Lithography system and device for generating laminar flow in lithography system

Abstract

A photolithography system includes a radiation source and a photomask. The radiation source is configured to generate electromagnetic radiation that travels toward the photomask. The photolithography system also includes an incident channel located between the radiation source and the photomask for passing the electromagnetic radiation. There is a first nozzle and a second nozzle, the first nozzle is configured to generate a first particle shield between the photomask and an outlet port of the incident channel and the second nozzle is configured to generate a second particle shield within the incident channel.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a photolithography system and a device for generating a laminar flow in the photolithography system. Background Art

[0002] Semiconductor manufacturing includes various processes such as photolithography, etching, and diffusion. Functional density has been increased by reducing the geometric size of the components of the integrated chip. This scaling down process improves production efficiency and reduces the associated manufacturing costs. Removing debris and byproducts from equipment, photomasks, and wafers helps improve production yield.

[0003] In some methods, a cleaning solvent such as deionized water is sprayed on the surface to remove particles accumulated on the surface. In some methods, a solid shield is installed on the wafer transport / storage pad during the manufacturing process. In some methods, loading and unloading of wafers is performed automatically by sealed input / output tools such as standard mechanical interface (SMIF) equipment. In some methods, the clothing of process operators is cleaned to reduce contamination caused by particles introduced into the manufacturing environment. Summary of the invention

[0004] Some embodiments of the present disclosure provide a lithography system, comprising: a radiation source configured to generate electromagnetic radiation; a photomask; an incident channel located between the radiation source and the photomask, for causing the electromagnetic radiation to travel toward the photomask; a first nozzle configured to generate a first particle shielding body between the photomask and an outlet port of the incident channel; and a second nozzle configured to generate a second particle shielding body within the incident channel.

[0005] In addition, other embodiments of the present disclosure provide a lithography system, comprising: an extreme ultraviolet radiation source configured to generate extreme ultraviolet radiation; an extreme ultraviolet mask; a first type of nozzle, close to the extreme ultraviolet mask; and a plurality of second type of nozzles, close to the extreme ultraviolet radiation source, the second type of nozzles being different from the first type of nozzles, wherein the first type of nozzles and the second type of nozzles are configured to generate a particle shield in the propagation path of the extreme ultraviolet radiation.

[0006] In addition, other embodiments of the present disclosure provide an apparatus for generating laminar flow in a lithography system, comprising: a pump; and a nozzle, the nozzle comprising a side wall and a diverter, the side wall defining a gas connecting channel having an input port and an output port, the diverter dividing the gas connecting channel into two sub-channels, wherein the diverter protrudes out of the output port. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] By reading the following detailed description in conjunction with the accompanying drawings, various aspects of the present disclosure will be best understood. It should be noted that, according to standard practice in the industry, various features are not drawn to scale. In fact, the size of the various features may be arbitrarily increased or reduced for clarity of discussion.

[0008] Figure 1A is a top view of an apparatus for producing a particle shield according to one or more embodiments.

[0009] Figure 1B and Figure 1B' The apparatus for producing a particle shield according to one or more embodiments is as follows Figure 1A A cross-sectional view taken along line BB'.

[0010] Figure 1C is a top view of an apparatus for producing a plurality of particle shields according to one or more embodiments.

[0011] Figure 1D is a top view of an apparatus for producing a particle shield according to one or more embodiments.

[0012] Figure 2A is a top view of an apparatus for producing a particle shield according to one or more embodiments.

[0013] Figure 2B The apparatus for producing a particle shield according to one or more embodiments is as follows Figure 2A A cross-sectional view taken along line BB'.

[0014] Figure 2C is a cross-sectional view of an apparatus for producing a particle shield according to one or more embodiments.

[0015] Figure 3 is a schematic cross-sectional view of an apparatus for producing a particle shield according to one or more embodiments.

[0016] Figure 4 is a schematic diagram of a lithography system according to one or more embodiments.

[0017] Figure 5 is a schematic diagram of a lithography system according to one or more embodiments.

[0018] Figure 6 is a schematic cross-sectional view of a nozzle for producing a particle shield according to one or more embodiments.

[0019] Fig. 7A and Figure 7B is a schematic cross-sectional view of a suction nozzle for producing a particle shield according to various embodiments.

[0020] Figure 8 is a schematic cross-sectional view of another nozzle for producing a particle shield according to one or more embodiments.

[0021] Fig.9A and Fig. 9B is a schematic cross-sectional view of another suction nozzle for producing a particle shield according to various embodiments.

[0022] Fig. 10A , Fig. 10B , Fig. 10C and Fig. 10D is a schematic cross-sectional view of a nozzle according to various embodiments.

[0023] Fig.11A , Fig. 11B and Fig. 11C is a perspective view of an apparatus for producing a particle shield according to one or more embodiments.

[0024] Fig.12 is a schematic diagram of an extreme ultraviolet (EUV) lithography system according to one or more embodiments.

[0025] Fig.13 is a schematic cross-sectional view of a parallel plate nozzle for producing a particle shield according to one embodiment.

[0026] Fig.14 is a schematic cross-sectional view of another nozzle for producing a particle shield according to one embodiment.

[0027] Fig.15 is a schematic diagram of an extreme ultraviolet lithography system according to one or more embodiments.

[0028] Fig.16 is a graph illustrating the effect of applying different numbers of particle shields against incident metal particles according to one or more embodiments. DETAILED DESCRIPTION

[0029] The following disclosure provides many different embodiments or examples for implementing the different features of the provided subject matter. The following describes specific examples of parts, values, operations, materials, arrangements, or the like to simplify the present disclosure. Of course, these are only examples and are not intended to be limiting. Other parts, values, operations, materials, arrangements, or the like are also encompassed. For example, forming a first feature on or on a second feature in the following description may include an embodiment in which the first feature and the second feature are formed as direct contacts, and may also include an embodiment in which additional features may be formed between the first feature and the second feature so that the first feature and the second feature may not be in direct contact. In addition, the present disclosure may reuse reference numbers and / or letters in various examples. This repetition is for the purpose of simplicity and clarity, rather than the relationship between the various embodiments and / or configurations discussed by itself.

[0030] Furthermore, for ease of description, spatially relative terms such as "beneath," "below," "lower," "above," "upper," etc. may be used herein to describe the relationship of one element or feature to another (other) element or feature as shown in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein should be interpreted accordingly.

[0031] Photolithography is a process for transferring a pattern on a photomask to a substrate or a layer on a substrate. The photomask, frame, and pellicle are collectively referred to as a mask system. The frame holds the photomask and the pellicle includes a transparent film located on the frame. The pellicle protects the photomask and helps prevent particles from entering the focus of the light passing through the photomask. Particles are introduced into the photolithography equipment by removing the photomask from the chuck or removing material from the substrate or a layer on the substrate, or by other contaminants present in the manufacturing environment. Particles in the optical path of the light passing through the photomask disperse the light incident on the particles. Such light dispersion reduces the quality of the pattern imparted by the light beam passing through the photomask. Particles also adhere to the surface of the substrate (or layer of the substrate), the surface of the manufacturing equipment, or the surface of the measurement system. Particles on the substrate or on the layer of the substrate potentially block the light from the photomask from being incident on the substrate (or layer of the substrate) and prevent the accurate transfer of the pattern of the photomask. Particles on the surfaces of manufacturing equipment or measurement systems also potentially scatter light contacting those elements and reduce the accuracy of pattern transfer. In at least one embodiment, a shielding device helps prevent particles from adhering to the surface, or removes particles from the surface or optical path during the manufacturing process and, in turn, improves manufacturing yield.

[0032] Figure 1A 1 is a top view of an apparatus 100 for generating a particle shield 130 according to one or more embodiments, the apparatus 100 is also referred to as a particle shield generator. The apparatus 100 includes a first component 110 and a second component 120. The apparatus 100 is configured to generate a particle shield 130 between the first component 110 and the second component 120. To help prevent particles or contaminants from falling on or contacting the surface 140S of the object 140, in some embodiments, the particle shield 130 (indicated by an arrow symbol) overlaps with the surface 140S and is physically separated from the surface 140S. In some embodiments, the particle shield 130 is not visible to the human eye. In some embodiments, the object 140 is a substrate, a photomask, a wafer, or an inner wall of a carrier (e.g., a wafer carrier or a photomask carrier). In some embodiments, the substrate or wafer includes one or more layers. In some embodiments, the combination of a substrate (e.g., a silicon wafer or a glass substrate) and additional layers located on the substrate is still referred to as a substrate during the manufacturing process. In some embodiments, the object 140 is a selected component in a manufacturing system, such as a reticle edge masking assembly (REMA), an illumination aperture, or a lens in a scanner system. In some embodiments, the surface 140S has a rectangular shape defined by a length L0 and a width W0, which correspond to the length L1 and the distance D1 of the particle shield 130. To substantially cover the surface 140S, the length L1 is equal to or longer than the length L0, and the distance D1 is equal to or longer than the width W0. Therefore, the area of ​​the particle shield 130 is equal to or greater than the area of ​​the surface 140S. In some embodiments, the length L1 and the distance D1 are in a range of about 127 millimeters (mm) to about 305 mm. In some cases, a longer length L1 or a longer distance D1 and a shorter length L1 or a shorter distance D1 may increase the difficulty of controlling the particle shield 130.

[0033] In some embodiments, both the first component 110 and the second component 120 are fixed relative to the surface 140S. In some embodiments, at least one of the first component 110 or the second component 120 is movable relative to the surface 140S. In at least one embodiment, the movement is along a direction X parallel to the distance D1. In at least one embodiment, the movement is along a direction Y parallel to the length L1. Direction X and direction Y are parallel to the surface 140S. The longitudinal axis of the first component 110 (e.g., along the Y direction) is parallel to the longitudinal axis of the second component 120 (e.g., along the Y direction). In some embodiments, the longitudinal axis of the first component 110 and the longitudinal axis of the second component 120 are parallel to the surface 140S. In some embodiments, at least one of the first component 110 or the second component 120 is movable along a direction Z orthogonal to the surface 140S.

[0034] In some embodiments, the first component 110 and the second component 120 are physically coupled to each other directly or through other hardware (not shown). In some embodiments, the first component 110 and the second component 120 are physically separated from each other. The device 100 includes the first component 110 and the second component 120 located on opposite sides of the object 140; however, in some embodiments, the first component 110 and the second component 120 have different arrangements relative to the object 140 to protect other surfaces. In some embodiments, the device 100 also includes a third component 115 and a fourth component 125. In some embodiments, the third component 115 and the fourth component 125 are positioned transversely to the first component 110 and the second component 120. In some embodiments, the device 100 is operable to form an additional particle shield between the third component 115 and the fourth component 125. In some embodiments, the third component 115 and the fourth component 125 provide a redundant device in case of failure of the first component 110 or the second component 120, in such a manner that the additional particle shield is positioned substantially coplanar with the particle shield 130. In some embodiments, the third and fourth components 115 and 125 provide an additional particle shield in this manner to enhance protection; the additional particle shield is located above or below the particle shield 130. In some embodiments, the first and second components 110 and 120 can be used to form the particle shield 130 at the same time as the third and fourth components 115 and 125 form the additional particle shield. In some embodiments, the first and second components 110 and 120 can be used to form the particle shield 130 before or after the third and fourth components 115 and 125 form the additional particle shield.

[0035] In some embodiments, at least one of the axis of the first component 110 or the axis of the second component 120 is relative to the surface 140S (eg, Figure 1B'The tilt angle θ is in a range from greater than 0 degrees to about 45 degrees, and the angle θ can be adjusted based on the area of ​​the surface 140S and the working environment.

