV) lithography apparatuses to eliminate the need for thin film covers used to physically prevent foreign matter from entering.

[0042] The following combination Figures 1 to 5 The photolithography apparatus having a particle movement blocking function according to the first embodiment of the present invention will be described.

[0043] like Figure 1 As shown, a photolithography apparatus according to an embodiment of the present invention includes a chamber 100, a light source 200, a mask 300, an optical system 400, a wafer stage 500, and a second barrier module 700.

[0044] The chamber 100 is used to house the various components of the photolithography apparatus and needs to be isolated from the outside to prevent foreign objects from flowing in. Especially for photolithography processes using EUV light sources, in order to minimize the absorption of EUV light in the air, it is preferable to keep the inside of the chamber 100 in a vacuum state.

[0045] The light source unit 200 is used to generate light required for the photolithography process, and preferably, the light source unit 200 of the photolithography apparatus according to an embodiment of the present invention generates EUV light 10 for forming fine patterns.

[0046] EUV light 10 generated from the light source 200 is transmitted through the first optical system 400a to the mask 300 side where a fine circuit pattern is formed. EUV light 10 passing through the mask 300 is transmitted through the second optical system 400b to the wafer placed on the wafer stage 500. At this time, the photosensitive material coated on the wafer reacts under the action of EUV light 10, thereby forming a pattern on the wafer.

[0047] On the other hand, as mentioned above, EUV light 10 has the characteristics of extremely short wavelength and easy absorption. Therefore, the optical system 400, which includes the first optical system 400a and the second optical system 400b, is preferably composed of at least one mirror, rather than the lens used in conventional photolithography apparatus.

[0048] The second barrier module 700 is used to prevent particles 40 such as Sn and dust inside the chamber 100 from entering the mask 300 side. It forms a planar second potential barrier 30 parallel to the bottom surface of the mask 300, which blocks particles from entering the mask 300.

[0049] In other words, the second barrier module 700 is configured to form an electric potential barrier formed by an electron beam under the mask 300, so there is no need to set up a barrier of a thin film cover in the traditional physical way, and foreign objects can be prevented from adhering to the mask 300.

[0050] like Figure 2 and Figure 3 As shown, the barrier module 700 may include a filament 710, a housing 720, an anode 730, and a collector 740.

[0051] The filament 710 is made of tungsten or the like and can be formed into a long strip that extends along the length direction. When an electric current is applied to the filament 710 and the filament 710 is heated to a high temperature, electrons that were originally confined to the surface of the filament 710 escape, thereby forming an electron beam.

[0052] The anode 730 is used to accelerate the electron beam. The housing 720 houses the filament 710 and the anode 730. A slit 721 can be formed along the length direction to allow the electron beam to be emitted outward. Figure 2 As shown.

[0053] like Figure 2 and Figure 3 As shown, the electron beam passing through the slit 721 forms a planar second potential barrier 30 parallel to the bottom surface of the mask 300, thereby preventing the particles 40 located below from entering the direction of the mask 300.

[0054] Specifically, when the neutral Sn particles 40 generated during the generation of EUV light by the light source 200 move toward the mask 300, the neutral Sn particles 40 become negatively charged under the action of the second potential barrier 30, and the negatively charged particles are affected by the electric field around the second potential barrier 30.

[0055] At this time, when the kinetic energy of the particle 40 moving toward the mask 300 is less than its potential energy, the direction of motion of the particle 40 changes, thus preventing it from passing through the second potential barrier 30; while when the kinetic energy of the particle 40 is greater than its potential energy, the particle 40 will pass through the second potential barrier 30, thus being able to enter the mask 300 side.

[0056] That is, the particle velocity, which determines the kinetic energy of particle 40, can be used to determine whether the particle can pass through the second potential barrier 30. The following section combines... Figure 4 and Figure 5 To elaborate further.

[0057] Figure 4 and Figure 5 The graphs show the changes in potential energy (PE) and kinetic energy (KE) of particle 40 when the velocities of particle 40 are 14 cm / s and 20 cm / s, respectively, in the second potential barrier 30 formed under the conditions of 1 kV and 200 mA.

[0058] First, taking the case where particle 40 has a velocity of 14 cm / s as an example, at the boundary of the second potential barrier 30, particle 40 carries a negative charge, therefore... Figure 4 As shown, the potential energy increases while the kinetic energy decreases. Finally, near the center of the second potential barrier 30, the kinetic energy drops to 0 and the direction of motion changes, thereby blocking the particle 40 from entering the mask 300 side through the second potential barrier 30.

[0059] When the velocity of particle 40 is 20 cm / s, it is also negatively charged at the boundary of the second potential barrier 30. Although the kinetic energy decreases while the potential energy increases, the kinetic energy cannot be reduced to 0 at the center of the second potential barrier 30 because the moving particle 40 has a braking distance. Therefore, particle 40 can pass through the second potential barrier 30 and enter the mask 300 side.

[0060] That is, in order to block the movement of particle 40 by the potential barrier, the thickness of the potential barrier also needs to be considered. In particular, for the electron beam passing through the slit 721, the farther away from the emission area, the more the electrons in the electron beam gradually diffuse over time due to the repulsive force between them. Therefore, considering that the electron density distribution in the second potential barrier 30 formed by the electron beam is not uniform in space, it is necessary to increase the thickness of the barrier to expand the range of kinetic energy reduction of particle 40.

[0061] The following combination Figures 6 to 11 The lithography apparatus with particle movement blocking function according to the second embodiment of the present invention will be described, which employs a thicker potential barrier to expand the range of kinetic energy reduction of particle 40.

[0062] like Figure 6As shown, the photolithography apparatus with particle movement blocking function according to the second embodiment of the present invention includes a chamber 100, a light source 200, a mask 300, a first optical system 400a, a second optical system 400b, and a first barrier module 600. The difference between the photolithography apparatus with particle movement blocking function in the first embodiment is that the first barrier module 600 is used instead of the second barrier module 700. Therefore, the first barrier module 600 will be described in detail below.

[0063] The first barrier module 600 is used to block particles 40, such as dust or Sn particles, generated by the light source 200 from moving towards the mask 300 and the optical system 400. Figure 6 and Figure 7 As shown, it is constructed to form a columnar first potential barrier 20.

[0064] The first potential barrier 20 is formed to be thicker along the direction of particle 40's movement, thereby increasing the charge or probability of the particle 40, making it difficult for the particle 40 to pass through the first potential barrier 20.

[0065] In order to form the first potential barrier 20 mentioned above, as Figure 7 As shown, the first barrier module 600 includes an electron beam generator 610, a first collector 620 and a second collector 630, which are arranged opposite each other with reference to the center of the electron beam generator 610.

[0066] The electron beam generating unit 610 forms a cylinder by stacking multiple filaments that form a closed curve, and generates an electron beam along a first direction perpendicular to the filaments, thereby forming a columnar first potential barrier 20.

[0067] The first collector 620 and the second collector 630 are arranged at intervals with the electron beam generator 610. They are structures that apply a positive (+) voltage to capture particles 40 that pass through the first potential barrier 20, or to change the motion path of particles 40 so that they deviate from the target.

[0068] Referring to the above configuration, the configuration and function of the first barrier module 600 will be described in more detail. The electron beam generator 610 is disposed in the chamber 100 so that the particles 40 can enter the hollow region of the electron beam generator 610. It is particularly preferred to be disposed adjacent to the light source 200 so that the particles 40 generated by the light source 200 can directly enter the hollow region of the electron beam generator 610.

[0069] As the particle 40 enters the hollow region and moves along the first potential barrier 20, it becomes negatively charged. The negatively charged particle 40, as... Figure 7 As shown, it is captured by the first collector 620 or the second collector 630, or its movement path is changed so that it does not move toward the target.