[0036] Figure 1B The apparatus 100 for producing a particle shield 130 according to one or more embodiments is as follows Figure 1A . In some embodiments, the first component 110 includes at least one gas injector 112. In at least one embodiment, the gas injector 112 is referred to as an air knife or an air jet. In some embodiments, the particle shield 130 is blown out from the gas injector 112 into the space by the Coanda effect, which is the adhesion of a fluid when it is close to a surface, resulting in asymmetric expansion. In some embodiments, the particle shield 130 is formed by compressing or pumping gas from the gas injector 112. In some embodiments, the gas supply source is connected to the gas injector 112 by a connecting pipe (not shown in the figure). In some embodiments, the particle shield is generated by the pressure difference between the first component 110 and the second component 120. The gas injector 112 injects the particle shield 130 (the protective gas flow flowing into the space between the first component 110 and the second component 120) and provides fluid dynamic control of the particle shield 130. In some embodiments, the particle shield 130 is a gas curtain comprising an inert gas such as argon or helium. In some embodiments, the particle shield 130 comprises ambient air, nitrogen, hydrogen, or a combination thereof.

[0037] In some embodiments, the second component 120 includes at least one gas extractor 122. In at least one case, the gas extractor 122 is aligned at the same level as the gas injector 112 in a direction Z that is parallel to the normal of the surface 140S. In some embodiments, the gas extractor 122 is located above or below the gas injector 112 in the direction Z. In at least one embodiment, the gas extractor 122 extracts particles output by the gas injector 112 and other particles passing between the gas injector 112 and the gas extractor 122. In some embodiments, the gas extractor 122 includes a vacuum. The gas injector 112 and the gas extractor 122 work together to provide a sufficient air pressure gradient for the particle shield 130 even in a vacuum environment, thereby helping to prevent particles or contaminants from reaching the surface 140S. In some embodiments, during operation, the particle shield 130 is circulated through the gas injector 112 and the gas extractor 122, for example, by circulating gas from the gas extractor 122 back to the gas injector 112 after filtering any particles therein. In some embodiments, the second component 120 optionally includes an air receiver instead of the gas extractor 122 to passively receive the particle shield 130 formed by the gas from the gas injector 112 .

[0038] In some embodiments, the particle shield 130 is separated from the surface 140S by a spacing S1 ranging from about 0.5 mm to about 30 centimeters (cm). In some cases, a larger spacing S1 may reduce the functionality of the particle shield 130 because the increased space between the particle shield 130 and the surface 140S will allow particles to enter a greater distance in the spacing S1 from the direction X or the direction Y. In some cases, a shorter spacing S1 may increase the risk of contact between the particle shield 130 and the surface 140S.

[0039] In some embodiments, the particle shield 130 has a thickness T1 above the surface 140S. The thickness T1 is in a range of about 1 mm to about 90 mm. In some cases, due to the low density of the particle shield 130, a thicker thickness T1 may reduce the functionality of the particle shield 130. In some embodiments, the thickness T1 is substantially uniformly distributed between the first component 110 and the second component 120. Such a particle shield 130 is a type of laminar flow and will be combined with Figures 6 to 8 The mechanism for forming the laminar flow is further discussed. In some embodiments, the thickness T1 increases from the first component 110 to the second component 120 .

[0040] In some embodiments, the first component 110 includes two or more air injectors 112 positioned side by side (i.e., along direction Y) or one above the other (i.e., along direction Z). In some embodiments, when positioned side by side, the outlet of each gas injector 112 is formed in a nozzle shape. In some embodiments, when positioned one above the other, the outlet of each gas injector 112 is formed in a slot shape extending in direction Y. In some embodiments, to provide additional gas extraction, the second component 120 includes two or more gas extractors 122.

[0041] Figure 1C 1 is a top view of an apparatus 100' for producing a plurality of particle shields 130a', 130b', 130c', 130d', and 130e' according to one or more embodiments. The apparatus 100' is similar to the apparatus 100, and like elements have like reference numbers with a "'" symbol. The first component 110' corresponding to the first component 110 of another embodiment includes a plurality of gas injectors 112a', 112b', 112c', 112d', and 112e', and the second component 120' corresponding to the second component 120 of another embodiment includes a gas extractor 122'. The plurality of particle shields 130a' to 130e' are produced between the gas injectors 112a' to 112e' and the gas extractor 122'. In some embodiments, the gas extractor 122' includes a plurality of gas extractors, each of which corresponds to one of the gas injectors 112a' to 112e'. Figure 1B Similar to the device 100 in FIG. 1 , the combined area of ​​the particle shields 130a′ to 130e′ is equal to or greater than the surface 140S′. In some embodiments, each of the particle shields 130a′ to 130e′ contains the same gas. In some embodiments, at least one of the particle shields 130a′ to 130e′ contains a gas different from the gas of at least another of the particle shields 130a′ to 130e′.

[0042] Figure 1Dis a top view of an apparatus 100" for creating a particle shield 130" according to one or more embodiments. Apparatus 100" is similar to apparatus 100, and like elements have like reference numerals with """ symbols. Apparatus 100" includes a first component 110" and a second component 120". The first component 110" and the second component 120" have a curved shape. A particle shield 130" is created between the first component 110" and the second component 120". The particle shield 130" helps prevent contaminants from reaching a surface 140S" of an object 140". In some embodiments, the surface 140S" has a circular shape defined by a diameter W0", and the particle shield 130" has an oval shape covering the surface 140S" and the oval shape has a major axis and a minor axis of different lengths. In one example, the minor axis is along a direction pointing from the first component 110" to the second component 120". The length L1" and the distance D1" are therefore determined based on the surface 140S". To substantially cover surface 140S", each of length L1" and distance D1" is equal to or longer than diameter W0". For example, for a 300-mm (12 inch) wafer, each of length L1" and distance D1" is equal to or greater than 300 mm (12 inches).

[0043] Figure 2A 2 is a top view of an apparatus 200 for generating a particle shield 230, also referred to as a particle shield generator, according to one or more embodiments. The apparatus 200 is similar to the apparatus 100, and like elements have like reference numbers increased by 100. The apparatus 200 includes a first component 210 and a second component 220. The apparatus 200 is configured to generate a particle shield 230 (best seen in FIG. 1 ) between the first component 210 and the second component 220. Figure 2B In at least one embodiment, the particle shield 230 is a magnetic field. In some embodiments, the first component 210 and / or the second component 220 have an electromagnet or a permanent magnet. In some embodiments, the parameters in the positioning, spacing, and strength design of the particle shield 230 configuration are computationally optimized based on electromagnetism and the size of the surface area to be protected from particle contamination. In some embodiments, the length L2 is in the range of about 127 mm to about 305 mm. In some embodiments, the magnetic field strength is in the range of about 0.5 Tesla to 1.4 Tesla or greater. In some cases, a smaller magnetic field strength reduces the protective function of the particle shield 230. In some embodiments, the particle shield 230 applies a velocity dependent force, such as a Lorentz force caused by the interaction between the magnetic field and at least one moving charged particle.

[0044] The first force 250 and the second force 252 are in opposite directions along the direction Y. Under the action of the electromagnetic field Lorentz force, the charged particles or contaminants will be driven away from the area of ​​the surface 240S of the object 240 along the direction Y when approaching the particle shield 230. The Lorentz force is perpendicular to both the velocity of the charged particles and the magnetic field (i.e., the particle shield 230), and the direction is given by the right hand rule. The force is given by multiplying the charge by the vector product of the velocity and the magnetic field. Positively charged particles are subject to a force in a first direction and negatively charged particles are subject to a force in a second direction opposite to the first direction. For example, when negatively charged particles contact the particle shield 230, the negatively charged particles are driven by the second force 252. In some embodiments, the length L2 of the first component 210 is equal to or greater than the length L0 of the surface 240S. The magnitude of the first force 250 or the second force 252 is large enough to push the charged particles away from the surface 240S.

[0045] Figure 2B 2 is a cross-sectional view of an apparatus 200 for generating a particle shield 230 according to one or more embodiments. In some embodiments, the particle shield 230 includes another energy gradient force, such as a thermal gradient driving force generated by a temperature difference. In at least one case, the first component 210 has a higher temperature than the second component 220, thereby causing the movement of particles from the first component 210 to the second component 220. In some embodiments, the first component 210 includes a North Pole magnet 212 and the second component 220 includes a South Pole magnet 222. The particle shield 230 is a magnetic field represented by an arrow symbol. In some embodiments, the surface 240S is proportional to the magnetic field along the direction Z. Figure 2B Shown closer to magnet 212 and magnet 222 , such that object 240 is enclosed within particle shield 230 .

[0046] Figure 2C2 is a cross-sectional view of an apparatus 200' for generating one or more particle shields according to one or more embodiments. In some embodiments, a combination of energy gradient forces and velocity-dependent forces are used to enhance particle protection. For example, a first component 210 including an N-pole magnet 212 is located above a first component 110 including a gas injector 112; a second component 220 including an S-pole magnet 222 is located above the second component 120. In some embodiments, the first component 110 and the second component 120 are located above the first component 210 and the second component 220. Alternatively, the first component 110 and the second component 120 are positioned transversely to the first component 210 and the second component 220, similar to the third component 115 and the fourth component 125 in the apparatus 100. Compared to the apparatus 100, in some embodiments, the particle shield 130 is coplanar with the particle shield 230 because there is no interaction between the gas and the magnetic field.

[0047] In some embodiments, both the energy gradient force and the velocity-dependent force are generated by the same component. For example, the first component 210 and the second component 220 are used to generate an air curtain and a magnetic field. One of ordinary skill in the art will appreciate that the first component 210 or the second component is not limited to an air curtain or a magnetic field. In at least one embodiment, at least one of the first component 210 and the second component 220 is used to generate an optical laser to burn particles. In some embodiments, the apparatus 200' includes more than two particle shields, such as a combination of an air curtain, a magnetic field, and a thermal gradient driving force.

[0048] Figure 33 is an enlarged schematic diagram of an apparatus 300 for generating a particle shield 330, also referred to as a particle shield generator, according to one or more embodiments. Apparatus 300 is similar to apparatus 100, and like elements have like reference numbers increased by 200. Apparatus 300 includes a first component 310. In some embodiments, first component 310 is a gas injector 312. Gas injector 312 generates a particle shield 330, and particle shield 330 includes an upper surface 330U and a lower surface 330L. A thickness T3 of particle shield 330 is defined by a distance between upper surface 330U and lower surface 330L. In various embodiments, particle shield 330 provides a gas curtain along width W0 in direction X to help block particles, and thickness T3 is modified by several parameters, such as gas density, molecular weight, and velocity of the gas fluid. In some embodiments, thickness T3 is in a range of about 1 mm to about 90 mm. For example, at the end of the particle shield 330 extending to 152 mm (6 inches), the thickness T3 ranges from 25.4 mm to about 38.1 mm. In some cases, due to the low density of the particle shield 330, a thicker thickness T3 may reduce the functionality of the particle shield 330. In some embodiments, the upper surface 330U is substantially inclined upward and has an angle between about 5 degrees and about 11 degrees above the direction X and the lower surface 330L is parallel to the surface 340S. Incoming particles are pushed away from the surface 340S. In some cases, due to the large gradient, the particle shield 330 may contact the edge of the surface 340S. To help prevent the lower surface 330L of the particle shield 330 from contacting the surface 340S, the component 310 is designed to maintain a spacing S3 between the lower surface 330L and the surface 340S that is greater than the maximum value of the thickness T3.

[0049] Compared to apparatus 100, apparatus 300 does not include a second component. The second component is omitted from apparatus 300 because the force of the gas ejected from first component 312 is strong enough to block particles without the assistance of the second component. In some embodiments, the device containing apparatus 300 and surface 340S has an opening located opposite first component 312 to allow particles to be discharged from the device. In some embodiments, apparatus 300 includes a second component. In some embodiments, first component 312 is as in apparatus 100'( Figure 1C ) is divided into multiple first parts.