[0070] On the other hand, when the first collector 620 and the second collector 630 are respectively arranged at the same distance relative to the center of the electron beam generator 610, such as Figure 8 As shown, the electron density within the first potential barrier 20 is symmetrically distributed. Therefore, although the motion path of particle 40 changes, it can still move as shown in the diagram. Figure 9 Move to the target as shown.

[0071] To prevent this, it is preferable to set the distance between the first collector 620 and the electron beam generator 610 and the distance between the second collector 630 and the electron beam generator 610 to be different from each other.

[0072] Therefore, as Figure 10 As shown, the electron density within the first potential barrier 20 exhibits an asymmetric distribution. At this time, as... Figure 11 As shown, particle 40 deviates from the target direction and moves to the other side. After floating multiple times within the first potential barrier 20, it is eventually captured by the first collector 620 or the second collector 630.

[0073] The following is for reference Figure 12 The lithography apparatus having a particle movement blocking function according to the third embodiment of the present invention will be described.

[0074] The lithography apparatus with particle movement blocking function according to the third embodiment of the present invention is configured to further include a second barrier module 700, compared with the lithography apparatus with particle movement blocking function according to the second embodiment of the present invention.

[0075] That is, by forming two different shapes of potential barriers 20 and 30 inside the photolithography device, it is possible to more reliably prevent foreign matter 40 from flowing into the mask 300 side.

[0076] The following is for reference Figure 13 The lithography apparatus having a particle movement blocking function according to the fourth embodiment of the present invention will be described.

[0077] The photolithography apparatus with particle movement blocking function according to the fourth embodiment of the present invention is the same as the photolithography apparatus with particle movement blocking function according to the second embodiment of the present invention, and is configured to include a cavity 100, a light source 200, a mask 300, a first optical system 400a, a second optical system 400b, and a first barrier module 600. However, the shape of the cavity 100 and the arrangement of each component are different from those of the photolithography apparatus with particle movement blocking function according to the second embodiment of the present invention.

[0078] Specifically, the chamber 100 is configured to include a first region 110, a second region 120 and a channel 130 connecting the first region 110 and the second region 120. The light source 200 is disposed in the second region 120, and the mask 300, the optical system 400 and the wafer stage 500 are disposed in the first region 110.

[0079] That is, by physically separating the first region 110 and the second region 120 and providing a minimum channel 130 through which only light generated by the light source unit 200 can pass, the probability of particles 40 emitted by the light source unit 200 moving to the first region 110 where the other constituent components are provided can be reduced.

[0080] At this time, by setting the first potential barrier module 600 on the channel 130, the first potential barrier 20 is formed along the length direction of the channel 130, thereby more reliably preventing the particles 40 generated by the light source 200 from moving to the first region 110.

[0081] The following is for reference Figure 14 The lithography apparatus having a particle movement blocking function according to the fifth embodiment of the present invention will be described.

[0082] The lithography apparatus with particle movement blocking function according to the fifth embodiment of the present invention is configured to further include a second barrier module 700, compared with the lithography apparatus with particle movement blocking function according to the fourth embodiment of the present invention.

[0083] That is, by forming two different shapes of potential barriers 20 and 30 inside the photolithography device, it is possible to more reliably prevent foreign matter 40 from flowing into the mask 300 side.

[0084] In summary, the photolithography apparatus with particle movement blocking function according to various embodiments of the present invention, when the barrier modules 600 and 700 are configured as described above, blocks the movement of particles 40 such as dust and Sn particles present in the chamber 100 toward the mask 300 or the optical system 400 by means of an electric potential barrier rather than a physical potential barrier, thereby preventing dust from adhering to the mask 300 or the optical system 400 during the photolithography process.

[0085] Therefore, the photolithography apparatus according to the present invention does not require a thin film mask, thus eliminating the complex process for manufacturing the thin film mask. Unlike the thin film mask, the barrier modules 600 and 700 can be used semi-permanently, thereby reducing the cost of photolithography and, in some cases, preventing contamination of the optical system.