[0050] Figure 44 is a schematic diagram of a lithography system 400 according to one or more embodiments. The lithography system 400 includes an apparatus for generating a particle shield, which is similar to the apparatus 100 (or the apparatus 100', the apparatus 100", the apparatus 200, the apparatus 200' and the apparatus 300), and the last two numerals of the same elements are the same. The lithography system 400 includes a photomask 440, a slit 442, a radiation source 444, a plurality of reflectors or mirrors 446 and 446', and a set of openings 448 and 448'. An optical energy beam 450 is generated by the radiation source 444, and the optical energy beam 450 is directed along the reflectors 446, 446' and 446'. The optical path of aperture 448 and slit 442 propagates to photomask 440. Optical energy 450 is reflected by photomask 440 and propagates through slit 442, aperture 448' and reflector 446'. Reflector 446' reduces the image from photomask 440 used to form the image on the wafer. In some embodiments, the distance between photomask 440 and slit 442 is in the range of about 10 mm to about 100 mm. Apparatus 400 includes a reflective imaging system. In some embodiments, apparatus 400 includes a catadioptric imaging system.

[0051] The photolithography system 400 further includes a first component 410, a second component 420, a third component 410', and a fourth component 420'. A first particle shield 430 is located between the first component 410 and the second component 420. A second particle shield 432 is located between the third component 410' and the fourth component 420'. The first component 410 and the second component 420 are located between the photomask 440 and the slit 442. The third component 410' and the fourth component 420' are located between the slit 442 and the openings 448 and 448'. Both the first particle shield 430 and the second particle shield 432 help prevent particles or contaminants from adhering to or falling on the photomask 440 and / or the slit 442. In some embodiments, both the first particle shield 430 and the second particle shield 432 include a gas flow. For example, the first particle shield 430 and the second particle shield 432 include hydrogen, ambient air, helium, nitrogen, or an inert gas. In some embodiments, the first particle shield 430 and the second particle shield 432 comprise different gases. In some embodiments, the size of the first particle shield 430 and the second particle shield 432 ranges from 4 inches by 4 inches to 6 inches by 6 inches. In some embodiments, the size of the first particle shield 430 and the second particle shield 432 is greater than 6 inches by 6 inches. In some cases, the larger size of the first particle shield 430 increases the size of the photomask container. In some cases, the larger size of the first particle shield 430 cannot be installed in the photolithography system 400. The smaller size makes the photomask 440 insufficiently covered to prevent particles from contacting the photomask 440. In some embodiments, the thickness of the first particle shield 430 and the second particle shield 432 ranges from about 1 mm to about 35 mm. In some embodiments, the first particle shield 430 and the second particle shield 432 comprise a combination of energy gradient forces and velocity-related forces. For example, the first particle shield 430 comprises a gas and the second particle shield 432 comprises an electromagnetic Lorentz force. In various embodiments, one or more sets of components for creating a particle shield are positioned close to the radiation source 444, the reflectors 446, 446', the openings 448, 448', or the surface of any of the wafers, depending on the cleanliness requirements. In some embodiments, the lithography system 400 includes the apparatus 100, the apparatus 100', the apparatus 100", the apparatus 200, the apparatus 200', the apparatus 300, or a combination thereof.

[0052] In some embodiments, the photolithography system 400 is an extreme ultraviolet (EUV) exposure scanner and the slit 442 is a mask edge masking component. In some cases, the photomask 440 is also referred to as a mask or a reticle. In some embodiments, the radiation source 444 is formed by plasma when a laser irradiates a gas (e.g., xenon gas is ejected at a speed faster than the speed of sound in air (approximately 340 m / s)). For example, the radiation source 444 provides extreme ultraviolet radiation having a wavelength of approximately 13.5 nm. In some embodiments, when the first particle shield 430 and the second particle shield 432 include a gas, the transmission loss between the optical energy beam 450 and the optical energy beam 450' is in the range of about 0.011% to about 0.022%. In some embodiments, the gas has a low absorption rate for the optical energy 450. Larger transmission losses reduce the exposure of the layout pattern on the wafer. In some embodiments, the photolithography system 400 is X-ray lithography, ion beam projection lithography, or electron beam projection lithography.

[0053] Figure 5 is a schematic diagram of a lithography system 500 according to one or more embodiments. The lithography system 500 includes an apparatus similar to the apparatus 100 (or apparatus 100', apparatus 100", apparatus 200, apparatus 200', and apparatus 300) for producing a particle shield, and like elements with like reference numbers have the same last two numerals. The lithography system 500 includes a photomask 540, a lens 542, a radiation source 544, an imaging module 546, and a fluid 560. The first component 510, the second component 520, and the first particle shield 530 are located between the radiation source 544 and the lens 542. The third component 510', the fourth component 520', and the second particle shield 530' are located between the lens 542 and the photomask 540. The fifth component 510", the sixth component 520", and the third particle shield 530" are located between the photomask 540 and the imaging module 546. The radiation source 544 emits an optical energy beam 550 that passes through the first particle shield 530 and the lens 542. The optical energy beam 550' then passes through the second particle shield 530' and the photomask 540. The optical energy beam 550" then passes through the third particle shield 530" and the imaging module 546. The fluid 560 fills at least the space between the imaging module 546 and the wafer 570. In some embodiments, each of the first particle shield 530, the second particle shield 530', and the third particle shield 530" independently includes a gas fluid or a velocity-related force. In some embodiments, the lithography system 500 includes the apparatus 100, the apparatus 100', the apparatus 100", the apparatus 200, the apparatus 200', the apparatus 300, or a combination thereof.

[0054] In some embodiments, the lithography system 500 is an immersion lithography system. In some embodiments, similar to the lithography system 400, each of the first particle shield 530, the second particle shield 530', and the third particle shield 530" includes an energy gradient force, a velocity-dependent force, or a combination thereof. In at least one embodiment, when the first particle shield 530, the second particle shield 530', and the third particle shield 530" are composed of a gas fluid, the photon transmission loss between the optical energy beam 550 and the optical energy beam 550' is in a range of about 0.011% to about 0.033%. In various embodiments, one or more sets of components are positioned on selected surfaces in the lithography system 500 depending on the cleanliness requirements.

[0055] In some embodiments, device 100, device 100', device 100", device 200, device 200', device 300 is arranged over a selected surface during other manufacturing process lines (e.g., a standard mechanical interface (SMIF) pod station, or a spectral critical dimension tool, a photoresist spinner, or a wet spray etcher).

[0056] Figure 6 An exemplary first component 110 for producing a particle shield 130 is provided along Figure 1A 1. A cross-sectional view taken along line BB' in FIG. 1. In the illustrated embodiment, the first component 110 receives a gas or fluid supply from a supply port 602 coupled to a supply source 604 and ejects the particle shield 130 from a main outlet 606. The first component 110 may also be referred to as a nozzle 110. In some embodiments, the supply source 604 is a gas pump that provides ambient air, nitrogen, hydrogen, an inert gas, or a combination thereof. The gas pump 604 uses a nozzle denoted by F pump The driving force of the gas stream is pumped into the supply port 602. The gas stream is then ejected from the main outlet 606 to form a particle shield 130. The particle shield 130 formed by gas molecules may also be referred to as a non-solid materialistic particle air shield. In some embodiments, the particle shield 130 is a laminar flow. Laminar flow is referred to as a fluid or gas that flows in parallel layers with substantially no interruptions (e.g., eddies or turbulence) between the layers. In the illustrated embodiment, the particle shield 130 is a laminar jet flow that has a strong momentum when leaving the main outlet 606 and can travel a long distance into the surrounding medium without substantially dissipating.

[0057] Nozzle 110 has splitter 608 between two side covers 609-1 and 609-2. Splitter 608 and two side covers 609-1 and 609-2 form upper sub-channel 610-1 and lower sub-channel 610-2 respectively, and lower sub-channel 610-1 and lower sub-channel 610-2 are collectively referred to as channel 610. The gas flow from supply port 602 enters two sub-channels (sub-channel 610-1 and sub-channel 610-2) after being divided into two equal streams. In certain embodiments, splitter 608 can divide the gas flow into three or more sub-channels. In the embodiment shown, splitter 608 has a teardrop shape, and the teardrop shape has a wider end 612 facing supply port 602 and a narrower end 614 facing main outlet 606. The wider end 612 is connected to the narrower end 614 by a smooth surface 616. Smooth surface 616 also provides an inner side wall for channel 610. The smooth surface 616 may have a curved shape. In the area near the narrower end 614, a portion of the smooth surface 616 may be a flat surface. In one example, the wider end 612 has a rounded end 618. In another example, the end 618 is pointed. The shape of the end 618 depends on the specific needs of fluid dynamic control in various applications. Similarly, the narrower end 614 has an end 620, which may be rounded or pointed. In a specific embodiment, the wider end 612 has a rounded end 618, which prevents vortices from occurring during gas flow diversion, and the narrower end 614 has a pointed end 620, which is conducive to the occurrence of gas flow in the narrow area near the opening of the main outlet 606.

[0058] Along the air flow path in the sub-channel 610-1, the nozzle 110 also includes two side splitters 630-1 and a side splitter 630-2. The side splitter 630-1 forms a side channel 640-1 together with the side cover 609-1 and forms an internal channel 650-1 together with the splitter 608. The gas flow from the sub-channel 610-1 is further split into (e.g., equally divided into) two streams and then enters the side channel 640-1 and the internal channel 650-1. The side splitter 630-2 forms a side channel 640-2 together with the side cover 609-2 and forms an internal channel 650-2 together with the splitter 608. The gas flow from the sub-channel 610-2 is further split into (e.g., equally divided into) two streams and then enters the side channel 640-2 and the internal channel 650-2. In some embodiments, the side flow divider 630-1 (630-2) divides more air flow into the inner channel 650-1 (650-2) than into the side channel 640-1 (640-2), for example, in one example, the volume ratio of the air flow divided into the inner channel 650-1 (650-2) and the side channel 640-1 (640-2) is about 70%:30%. The side channel 640-1 is connected to the side outlet 642-1. The side channel 640-2 is connected to the side outlet 642-2. The air flows in the side channel 640-1 and the side channel 640-2 are thus blown out from the side outlet 642-1 and the side outlet 642-2, respectively, and enter the adjacent area located outside the nozzle 110. In some embodiments, each opening of the side outlet 642-1 and the side outlet 642-2 has a length of about 0.1 mm. The side splitter 630-1 has an inner surface 644-1 and an outer surface 646-1. The side splitter 630-2 has an inner surface 644-2 and an outer surface 646-2. The outer surface 646-1 and the outer surface 646-2 are both convex surfaces. Due to the Coanda effect, the air flow blown out from the side outlet 642-1 and the side outlet 642-2 has a tendency to remain attached to the adjacent convex surface 646-1 and the convex surface 646-2, thereby forming two Coanda flows 652 flowing toward the main outlet 606 along the outer surface 646-1 and the outer surface 646-2. The inner surface 644-1 and the inner surface 644-2 can each be a flat surface or a convex surface that provides an inner side wall for the inner channel 650-1 and the inner channel 650-2 respectively. The outer surface 646-1 and the outer surface 646-2 have a profile length longer than the inner surface 644-1 and the inner surface 644-2, respectively. Therefore, Coanda flow 652 has a faster flow speed than the air flow remaining in inner passage 650-1 and inner passage 650-2. Therefore, the air pressure near outer surface 646-1 and outer surface 646-2 is lower than the air pressure in inner passage 650-1 and inner passage 650-2, respectively.In some embodiments, the openings of side outlets 642-1 and 642-2 are narrower than the cross-sectional openings of side channels 640-1 and 640-2, respectively, thereby ejecting even higher velocity Coanda stream 652 through side outlets 642-1 and 642-2. In some other embodiments, side channels 640-1 and 640-2 do not branch from subchannels 610-1 and 610-2, but are each connected to a separate gas pump (not shown) that is different from gas pump 604. This separate gas pump independently controls the volume and velocity of Coanda stream 652.

[0059] Compared to the surrounding air, the Coanda flow 652 has a higher momentum. Due to viscosity, the surrounding air is carried along with the Coanda flow 652. In fluid dynamics, Bernoulli's principle states that an increase in fluid velocity occurs simultaneously with a decrease in pressure. Therefore, a low pressure area is formed near the outer surface 646-1 and the outer surface 646-2. The air pressure increases in a gradient away from the outer surface 646-1 and the outer surface 646-2. This air pressure gradient compresses the surrounding air toward the outer surface 646-1 and the outer surface 646-2 and the main outlet 606, thereby forming a new air flow originating from the outer area of ​​the nozzle 110. This air flow is called Bernoulli flow 654.

[0060] In some embodiments, the nozzle 110 has a length (denoted as L1) measured from the opening of the main outlet 606 to the opening of the supply port 602, which is in the range of about 10 mm to about 30 mm (e.g., about 12 mm). The opening of the main outlet 606 is significantly smaller than the opening of the supply port 602. For example, the ratio of the length of the opening of the supply port 602 to the length of the main outlet 606 is in the range of about 4:1 to about 40:1. In some embodiments, the opening of the main outlet 606 is less than 1 mm (denoted as W2) in the direction Z, for example, from about 0.1 mm to about 0.5 mm. In some embodiments, the opening of the supply port 602 is from about 2 mm to about 4 mm (denoted as W1) in the direction Z, for example, about 2.5 mm. The opening of the main outlet 606 is also significantly smaller than the size of the internal channel 650-1 or the internal channel 650-2. The gas flow from the inner channel 650-1 and the gas flow from the inner channel 650-2 merge in the area near the end 620 and are ejected from the main outlet 606, thereby forming the laminar flow 130. In the adjacent area outside the main outlet 606, the Coanda flow 652 entrains and compresses the laminar flow 130 from both the upper and lower sides to suppress the diffusion of the laminar flow 130. In addition, the Bernoulli flow 654 also compresses the Coanda flow 652 and the laminar flow 130 from both sides. By synergistically integrating the Coanda effect and the Bernoulli effect, the nozzle 110 is configured to generate a laminar flow 130 with an ultra-thin thickness. In some embodiments, the laminar flow 130 has a thickness of less than 1 mm, for example, about 0.5 mm. The thickness of the laminar flow 130 is defined by the full width at half maximum (FWHM) of the flow velocity distribution. For example, if the laminar flow 130 has a maximum velocity v0 at the center of the flow and the velocity decreases to v0 / 2 at 0.25 mm from the center, the laminar flow 130 is considered to have a thickness of 0.5 mm (0.25 mm×2). In some embodiments, the Coanda flow 652 and the Bernoulli flow 654 merge into the laminar flow 130 and become part of the particle shield 130.

[0061] Fig. 7A is an exemplary second component 120 for receiving the particle shield 130 along Figure 1A . In the embodiment shown, the second component 120 is aligned at the same level as the nozzle 110 in the direction Z, providing a gas pressure gradient for the particle shield 130. After traveling a distance away from the nozzle 110, the laminar flow 130 begins to dissipate in the direction Z. One phenomenon is that the flow velocity decreases and the thickness of the laminar flow 130 increases. The second component 120 helps to compress the laminar flow 130 at the receiving (or capturing) end. The second component 120 has an exhaust port 702 coupled to an exhaust pump 704. In some embodiments, the exhaust pump 704 is a vacuum pump. The exhaust pump 704 provides a suction force Fexhaust , suction force F exhaust The suction laminar flow 130 flows into the main inlet 706 and then passes through the exhaust port 702. The second component 120 may also be referred to as a suction nozzle 120. In some embodiments, the suction force F exhaust is greater than the driving force F provided by the gas pump 604 at the other end of the nozzle 110 pump . Larger suction force F exhaust The suction nozzle 120 is enabled to better collect the dissipated gas molecules in the laminar flow 130. In one example, the suction force F exhaust is the driving force F pump The main inlet 706 is provided with a plurality of laminar flow ports 702, which are provided with a plurality of laminar flow ports 702. ...

[0062] The exhaust pump 704 forms a pressure gradient between the nozzle 110 and the suction nozzle 120. This pressure gradient drives the laminar flow 130 to enter the main inlet 706. The main inlet 706 is coupled to the channel 710 that guides the gas flow to the exhaust port 702. In some embodiments, the channel 710 includes two or more sub-channels, such as the upper sub-channel 710-1 and the lower sub-channel 710-2 in the illustrated embodiment. The suction nozzle 120 has a splitter 708, and the splitter 708 divides the gas flow equally into the upper sub-channel 710-1 and the lower sub-channel 710-2. The splitter 708 adjusts the flow direction and flow speed of the gas molecules at the extraction end of the laminar flow 130. In the illustrated embodiment, the splitter 708 has a spindle shape that tapers gradually at both the end 712 and the end 714. The end 712 and the end 714 can each have a rounded end or a pointed end. The selection of the end shape depends on the specific needs of the fluid dynamics control in various applications. In the illustrated embodiment, both the end 712 and the end 714 have pointed tips. In the illustrated embodiment, the end 712 extends from the opening of the main inlet 706, and the length (denoted as L2) of the suction nozzle 120 measured from the pointed tip of the end 712 to the opening of the exhaust port 702 is between about 10 mm and about 30 mm, for example, about 12 mm. In some other embodiments, the end 712 does not extend from the opening of the main inlet 706, and the length L2 measured from the opening of the main inlet 706 to the opening of the exhaust port 702 is between about 10 mm and about 30 mm, for example, about 12 mm.

[0063] The suction nozzle 120 has one or more side inlets 742 opened at its outer surface. The side inlet 742 is coupled to the exhaust pump 704 by the channel 710. Therefore, a pressure gradient is generated at the area around the side inlet 742 and in the channel 710. This pressure gradient drives the gas to flow along the outer surface 746 of the side splitter 730. In various embodiments, there may be one or more side splitters 730 (for example, two side splitters 730 are shown in FIG. 7). The side splitter 730 also has an inner surface 744. The outer surface 746 is a convex surface. Due to the Coanda effect, the air flow drawn into the side inlet 742 has a tendency to remain attached to the adjacent convex surface 746, thereby forming a Coanda flow 752 flowing from the main inlet 706 toward the side inlet 742 along the outer surface 746. The inner surface 744 can be a flat surface or a convex surface providing an inner side wall for the channel 710. The outer surface 746 has a profile length longer than the inner surface 744. Thus, Coanda flow 752 has a flow velocity that is faster than the flow velocity of the air flow within channel 710. Thus, the air pressure adjacent exterior surface 746 is lower than the air pressure within channel 710. In some embodiments, the volume ratio between the gas flow through side inlet 742 and the gas flow through main inlet 706 is about 1:1. In some embodiments, main inlet 706 has a larger gas flow intake than side inlet 742.

[0064] In the illustrated embodiment, the gas flows within the subchannel 710-1 and the subchannel 710-2 merge in a region near the end 714 of the flow splitter 708, and then the merged gas flow further merges with the Coanda flow 752 in the channel 710. In some embodiments, the side inlet 742 opens at a location between the main inlet 706 and the end 714 of the flow splitter 708, so that before the two subchannels 710-1 merge with the subchannel 710-2, the gas flows within the subchannel 710-1 and the subchannel 710-2 each separately merge with the Coanda flow 752. In yet another embodiment, the side inlet 742 is not coupled to the channel 710 or the exhaust pump 704, but is separately connected to a separate exhaust pump (not shown) that is different from the exhaust pump 704. This separate exhaust pump separately controls the volume and velocity of the Coanda flow 752.

[0065] Compared with surrounding air, Coanda flow 752 has higher momentum.Due to viscosity, surrounding air is taken away along with Coanda flow 652, but momentum is less.In fluid dynamics, Bernoulli's principle points out that the increase of fluid velocity and the reduction of pressure occur simultaneously.Therefore, low pressure area is formed at adjacent external surface 746.Along with being away from external surface 746, air pressure increases.This air pressure gradient compresses surrounding air towards external surface 746 and main outlet 706, thereby forms the new air stream of the outer area that originates from suction nozzle 120.This air stream is called Bernoulli flow 754.

[0066] In the vicinity outside the main inlet 706, the Coanda flow 752 entrains and compresses the laminar flow 130 from both the upper and lower sides to suppress the dispersion of the laminar flow 130. In addition, the Bernoulli flow 754 also compresses the Coanda flow 752 and the laminar flow 130 from both sides. By synergistically integrating the Coanda effect and the Bernoulli effect, the suction nozzle 120 is able to maintain a laminar flow 130 with an ultra-thin thickness even at the end of the propagation path. In some embodiments, the laminar flow 130 maintains a thickness of about 0.5 mm near the nozzle 110 and a thickness of less than about 0.75 mm near the suction nozzle 120.

[0067] Figure 7B Another embodiment of the suction nozzle 120 is shown. The suction nozzle 120 is substantially the same as Figure 6 The same nozzle 110 is shown, but with the supply port 602 ( Figure 6 ) is flipped to couple to the exhaust pump 704 so that the internal flow direction is reversed and the supply port 602 becomes the exhaust port 702 and the main outlet 606 ( Figure 6 ) becomes the main inlet 706. By reusing the nozzle as a suction nozzle, the system setup is simplified. The dimensions of the suction nozzle 120 (e.g., length (L2), opening (W3) of the main inlet 706, and opening (W4) of the exhaust port 702) are substantially the same as those of the suction nozzle 120. Figure 6 The dimensions of the nozzles 110 in FIG. 1 are the same (ie, L2=L1, W3=W2, W4=W1). Fig. 7A and Figure 7B The opening (W3) of the main entrance 706 in Figure 7B The opening in the main inlet 706 is smaller, coupled from the exhaust pump 704, however the smaller opening provides a stronger suction capability directly facing the nozzle on the other side compared to the larger opening, which also maintains the thin laminar flow 130. In some other embodiments, the opening (W3) of the main inlet 706 may be even smaller than the opening (W2) of the main outlet 606.

[0068] Figure 8 , FIG. 9A to FIG. 9B Other embodiments of the nozzle 110 and the suction nozzle 120 are shown. Figure 8 The nozzle 110 in FIG. 9 and the suction nozzle 120 in FIG. 9 are similar to the reference Figure 6 and FIG. 7A to FIG. 7B For ease of understanding, Figure 8 and FIG. 9A to FIG. 9B Reference numbers are reused in the .

[0069] Compare Figure 8 and Figure 6 The nozzle 110 has a difference in that Figure 8The nozzle 110 in FIG. 1 does not have a flow divider 608. Since there is no flow divider 608, the sub-channels 610-1 / 610-2 and the internal channels 650-1 / 650-2 ( Figure 6 ) merge into a gas / fluid communication channel 610. The side cover 609-1 (609-2) and the side diverter 630-1 (630-2) surround the channel 610 and can be considered to jointly provide a side wall 631 for the channel 610. In other words, the side cover 609-1 (609-2) and the side diverter 630-1 (630-2) can be considered as a side wall 631 divided into two sections by the side channel 640-1 (640-2) and the side outlet 642-1 (642-2). In some embodiments, the side wall 631 is a continuous section, but a side opening (e.g., a narrow slot) is provided to form the side channel 640-1 (640-2) and the side outlet 642-2 (642-2). Through the channel 610, a portion of the gas flow entering the supply port 602 travels on a straight line from the opening of the supply port 602 to the opening of the main outlet 606. The other part of the gas flow travels along the area adjacent to the inner sidewalls of the side covers 609-1 / 609-2 and the side splitters 630-1 / 630-2. The side outlets 642-1 / 642-2 stimulate the Coanda flow 652 along the outer surface of the nozzle 110, which further stimulates the Bernoulli flow 654 in the adjacent area of ​​the main outlet 606. The Coanda flow 652 and the Bernoulli flow 654 together compress the laminar flow 130 to obtain an ultra-thin thickness defined by the full width at half maximum (FWHM) of the flow velocity distribution of the particle shield, for example, less than 1 mm.