[0086] On the other hand, the first barrier module 600 and the second barrier module 700 can be applied not only to semiconductor lithography devices, but also to semiconductor thin film deposition devices such as ALD (Atomic Layer Deposition), PVD (Physical Vapor Deposition), or CVD (Chemical Vapor Deposition).

[0087] The present invention has been described in detail above with reference to preferred embodiments, but the scope of the present invention is not limited to the specific embodiments, but should be interpreted in accordance with the appended claims. Furthermore, those skilled in the art will understand that many modifications and variations can be made without departing from the scope of the present invention.

Claims

1. A potential barrier generation module in a vacuum system, disposed inside a vacuum chamber, for preventing particles from moving into a specific region inside the chamber, characterized in that, The potential barrier generation module within the vacuum system includes: An electron beam generating section generates an electron beam along the length of a cylinder by stacking multiple filaments forming a closed curve or by forming a cylinder using a single spring-type filament, thereby forming a columnar potential barrier; and The first collector and the second collector are spaced apart from the electron beam generator and are subjected to a positive voltage.

2. The potential barrier generation module in the vacuum system according to claim 1, characterized in that, The electron beam generator is disposed inside the cavity so that the particles can enter the hollow region of the electron beam generator. The particles entering the hollow region become negatively charged as they move along the potential barrier. The negatively charged particles are captured by the first collector or the second collector, or their movement path is altered.

3. The potential barrier generation module in the vacuum system according to claim 1, characterized in that, The first collector and the second collector are arranged opposite each other with the center of the electron beam generator as a reference. The distance between the first collector and the electron beam generator is different from the distance between the second collector and the electron beam generator.

4. The potential barrier generation module in the vacuum system according to claim 1, characterized in that, The particles are at least one of dust and particulate matter generated during the process.

5. The potential barrier generation module in the vacuum system according to claim 1, characterized in that, The particles are at least one of dust and Sn particles.

6. A photolithography apparatus, characterized in that, The photolithography apparatus includes: The chamber is kept in a vacuum state. A light source is disposed inside the chamber and generates light for photolithography. A mask is disposed inside the chamber; The first optical system transmits the light generated by the light source to the mask; A second optical system transmits light passing through the mask to the wafer stage; and The first barrier module forms a columnar first potential barrier to block particles generated by the light source from moving toward the mask.

7. The photolithography apparatus according to claim 6, characterized in that, The first barrier module includes: An electron beam generating section generates an electron beam along a first direction perpendicular to the filaments by stacking multiple filaments forming a closed curve or by forming a cylinder using a single spring-type filament, thereby forming the first potential barrier; and The first collector and the second collector are spaced apart from the electron beam generator and are subjected to a positive voltage.

8. The photolithography apparatus according to claim 7, characterized in that, The electron beam generator is disposed within the cavity so that the particles can enter the hollow region of the electron beam generator. Particles entering the hollow region become negatively charged as they move along the first potential barrier. The negatively charged particles are captured by the first collector or the second collector, or their movement path is altered.

9. The photolithography apparatus according to claim 7, characterized in that, The first collector and the second collector are arranged opposite each other with the center of the electron beam generator as a reference. The distance between the first collector and the electron beam generator is different from the distance between the second collector and the electron beam generator.

10. The photolithography apparatus according to claim 7, characterized in that, The first barrier module is disposed adjacent to the light source unit so that the particles generated by the light source unit can enter the hollow region of the electron beam generator unit.

11. The photolithography apparatus according to claim 7, characterized in that, It also includes a second barrier module, which is disposed below the mask and emits an electron beam to form a second potential barrier for blocking particles from entering the mask.

12. The photolithography apparatus according to claim 11, characterized in that, The second barrier module includes: The filament generates an electron beam; and The housing is configured to house the filament internally and has slits formed along its length to emit the electron beam in a direction parallel to the bottom surface of the mask.

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