[0070] Compare Fig.9A and Fig. 7A The suction nozzle 120 in FIG. 1 is different in that Fig.9A The suction nozzle 120 in FIG. 1 does not have a flow divider 708. Since there is no flow divider 708, the sub-channel 710-1 and the sub-channel 710-2 ( Fig. 7A ) merge into a gas / fluid communication channel 710. A portion of the gas flow entering the main inlet 706 travels in a straight line pointing from the opening of the main inlet 706 to the opening of the exhaust port 702. The other portion of the gas flow entering the main inlet 706 travels along the area adjacent to the inner side wall of the side splitter 730. The side inlet 742 excites the Coanda flow 752 along the outer surface of the suction nozzle 120, which further excites the Bernoulli flow 754 in the adjacent area of ​​the main inlet 706. The Coanda flow 752 and the Bernoulli flow 754 together compress the laminar flow 130, preventing the laminar flow 130 from further expanding after traveling a distance from the nozzle 110.

[0071] Similar to Figure 7B The suction nozzle 120 in the Fig. 9B Another embodiment of the suction nozzle 120 is shown. This other embodiment of the suction nozzle 120 essentially uses the same Figure 8 The same nozzle 110 is shown, but with the supply port 602 ( Figure 8 ) is flipped to couple to the exhaust pump 704 so that the internal flow direction is reversed and the supply port 602 becomes the exhaust port 702 and the main outlet 606 ( Figure 8 ) becomes the main inlet 706. By reusing the nozzle as a suction nozzle, the system setup is simplified. The dimensions of the suction nozzle 120 (e.g., length (L2), opening (W3) of the main inlet 706, and opening (W4) of the exhaust port 702) are substantially the same as those of the suction nozzle 120. Figure 8 The dimensions of the nozzles 110 in FIG. 1 are the same (ie, L2=L1, W3=W2, W4=W1). Fig.9A and Fig. 9B The opening (W3) of the main entrance 706 in Fig. 9B The opening in the main inlet 706 is smaller, coupled from the exhaust pump 704, however the smaller opening provides a stronger suction capability directly facing the nozzle on the other side compared to the larger opening, which also maintains the thin laminar flow 130. In some other embodiments, the opening (W3) of the main inlet 706 may be even smaller than the opening (W2) of the main outlet 606.

[0072] FIG. 10A to FIG. 10D Some other embodiments of nozzle 110 are shown. Fig. 10A The nozzle 110 in Figure 8 The nozzle 110 discussed in . The nozzle 110 has a side wall 631 in which a gas / fluid communication channel 610 is defined. The channel 610 couples the supply port 602 to the main outlet 606. The supply port 602 has an opening that is larger than the main outlet 606. The side wall 631 is symmetrical with respect to a central imaginary line pointing from the supply port 602 to the main outlet 606 along the X direction. Each side wall 631 has a side opening that couples the channel 610 to an external adjacent area of ​​the nozzle 110. The end of the side opening that interfaces with the external adjacent area is referred to as a side outlet 642. In some embodiments, the side opening divides each side wall 631 into two separate segments. In some embodiments, the side opening is a narrow slot so that each side wall 631 remains a continuous segment. Relative to the position of the side outlet 642 in the X direction, the channel 610 is considered to include a front channel (having a length La) that interfaces with the supply port 602 and a rear channel (having a length Lb) that interfaces with the main outlet 606. In Fig. 10A In the illustrated embodiment, La is smaller than Lb, and the ratio of La to Lb is about 1:1.1 to about 1:5, for example about 1:3. Fig. 10B The nozzle 110 in Fig. 10AA side outlet 642 positioned closer to the main outlet 606 in the middle, such that L-a is equal to or greater than L-b, and the ratio of L-a to L-b is from about 1:1 to about 5:1, for example about 3:1. In some embodiments, the nozzle 110 may have a plurality of side outlets 642 that open at each side wall 631, as Fig. 10C and Fig. 10D shown. Fig. 10C The nozzle 110 in [reference] has two side outlets 642-a and 642-b. Each side outlet excites a corresponding Coanda flow that propagates along the outer surface of the side wall 631 towards the main outlet 606. Accordingly, the channel 610 is considered to include a front channel (having a length L-a), an intermediate channel (having a length L-b), and a rear channel (having a length L-c). In some embodiments, L-a, L-b, and L-c have equal lengths. In some embodiments, the front channel is longer than the intermediate channel, and the intermediate channel is longer than the rear channel (L-a > L-b > L-c). In some other embodiments, vice versa (L-a < L-b < L-c). Fig. 10D The nozzle 110 in [reference] has three side outlets 642-a, 642-b, and 642-c. Accordingly, the channel 610 is considered to include a front channel (having a length L-a), a first intermediate channel (having a length L-b), a second intermediate channel (having a length L-c), and a rear channel (having a length L-d). In some embodiments, the lengths of these channel portions have the relationship of L-a > L-b = L-c = L-d. In some embodiments, the lengths of these channel portions have the relationship of L-a > L-b > L-c > L-d. In some other embodiments, the lengths of these channel portions have the relationship of L-a < L-b < L-c < L-d.

[0073] FIG. 11A to FIG. 11C is a perspective view of an apparatus 800 including a nozzle 110 and a suction nozzle 120 in various embodiments. In Fig.11A [reference], the apparatus 800 includes a nozzle 110 and a suction nozzle 120 as shown in Figure 6 and Fig. 7A shown. As an alternative, the suction nozzle 120 may be the suction nozzle shown in Figure 7B [reference]. Similarly, in Fig. 11B [reference], the apparatus 800 includes a nozzle 110 and a suction nozzle 120 as shown in Figure 8 and Fig.9A shown. As an alternative, the suction nozzle 120 may be the suction nozzle shown in Fig. 9B [reference]. In Fig.11A or Fig. 11B [reference], the apparatus 800 is configured to generate a particulate shield 130 between the nozzle 110 and the suction nozzle 120. To generate the particulate shield 130, the nozzle 110 is driven by a gas pump with a driving force F pump and the suction nozzle 120 is driven by an exhaust pump with a suction force Fexhaust drive. Figure 8 The arrow in FIG. 1 indicates the direction of gas flow from the gas pump to the exhaust pump. To maintain the particle shield 130 in a laminar flow, the suction force F exhaust is configured to be at least equal to or stronger than the driving force F pump In one embodiment, the suction force F exhaust is the driving force F pump Twice as much. Driving force F pump And suction force F exhaust The gas velocity fed into the nozzle 110 and the gas velocity leaving the suction nozzle 120 can be characterized as the gas velocity fed into the nozzle 110 and the gas velocity leaving the suction nozzle 120, respectively. In one example, the gas velocity fed into the nozzle 110 is about 200 meters per second (m / s) and the gas velocity leaving the suction nozzle 120 is about 200 m / s (F exhaust =F pump In another example, the gas flow velocity fed into the nozzle 110 is about 200 meters per second (m / s) and the gas flow velocity leaving the suction nozzle 120 is about 500 m / s (F exhaust >F pump ). The gas flow traveling between the nozzle 110 and the suction nozzle 120 has a speed much faster than the speed fed into the nozzle 110 , for example, about 6 to about 20 times the speed fed into the nozzle 110 .

[0074] To help prevent particles or contaminants from falling on or contacting the surface of the object 140, the particle shield 130 overlaps the object 140 and is physically separated from the object 140. In some embodiments, the particle shield 130 has a width of about 300 mm along the longitudinal direction of the nozzle 110 and a length of about 300 mm to about 450 mm along the direction pointing from the nozzle 110 to the suction nozzle 120. In various embodiments, the object 140 may be a mask (e.g., an extreme ultraviolet mask), a photomask, a substrate, a wafer, an optical element (e.g., a reflector), or an optical illumination aperture.

[0075] The device 800 synergistically excites both Coanda flow and Bernoulli flow around the nozzle 110 and the suction nozzle 120. As described above, the Coanda flow and the Bernoulli flow help to compress the particle shield 130 from both the upper and lower sides, thereby obtaining an ultra-thin laminar flow, such as a laminar flow with a thickness of about 0.5 mm. For particle shield applications, ultra-thin laminar flows have several benefits. For example, in extreme ultraviolet lithography applications, there is inevitably some energy loss associated with the transmission of extreme ultraviolet light through the particle shield, which is expressed as transmission loss. Due to the thinner laminar flow, the extreme ultraviolet light transmission loss can be greatly reduced. In one example, by using an H2 laminar gas shield in a near-vacuum environment (pressure of approximately 0.021 Torr), the extreme ultraviolet transmission loss of each gas shield is less than approximately 0.0002%.

[0076] Another benefit of ultra-thin laminar flow is that the thinner the laminar flow, the greater the gas flow velocity can be obtained, which will more effectively blow particles away from the protected surface. The probability of eddy or turbulence disturbing the laminar flow is based on the Reynolds number Re. The Reynolds number Re can be calculated based on the shape, velocity, viscosity, density and other factors of the fluid flow. When the Reynolds number Re is greater than 2100, eddy or turbulence may occur and disturb the laminar flow. In the embodiment shown, the optimization of the system (nozzle geometry, surface roughness, flow velocity, etc.) using computational fluid dynamics (CFD) will ensure that the Reynolds number Re is less than 2000. The Reynolds number Re is proportional to the product of the laminar velocity and thickness. Therefore, in order to maintain a relatively small Reynolds number Re, reducing the laminar thickness will allow a higher laminar velocity, which effectively means a stronger particle shielding ability. Due to the Bernoulli effect, a higher laminar velocity will also promote a stronger pressure gradient, which will form a stronger entrainment force to maintain the laminarity of the particle shielding body. Due to the Bernoulli effect, the pressure gradient is proportional to the velocity of the fluid. Therefore, the higher the laminar velocity, the stronger the pressure gradient, which in turn creates a stronger Bernoulli flow that further compresses the laminar flow.

[0077] In some embodiments, Figure 6 , Figure 8 and FIG. 10A to FIG. 10D The nozzle shown can also be used as a suction nozzle by coupling the supply port 602 to an exhaust pump so that the direction of travel of the gas flow in the nozzle is reversed. Fig. 11C Such an example is given. Fig. 11C The nozzle 110 and the suction nozzle 120 are Figure 8 The nozzle 110 has its supply port 602 coupled to the supply pump, while the suction nozzle 120 has its supply port 602 coupled to the discharge pump. In one embodiment, the nozzle 110 has only a driving force Fpump In the case of a supply pump having a speed of about 200 m / s, the gas flow ejected from the nozzle 110 has a speed of at least about 1200 m / s (F pump In another embodiment, the nozzle 110 has a driving force F pump The supply pump and suction nozzle 120 have a suction force F of about 200 m / s. exhaust In the case of a discharge pump of about 200 m / s, the gas flow ejected from the nozzle 110 has a velocity of about 1800 m / s (F pump In another embodiment, the nozzle 110 has a supply pump with a driving force of about 200 m / s and the suction nozzle 120 has a speed greater than F. pump The suction force F exhaust In the case of an exhaust pump, the gas flow ejected from the nozzle 110 can reach about 4000m / s (F pump Since kinetic energy is proportional to the square of the flow velocity, using a stronger exhaust pump to accelerate the particle shield by 20 times is equivalent to increasing the kinetic energy of the particle shield by about 400 times, which will significantly enhance the particle shielding. As a benchmark, in either case, the gas flow ejected from the nozzle 110 is faster than the speed of sound in air (about 340 m / s). Fig.13 In comparison, the conventional rectangular nozzle 760 (also referred to as the parallel plate nozzle 760 because its parallel plates 762 define the straight air flow channel 764) has no side outlet to stimulate the Coanda flow and the Bernoulli flow, and the supply pump has a driving force F of about 200 m / s. pump In the case of the conventional rectangular nozzle 760, the gas flow 766 can only be provided at a speed of about 600 m / s (3 times), which is much slower than other nozzles provided in the present disclosure. The thickness of the particle shield provided by the conventional rectangular nozzle can also be about 2 to 3 times thicker than the particle shield 130 produced by other nozzles in the present disclosure.

[0078] Fig.12is a schematic diagram of an EUV lithography system 900 according to one or more embodiments. The EUV lithography system 900 includes an apparatus for producing a particle shield 930 (e.g., particle shield 930-1, particle shield 930-2, particle shield 930-3, particle shield 930-4, and particle shield 930-5) similar to the particle shield 130. The EUV lithography system 900 includes an EUV mask 940, a plurality of reticle masking (REMA) blades 942 (e.g., REMA blade 942-1, REMA blade 942-2, and REMA blade 942-3), a radiation source 944, a plurality of reflectors or mirrors 946, and a set of optical illumination apertures 948 (e.g., aperture 948-1 and aperture 948-2). The radiation source 944 can provide EUV light having a wavelength of approximately 13.5 nm. A beam of extreme ultraviolet light 950 produced by extreme ultraviolet radiation source 944 propagates to reflector 946 and aperture 948 along optical path, and then arrives mask 940. Extreme ultraviolet light 950 is reflected by mask 940, and then forms image on wafer. REMA blade 942 blocks the extreme ultraviolet light that may leak through the pinhole in the boundary area and selectively blocks the mask alignment target (reticle alignment target) so that the mask alignment target will not be printed on the wafer. Each REMA blade 942 can be independently moved in the horizontal direction by the linear platform mechanism (linear stage mechanism) driven by a linear motor. In certain embodiments, the distance between mask 940 and REMA blade 942-1 is between about 10mm and about 100mm. In the embodiment shown, REMA blade 942-2 and REMA blade 942-3 are stacked below REMA blade 942-1.

[0079] The lithography system 900 also includes a plurality of nozzles and suction nozzles similar to the corresponding components discussed above in conjunction with the apparatus 800, such as a first nozzle 910, a first suction nozzle 920, a second nozzle 910', and a second suction nozzle 920'. The first particle shield 930-1 is located between the mask 940 and the REMA blade 942-1. The second particle shield 930-2 is located between the stack of REMA blades, such as between the REMA blade 942-1 and the REMA blade 942-2 / 942-3. Therefore, the REMA blade 942-1 is sandwiched between the first particle shield 930-1 and the second particle shield 930-2. Both the first particle shield 930-1 and the second particle shield 930-2 help prevent particles or contaminants from adhering to or falling on the mask 940 and the REMA blade 942. The third particle shield 930-3 and the fourth particle shield 930-4 cover the optical illumination opening 948-1 and the optical illumination opening 948-2, respectively, which helps prevent particles or contaminants from entering the mask chamber above. Depending on the location of the optical illumination opening 948-1 and the optical illumination opening 948-2, the third particle shield 930-3 and the fourth particle shield 930-4 may be parallel to or may not be parallel to the first particle shield 930-1 and the second particle shield 930-2. In the embodiment shown, the third particle shield and the fourth particle shield 930-3 / 930-4 form an angle of about 40 degrees to about 80 degrees relative to the first particle shield 930-1 and the second particle shield 930-2. In some embodiments, the particle shield 930 includes a non-solid material particle air shield. For example, the particle shield 930 may include hydrogen, ambient air, helium, nitrogen, or an inert gas, such as a H2 laminar jet. In some embodiments, the particle shields 930 may include different gases. In some embodiments, the thickness of each particle shield 930 is in the range of about 0.5 mm to about 2 mm. In some embodiments, each particle shield 930 has a transmission loss of less than about 0.0002% for extreme ultraviolet light. In various embodiments, depending on the cleanliness requirements, one or more sets of components for creating the particle shield are positioned adjacent to the surface of any of the radiation source 944, the reflector 946 (e.g., particle shield 930-5), or the wafer. In some embodiments, one or more of the particle shields 930 may further include a combination of energy gradient forces and velocity-dependent forces. For example, the first particle shield 930-1 includes a laminar gaseous flow and the second particle shield 930-2 includes an electromagnetic Lorentz force or a thermal gradient force.

[0080] Now refer to Fig.14 . Fig.14 Another exemplary nozzle 110 for producing a particle shield 130 is shown along Figure 1A1-1 . In the illustrated embodiment, the first component 110 receives a gas supply from a supply port 602 coupled to a supply source 604 and ejects the particle shield 130 from a distal end 618. In some embodiments, the supply source 604 is a gas pump that provides ambient air, nitrogen, hydrogen, an inert gas, or a combination thereof. The gas pump 604 uses a gas pump denoted by F pump The driving force of the gas stream is pumped into the supply port 602. The gas stream is then ejected from the nozzle 110, thereby forming a particle shield 130. As described above, the particle shield 130 formed by gas molecules can also be referred to as a non-solid matter particle air shield. In some embodiments, the particle shield 130 is a laminar flow. In the illustrated embodiment, the particle shield 130 is a laminar jet that has a supersonic gaseous flow velocity (e.g., up to 1800 m / s) when leaving the nozzle 110 and can travel a long distance into the surrounding medium without substantially dissipating.

[0081] The nozzle 110 has a side wall 609 defining a gas communication channel 610. The side wall 609 includes two side covers 609-1 and 609-2. The nozzle 110 also has a flow divider 608 between the side cover 609-1 and the side cover 609-2. The flow divider 608 divides the gas communication channel 610 into an upper sub-channel 610-1 and a lower sub-channel 610-2 and also divides the output port 606 into an upper sub-output port 606-1 and a lower sub-output port 606-2. The gas flow from the supply port 602 is divided into two equal flows and enters the two sub-channels 610-1 and 610-2. In the illustrated embodiment, the flow divider 608 has a first end portion 608-1 adjacent to the supply port 602, a central portion 608-2 adjacent to the output port 606, and a second end portion 608-3 protruding from the output port 606. The first end portion 608-1, the central portion 608-2 and the second end portion 608-3 form a spindle shape, and the central portion 608-2 of the spindle shape is the widest part and gradually narrows toward both ends. The maximum width W6 is positioned in the gas communication channel 610 and adjacent to the output port 606. In the embodiment shown, the first end portion 608-1 has a rectangular shape with a width of W7. In some embodiments, the ratio of W6 / W7 is between about 1.5 and about 8. The maximum width W6 gradually narrows with a smooth surface to become the rectangular shape of the first end portion 608-1. The smooth surface may have a curved shape. In the embodiment shown, the portion of the sidewall 609 adjacent to the supply port 602 has an inner surface parallel to the surface of the first end portion 608-1. The distance between the parallel surfaces (also the input opening of the subchannel 610-1 / 610-2) is from about 2mm to about 4mm (expressed as W1) in the direction Z, for example, about 2.5mm. The portion of the sidewall 609 adjacent to the output port 606 has an inner surface that is curved toward the central portion 608-2 of the diverter 608. Therefore, the width of the subchannel 610-1 / 610-2 is sharply reduced toward the output port 606. The opening of the sub-output port 606-1 / 606-2 is thus significantly smaller than the input opening of the subchannel 610-1 / 610-2. In some embodiments, the opening (denoted as W2) of the sub-output port 606-1 / 606-2 is within the range of about 0.1mm to about 0.5mm, for example, about 0.3mm. The third portion 608-3 of the diverter 608 protrudes out of the output port 606. In the embodiment shown, the third portion 608-3 has a rounded end 618. In an alternative embodiment, the end 618 is pointed. The shape of the end 618 depends on the specific needs of fluid dynamics control in various applications. The maximum width W6 gradually narrows toward the end 618 with a smooth surface that converges at the end 618. The smooth surface may have a curved shape.

[0082] Along the air flow path entering the supply port 602, the gas flow is first equally divided into two sub-gas flows by the flow divider 608, wherein one sub-gas flow flows through the upper sub-channel 610-1 and the other flows through the lower sub-channel 610-2. Each sub-channel 610-1 / 610-2 has a channel width that is sharply reduced in a short distance, thereby forming a high pressure in the vicinity of the sub-output port 610-1 / 610-2. The high pressure ejects the two sub-flows out of the sub-output port 610-1 / 610-2. Due to the Coanda effect, the gas flow leaving the sub-output port 610-1 / 610-2 has a tendency to remain attached to the adjacent external surface of the third part 608-3, thereby forming two Coanda flows 652 flowing along the external surface toward the end 618. Compared with ambient air, the Coanda flow 652 has a higher momentum. Due to viscosity, ambient air is taken away together with the Coanda flow 652. In fluid dynamics, the Bernoulli principle states that the increase in fluid velocity occurs simultaneously with the decrease in pressure. Therefore, a low pressure zone is formed adjacent to the outer surface of the third portion 608-3. The air pressure increases in a gradient away from the outer surface of the third portion 608-3. This air pressure gradient compresses the surrounding air toward the outer surface of the third portion 608-3 and the end 618, thereby forming a new air flow originating from the outer area of ​​the nozzle 110. This air flow is referred to as a Bernoulli flow 654.

[0083] In the vicinity near the end 618, the two Coanda flows 652 meet and merge into one laminar flow 130. The Bernoulli flow 654 entrains and compresses the laminar flow 130 from both the upper and lower sides to suppress the dispersion of the laminar flow 130. By synergistically integrating the Coanda effect and the Bernoulli effect, the nozzle 110 is configured to produce a laminar flow 130 with an ultra-thin thickness. In some embodiments, the laminar flow 130 has a thickness of less than 1 mm, for example, about 0.5 mm. The thickness of the laminar flow 130 is defined by the full width at half maximum (FWHM) of the flow velocity distribution. For example, if the laminar flow 130 has the highest flow velocity v0 at the center of the flow and the flow velocity decreases to v0 / 2 at 0.25 mm from the center, the laminar flow 130 is considered to have a thickness of 0.5 mm (0.25 mm×2). In some embodiments, the Bernoulli flow 654 merges into the laminar flow 130 and becomes part of the laminar flow 130. Furthermore, experiments have shown that, under a driving force of 500 Pa from pump 604, Fig.14 The nozzle design shown by itself (without the suction nozzle) is able to achieve a velocity v0 of about 1800 m / s. This design provides a simplified solution for the device for producing a particle shield, by which the suction nozzle becomes optional.

[0084] Fig.151 is a schematic diagram of an EUV lithography system 1000 according to one or more embodiments. Although EUV lithography system 1000 is shown as having components in a certain configuration, it should be understood that the disclosed incident channels for providing an EUV radiation travel path from an EUV radiation source toward an EUV photomask can also be implemented in an EUV lithography system with additional components (e.g., additional mirrors) or with fewer components (e.g., fewer mirrors).

[0085] EUV lithography system 1000 includes an EUV radiation source 1002 configured to supply EUV radiation 1114 (i.e., radiation having a wavelength between approximately 10 nm and approximately 130 nm (e.g., approximately 13.5 nm)) to an EUV photomask 1006 having a patterned multi-layer reflective surface. In some embodiments, EUV radiation source 1002 may include a primary laser 1102, a fuel droplet generator 1106, and a collector mirror 1112. Fuel droplet generator 1106 is configured to provide fuel droplets 1108, such as tin droplets, that are struck by a primary laser beam 1104 generated by primary laser 1102. Striking fuel droplets 1108 with primary laser beam 1104 generates a plasma 1110 including ions that emit EUV radiation 1114. The EUV radiation 1114 output from the EUV radiation source 1002 is provided to the focusing optical device 1120 through the intermediate focusing unit 1116. In some embodiments, the focusing optical device 1120 includes a first surface 1122a and a second surface 1122b configured to focus the EUV radiation 1114 and a reflector 1124 configured to reflect the EUV radiation 1114 toward the EUV mask 1006.

[0086] The EUV mask 1006 is configured to selectively reflect the EUV radiation 1114 to a projection optics 1130, which projects a pattern onto a layer of photosensitive material (e.g., photoresist) disposed on a semiconductor workpiece 1132. In some embodiments, the projection optics 1130 may include a series of mirrors 1130a to 1130d that are used to reduce the size of the pattern carried by the EUV radiation 1114. The series of mirrors 1130a to 1130d transmit the EUV radiation 1114 to a layer of photosensitive material (e.g., photoresist) disposed on a semiconductor workpiece (e.g., a wafer) 1132. The EUV radiation 1114 patterns the layer of photosensitive material so that subsequent processing can be performed on selected areas of the semiconductor workpiece 1132. To produce the pattern, the EUV mask 1006 includes a patterned absorbing material disposed on a front surface of the EUV mask 1006. The patterned absorbent material is configured to absorb EUV radiation 1114 such that reflected light of EUV radiation 1114 transmits the pattern defined by EUV mask 1006 .

[0087] REMA blades 1142-1 and REMA blades 1142-2 (collectively referred to as REMA blades 1142) block extreme ultraviolet radiation 1114 that may leak through the pinholes and selectively block the mask alignment target so that the mask alignment target is not printed on the semiconductor workpiece (e.g., wafer) 1132. Each REMA blade 942 can be independently moved in the horizontal direction by a linear stage mechanism driven by a linear motor. In some embodiments, the distance between the mask 1106 and the REMA blade 1142 is in the range of about 10 mm to about 100 mm.

[0088] Before reaching REMA blade 1142 and EUV mask 1006 in sequence, EUV radiation 1114 travels through an optical path referred to as incident channel 1150. Incident channel 1150 may be defined by housing member 1154. Housing member 1154 may be made of radiation absorbing material, such as lead or tungsten. Incident channel 1150 has an input port and an outlet port. In the illustrated embodiment, focusing optics 1120 are positioned between the input port and EUV radiation source 1002. Alternatively, focusing optics 1120 may be positioned within incident channel 1150. The input port may have an opening larger than the outlet port, so that incident channel 1150 has a funnel shape. REMA blade 1142 is positioned between the outlet port of incident channel 1150 and EUV mask 1006. Similarly, after reflecting from the EUV mask 1006, the EUV radiation 1114 travels through an optical path referred to as a reflection channel 1152 before reaching the semiconductor workpiece 1132. The reflection channel 1152 may also be defined by a housing member 1154. The reflection channel 1152 has an input port and an output port. In the illustrated embodiment, the projection optics 1130 are positioned between the output port and the semiconductor workpiece 1132. Alternatively, the projection optics 1130 may be positioned within the reflection channel 1152. The REMA blade 1142 is positioned between the input port of the reflection channel 1152 and the EUV mask 1006.

[0089] The impact of the laser on the fuel droplets 1108 while generating the EUV radiation 1114 may also form metal particles 1160, such as tin particles. The metal particles 1160 travel with the EUV radiation 1114 through the incident channel 1150 toward the EUV mask 1006. The metal particles 1160 may adhere to the surface of the EUV mask 1006. The metal particles 1160 on the EUV mask 1006 potentially block the EUV radiation 1114 from being incident on the EUV mask 1006 and prevent accurate transfer of the pattern of the EUV mask 1006. The metal particles 1160 may also adhere to the surfaces of other optical equipment in the optical path and potentially scatter the light contacting these elements and reduce the accuracy of the pattern transfer. The EUV lithography system 1000 further includes a plurality of nozzles 110 that generate a plurality of particle shields 130 located in the incident channel 1150, thereby forming a particle shield array in the incident channel 1150. In the illustrated embodiment, the nozzles 110 include no less than three nozzles 110 of the same type, and the nozzles 110 are combined with the above Figure 6 , Figure 8 , FIG. 10A to FIG. 10D and Fig.14 One of the corresponding components discussed is similar, such as the first nozzle 110-1, the second nozzle 110-2, and the third nozzle 110-3. The nozzle 110-1, the nozzle 110-2, and the nozzle 110-3 produce a first particle shield 130-1, a second particle shield 130-2, and a third particle shield 130-3, respectively. The particle shield 130 is a laminar jet with strong momentum and can travel a long distance into the surrounding medium without substantially dissipating. In some embodiments, the extreme ultraviolet lithography system 1000 includes more than three nozzles 110, and the more than three nozzles 110 produce more than three particle shields 130 located in the incident channel 1150, such as six nozzles 110 in a specific example. The number of particle shields 130 required depends on the system requirements.

[0090] Fig.16 Experimental results showing the effect of applying different numbers of particle shields 130 to incident metal particles are shown. Line 1202 represents the relationship between the normalized particle size (X-axis) and the corresponding maximum velocity V (Y-axis) of the incident particles recorded at the input port of the incident channel 1150. For example, for a metal particle size of half the unit size (0.50), the maximum velocity V recorded is about 100 m / s; for a metal particle size of about 5 times the unit size, the maximum velocity V recorded is about 40 m / s. Line 1204 represents the effect of applying different numbers of particle shields 130 to the incident metal particles when no particle shield array is deployed in the incident channel 1150, but a second type of nozzle (e.g., with Fig.13The particle rejection performance of the system when the associated parallel plate nozzle 760) is positioned outside the exit port of the incident channel 1150 (for example, between the EUV mask 1006 and the REMA blade 1142). Two data points are highlighted on line 1204, namely point 1206 and point 1208. Point 1206 shows that for a metal particle size that is half (0.5) of the unit size, the maximum velocity V that the system can block is approximately 20 m / s. Therefore, corresponding incident particles with velocities ranging from 20 m / s to 100 m / s will reach the EUV mask 1006. Point 1208 shows that for a metal particle size that is approximately 5 times the unit size, the maximum velocity V that the system can block is approximately 5 m / s. Therefore, corresponding incident particles with velocities ranging from 5 m / s to 40 m / s will reach the EUV mask 1006. In other words, the optical path is for Fig.15 The EUV lithography system 1000 is almost transparent to the incident metal particles 1160 in the EUV lithography system 1000. To protect the EUV mask (not explicitly shown) in the EUV mask 1006, the EUV mask must be mounted on a pellicle. The pellicle includes a thin film that is configured to prevent contaminant particles from landing on the EUV mask and degrading the performance of the EUV lithography system 1000. However, in some systems, the pellicle absorbs up to 35% of the EUV radiation energy and severely reduces system throughput.

[0091] Line 1210 represents the particle rejection performance of the system when an array of particle shields formed by three laminar jets is deployed in the incident channel 1150. Two data points are highlighted on line 1210, namely point 1206' and point 1208'. Point 1206' shows that for a metal particle size that is half (0.5) of the unit size, the maximum velocity V that the system can block is about 90 m / s, which is much greater than the velocity represented by point 1206. Therefore, corresponding incident particles with a velocity in a narrow range of 90 m / s to 100 m / s will likely reach the extreme ultraviolet light mask 1006. Point 1208' shows that for a metal particle size that is about 5 times the unit size, the maximum velocity V that the system can block is about 35 m / s. Therefore, corresponding incident particles with a velocity in a narrow range of 35 m / s to 40 m / s will likely reach the extreme ultraviolet light mask 1006. In other words, the particle shield array in the incident channel 1150 blocks most of the incident metal particles 1160. Similarly, line 1206 represents the particle rejection performance of the system when the particle shield array formed by six laminar jets is deployed in the incident channel 1150. As shown, line 1206 is above line 1202, which means that the particle shield array is able to block substantially all metal particles regardless of particle size, even when the metal particles are incident at the maximum recorded speed. With the help of the particle shield array, the EUV mask 1006 can be pellicle-free, for example, an EUV reticle that is not mounted on a pellicle. In the absence of a pellicle that absorbs EUV radiation energy, production throughput can be increased by 35% in some systems.

[0092] Return to reference Fig.15 , although the nozzle 110 is also sufficient to work without the suction nozzle (e.g. Fig.14 110), but the suction nozzle and the nozzle 110 may be used in pairs as needed to further increase the gaseous flow velocity of the particle shield. For example, for three nozzles 110 disposed on one side wall of the incident channel 1150, three paired suction nozzles (not explicitly shown) may be disposed on opposite side walls of the incident channel 1150.

[0093] In some embodiments, the particle shield 130 closer to the EUV radiation source 1002 (e.g., the particle shield 130-3) has a greater gas flow velocity and correspondingly has a larger size to cover a larger opening area near the input port of the incident channel 1150; the particle shield 130 closer to the EUV light mask 1006 (e.g., the particle shield 130-1) has a smaller gas flow velocity (but still supersonic) and correspondingly has a smaller size to cover a smaller opening area near the output port of the incident channel 1150. In addition, the particle shield 130 closer to the EUV radiation source 1002 (e.g., the particle shield 130-3) may have an inclination angle toward the incident direction of the metal particles 1160, so that the velocity of the laminar flow has a component directly opposite to the incident direction of the metal particles 1160, which enhances the particle shielding capability. In the illustrated embodiment, the first particle shield 130-1 is substantially parallel to the top surface of the EUV light mask 1006, the second particle shield 130-2 is tilted downward and forms an angle of about 5° to about 15° relative to the top surface of the EUV light mask 1006, and the third particle shield 130-3 is further tilted downward and forms an angle of about 30° to about 45° relative to the top surface of the EUV light mask 1006.

[0094] Still refer to Fig.15 , the lithography system 1000 also includes one or more nozzles 760 of a second type different from the nozzle 110. In the illustrated embodiment, the nozzle 760 is a combination of the above Fig.13 The parallel plate nozzles of the discussion of the corresponding parts are similar, such as the first nozzle 760-1 and the second nozzle 760-2. The first particle shield 766-1 produced by the first nozzle 760-1 is located between the extreme ultraviolet mask 1006 and the REMA blade 1142. The second particle shield 766-2 produced by the second nozzle 760-2 is located between the REMA blade 1142 and the outlet port of the incident channel 1150. Each of the particle shield 766-1 and the particle shield 766-2 is parallel to the top surface of the extreme ultraviolet mask 1006. In some embodiments, each of the particle shield 766-1 and the particle shield 766-2 has a slower gaseous flow velocity and a correspondingly larger thickness and smaller size than any particle shield 130 positioned within the incident channel 1150. One consideration is that the area adjacent to the EUV mask 1006 is much more confined than the area within the entrance channel 1150, and using a particle shield with a lower gaseous flow velocity can avoid exciting turbulence in the confined area. Fig.15As shown, particle shields 766-1 and 766-2 intersect both the optical path of incident EUV radiation toward the EUV light mask and the optical path of reflected EUV radiation toward the workpiece 1132. In contrast, particle shields 130-1, 130-2, and 130-3 intersect only the optical path of incident EUV radiation toward the EUV light mask. In the illustrated embodiment, the reflective channel 1152 is free of a particle shield array. Alternatively, a particle shield array similar to that in the incident channel 1150 may also be disposed in the reflective channel 1152.

[0095] One aspect of the present description relates to an apparatus for generating a plurality of particle shields. The at least one particle shield comprises a first component and a second component. The first component and the second component can be used to form a first particle shield of the at least one particle shield for blocking particles from contacting an adjacent surface of an object, the first particle shield is substantially parallel to the adjacent surface of the object and physically separated from the adjacent surface of the object, and the first particle shield comprises an energy gradient force or a velocity gradient force.

[0096] Another aspect of the present description relates to a photolithography system comprising a photomask, a slit, at least one optical element, a first device for producing a first particle shielding volume, and a second device for producing a second particle shielding volume, wherein the slit is located between the first particle shielding volume and the second particle shielding volume.

[0097] Another aspect of the present description relates to a method for photolithography in semiconductor manufacturing. The method includes positioning a shield generator between a photomask and a slit; forming a particle shield by the shield generator to help prevent particles from adhering to a surface of the photomask or a surface of the slit and to remove particles along an optical path, wherein the shield generator is located between the photomask and the slit; and performing exposure to transfer one or more patterns in the photomask to a substrate or a layer on the substrate.

[0098] Another aspect of this description relates to a device for producing laminar flow. The device includes a nozzle and a suction nozzle, wherein the nozzle and the suction nozzle are operable to form a laminar flow, for blocking the adjacent surface of the particle contact object, wherein the nozzle includes a main outlet for blowing out the laminar flow, wherein the nozzle is configured to produce a Coanda flow along the outer surface of the nozzle, and wherein the suction nozzle is configured to provide a gas pressure gradient for the laminar flow. In some embodiments, the Coanda flow compresses the laminar flow in the adjacent area of ​​the main outlet. In some embodiments, the Coanda flow excites the Bernoulli flow to further compress the laminar flow in the adjacent area of ​​the main outlet. In some embodiments, the nozzle includes a side outlet for blowing out the Coanda flow. In some embodiments, the flow rate ratio of the side outlet to the main outlet is about 1:1. In some embodiments, the suction nozzle has a main inlet for receiving the laminar flow and a side inlet for producing another Coanda flow along the outer surface of the suction nozzle. In some embodiments, the other Coanda flow compresses the laminar flow in the adjacent area of ​​the main inlet. In some embodiments, the main inlet has an opening wider than the main outlet. In some embodiments, the nozzle is coupled to a first pump and the suction nozzle is coupled to a second pump, and wherein the second pump provides a force stronger than the first pump. In some embodiments, the laminar flow has a Reynolds number less than 2000. In some embodiments, the ratio of the speed of the laminar flow after flowing through the nozzle to the speed before flowing through the nozzle is about 9:1 to about 20:1. In some embodiments, the speed of the laminar flow traveling between the nozzle and the suction nozzle is faster than the speed of sound in air.

[0099] Yet another aspect of the present description relates to an apparatus for producing a laminar flow. The apparatus comprises: a pump; and a nozzle, the nozzle comprising a side wall defining a gas communication channel, the gas communication channel having an input port and an output port, the input port being coupled to the pump, wherein the side wall has a side opening that couples the gas communication channel to a proximate area outside the nozzle. In some embodiments, the apparatus further comprises a flow splitter surrounded by the gas communication channel, such that the flow splitter divides the gas communication channel into sub-channels. In some embodiments, the side opening is configured to divide a gaseous flow from the pump into a first portion that flows toward the output port and a second portion that flows into the proximate area through the side opening. In some embodiments, the side opening and the side wall are configured such that the second portion of the gaseous flow forms a Coanda flow that travels along an outer surface of the side wall toward the output port.

[0100] Another aspect of the present description relates to an apparatus for producing a particle shield in a lithography system. The apparatus includes: a pump; and a nozzle coupled to the pump, the nozzle including a main outlet, a side outlet, and a side splitter, wherein the side splitter is configured to split a gaseous flow from the pump into a first portion flowing toward the main outlet and a second portion flowing toward the side outlet. In some embodiments, the first portion of the gaseous flow forms a laminar flow after leaving the main outlet, thereby forming a particle shield. In some embodiments, the second portion of the gaseous flow forms a Coanda flow along an outer surface of the nozzle after leaving the side outlet. In some embodiments, the particle shield has a thickness of less than 1 mm, the thickness being defined by a full width at half maximum (FWHM) of a flow velocity distribution of the particle shield. In some embodiments, the ratio of the velocity of the gaseous flow after flowing through the nozzle to the velocity before flowing through the nozzle is at least 6:1.

[0101] Yet another aspect of the present description relates to an apparatus for generating at least one particle shield during a photolithography process. The apparatus includes: a first component; and a second component, wherein the first component and the second component are operable to form a first particle shield of the at least one particle shield for blocking particles from contacting an adjacent surface of an object, wherein the first component and the second component are located on the same side of the object, and wherein the first particle shield includes a thermal gradient driving force generated by a temperature difference between the first component and the second component. In some embodiments, the apparatus further includes a third component and a fourth component, wherein the third component and the fourth component are operable to form a second particle shield of the at least one particle shield for blocking particles from contacting an adjacent surface of an object, and wherein the second particle shield is a gaseous shield.

[0102] One aspect of the present disclosure relates to a lithography system, comprising: a radiation source configured to generate electromagnetic radiation; a photomask; an incident channel located between the radiation source and the photomask and used to cause the electromagnetic radiation to travel toward the photomask; a first nozzle configured to generate a first particle shield between the photomask and an outlet port of the incident channel; and a second nozzle configured to generate a second particle shield within the incident channel.

[0103] In an embodiment of the present disclosure, the first nozzle is of a first type, and the second nozzle is of a second type different from the first type.

[0104] In an embodiment of the present disclosure, the second particle shield includes a gas flow having a velocity greater than that of the first particle shield.

[0105] In an embodiment of the present disclosure, the second particle shielding body has a thickness smaller than that of the first particle shielding body.

[0106] In an embodiment of the present disclosure, the first particle shielding body is substantially parallel to the photomask, and the second particle shielding body is inclined relative to the photomask.

[0107] In an embodiment of the present disclosure, the photomask is a photomask without a pellicle.

[0108] In an embodiment of the present disclosure, the photolithography system further includes: a third nozzle configured to generate a third particle shielding body in the incident channel.

[0109] In an embodiment of the present disclosure, the second particle shielding body is close to the photomask and the third particle shielding body is far from the photomask, the second particle shielding body is inclined at a first angle relative to the photomask, and the third particle shielding body is inclined at a second angle greater than the first angle relative to the photomask.

[0110] In an embodiment of the present disclosure, the radiation source is an extreme ultraviolet radiation source.

[0111] In an embodiment of the present disclosure, the photolithography system further includes: a mask shielding blade located between the photomask and the incident channel, wherein the first particle shielding body is located between the photomask and the mask shielding blade.

[0112] Another aspect of the present disclosure relates to a lithography system, comprising: an extreme ultraviolet radiation source configured to generate extreme ultraviolet radiation; an extreme ultraviolet mask; a first type of nozzle, close to the extreme ultraviolet mask; and a plurality of second type of nozzles, close to the extreme ultraviolet radiation source, the second type of nozzles being different from the first type of nozzles, wherein the first type of nozzles and the second type of nozzles are configured to generate a particle shield in a propagation path of the extreme ultraviolet radiation.

[0113] In an embodiment of the present disclosure, the photolithography system further comprises: a plurality of suction nozzles configured to produce the particle shielding body in pair with the second type nozzles.

[0114] In an embodiment of the present disclosure, among the particle shielding bodies generated by the second type of nozzle, at least one particle shielding body is inclined at an angle relative to other particle shielding bodies.

[0115] In an embodiment of the present disclosure, the particle shielding body produced by the second type of nozzle has a higher gaseous flow velocity than the particle shielding body produced by the first type of nozzle.

[0116] In an embodiment of the present disclosure, the particle shielding body produced by the second type of nozzle has a larger particle size than the particle shielding body produced by the first type of nozzle.

[0117] In an embodiment of the present disclosure, the total number of the second type nozzles is not less than three.

[0118] Another aspect of the present disclosure relates to an apparatus for generating laminar flow in a lithography system, comprising: a pump; and a nozzle, the nozzle comprising a side wall and a splitter, the side wall defining a gas communication channel having an input port and an output port, the splitter dividing the gas communication channel into two sub-channels, wherein the splitter protrudes out of the output port.

[0119] In an embodiment of the present disclosure, a portion of the flow splitter protruding from the output port has a side wall surface, and the side wall surface is configured to merge the two gaseous flows flowing out of the two sub-channels into the laminar flow.

[0120] In an embodiment of the present disclosure, the flow divider has a central portion that is thicker than two end portions.

[0121] In an embodiment of the present disclosure, the laminar flow has a supersonic gaseous flow velocity.

[0122] The features of several embodiments are summarized above so that those skilled in the art can better understand the various aspects of the present disclosure. Those skilled in the art will appreciate that they can easily use the present disclosure as a basis for designing or modifying other processes and structures to implement the same purposes and / or achieve the same advantages as the embodiments described herein. Those skilled in the art will also recognize that these equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they can make various changes, substitutions, and modifications thereto without departing from the spirit and scope of the present disclosure.

Claims

1. A photolithography system, characterized in that: include: a radiation source configured to generate electromagnetic radiation; Photomask; an incident channel, located between the radiation source and the photomask, for causing the electromagnetic radiation to travel toward the photomask; a first nozzle configured to generate a first particle shield between the photomask and an outlet port of the incident channel; as well as a second nozzle configured to generate a second particle shield within the incident channel, wherein the second nozzle comprises a side wall and a flow divider, the side wall defining a gas communication channel having an input port and an output port, the flow divider dividing the gas communication channel into two sub-channels, wherein the diverter protrudes out of the output port, wherein the flow splitter comprises a first end portion proximate to the input port, A portion of the side wall adjacent to the input port has an inner surface parallel to a surface of the first end portion.

2. The lithography system according to claim 1, characterized in that: The first nozzle is of a first type, and the second nozzle is of a second type different from the first type.

3. The photolithography system according to claim 1, characterized in that: The second particle shield includes a gas flow with a velocity greater than that of the first particle shield.

4. The photolithography system according to claim 1, characterized in that: The second particle shielding body has a thickness smaller than that of the first particle shielding body.

5. The photolithography system according to claim 1, characterized in that: The first particle shielding body is substantially parallel to the photomask, and the second particle shielding body is inclined relative to the photomask.

6. The photolithography system according to claim 1, characterized in that: The photomask is a photomask without a pellicle.

7. The photolithography system according to claim 1, characterized in that: Also includes: The third nozzle is configured to generate a third particle shield in the incident channel.

8. The photolithography system according to claim 7, characterized in that: The second particle shielding body is close to the photomask and the third particle shielding body is far from the photomask, the second particle shielding body is inclined at a first angle relative to the photomask, and the third particle shielding body is inclined at a second angle greater than the first angle relative to the photomask.

9. The photolithography system according to claim 1, characterized in that: The radiation source is an extreme ultraviolet radiation source.

10. The photolithography system according to claim 1, characterized in that: Also includes: The mask shielding blade is located between the photomask and the incident channel, wherein the first particle shielding body is located between the photomask and the mask shielding blade.

11. A photolithography system, characterized in that: include: an extreme ultraviolet radiation source configured to generate extreme ultraviolet radiation; Extreme ultraviolet masks; A first type of nozzle, close to the extreme ultraviolet mask; as well as a plurality of second type nozzles, adjacent to the extreme ultraviolet radiation source, the second type nozzles being different from the first type nozzles, wherein the first type of nozzle and the second type of nozzle are configured to generate a particle shield in the propagation path of the extreme ultraviolet radiation, wherein the second type nozzle comprises a side wall and a flow divider, the side wall defining a gas communication channel having an input port and an output port, the flow divider dividing the gas communication channel into two sub-channels, wherein the diverter protrudes out of the output port, wherein the flow splitter comprises a first end portion proximate to the input port, A portion of the side wall adjacent to the input port has an inner surface parallel to a surface of the first end portion.

12. The photolithography system according to claim 11, characterized in that: Also includes: A plurality of suction nozzles are configured to produce the particle shield in pair with the second type of nozzles.

13. The photolithography system according to claim 11, characterized in that: Among the particle shielding bodies generated by the second type of nozzle, at least one particle shielding body is inclined at an angle relative to other particle shielding bodies.

14. The photolithography system according to claim 11, characterized in that: The particle shield produced by the second type of nozzle has a higher gaseous flow velocity than the particle shield produced by the first type of nozzle.

15. The photolithography system according to claim 11, characterized in that: The particle shielding body produced by the second type of nozzle has a larger particle size than the particle shielding body produced by the first type of nozzle.

16. The photolithography system according to claim 11, characterized in that: The total number of the second type nozzles is not less than three.

17. An apparatus for generating laminar flow in a photolithography system, characterized in that include: Pumps; as well as a nozzle comprising a side wall defining a gas communication channel having an input port and an output port, and a flow divider dividing the gas communication channel into two sub-channels, wherein the diverter protrudes out of the output port, wherein the flow splitter comprises a first end portion proximate to the input port, A portion of the side wall adjacent to the input port has an inner surface parallel to a surface of the first end portion.

18. The device according to claim 17, characterized in that The portion of the flow splitter protruding from the output port has a side wall surface, and the side wall surface is configured to merge the two gaseous flows flowing out of the two sub-channels into the laminar flow.

19. The device according to claim 17, characterized in that The flow divider has a central portion that is thicker than two end portions.

20. The device according to claim 17, characterized in that The laminar flow has a supersonic gas flow velocity.

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