Lithography system and reticle structure and manufacturing method thereof

Abstract

A lithography system and a reticle structure and a manufacturing method thereof, wherein the reticle structure comprises a reticle having a patterned feature and a first boundary portion surrounding the patterned feature. The reticle structure comprises a film having a middle portion and a second boundary portion surrounding the middle portion. The reticle structure comprises a frame disposed between the film and the reticle to mount the film on the patterned feature of the reticle. The frame establishes a closed space between the reticle and the film and surrounds the patterned feature of the reticle. The frame comprises a plurality of holes, and the plurality of holes produce a critical percentage of openings in the frame to maintain a balanced pressure difference between the closed space and the outside of the closed space below a critical pressure.

Description

Technical Field

[0001] The present disclosure relates to a lithography system and a reticle structure and a manufacturing method thereof. Background Art

[0002] During integrated circuit (IC) design, many layout patterns of the integrated circuit are generated for different steps of the integrated circuit manufacturing process. The layout pattern contains geometric shapes corresponding to the structures to be manufactured on the substrate. The layout pattern can be a pattern on a mask, which is projected (e.g., imaged) by a radiation source onto a photoresist layer on the substrate to build the integrated circuit. The lithography process transfers the pattern of the mask to the photoresist layer of the substrate so that etching, implantation or other steps are only applied to predetermined areas of the substrate. An extreme ultraviolet (EUV) radiation source can be used to expose the photoresist layer of the substrate to transfer the pattern of the mask to the photoresist layer. Summary of the invention

[0003] According to some embodiments of the present disclosure, a lithography system is provided, comprising: a reticle structure and an exposure device. The reticle structure comprises: a reticle, a film and a frame. The reticle has a plurality of patterned features. The frame is disposed between the film and the reticle, and is used to mount the film on the patterned features of the reticle, wherein the frame surrounds the patterned features and creates a closed space between the reticle and the film, wherein the frame comprises a plurality of holes, and the number of the holes is greater than a critical number of the holes, so as to maintain the equilibrium pressure difference between the closed space and the outside of the closed space at a critical pressure. The exposure device comprises a radiation source for emitting a radiation beam to reflect and / or project the patterned features of the reticle onto a substrate. The exposure device further comprises one or more reflectors for guiding the reflected and / or projected patterned features onto the substrate.

[0004] According to some embodiments of the present disclosure, a reticle structure is provided, comprising: a reticle, a film, and a frame. The reticle has a plurality of patterned features and a first boundary portion surrounding the patterned features. The film has a middle portion and a second boundary portion surrounding the middle portion. The frame is disposed between the film and the reticle and is used to mount the film on the patterned features of the reticle, wherein the frame forms a closed space between the reticle and the film and surrounds the patterned features of the reticle, wherein the frame comprises a plurality of holes, and wherein the holes produce a critical percentage of openings in the frame to keep the equilibrium pressure difference between the closed space and the outside of the closed space below a critical pressure.

[0005] According to some embodiments of the present disclosure, a method is provided, comprising: mounting a film on a frame, wherein the film comprises a middle portion and a boundary portion surrounding the middle portion; connecting a frame having a plurality of holes to the boundary portion of the film from a first side through a first adhesive layer, wherein the frame surrounds the middle portion of the film, and wherein deep ultraviolet light or extreme ultraviolet light radiation can penetrate the middle portion of the film; connecting a second adhesive layer to a second side of the frame opposite to the first side of the frame, wherein the frame is used to attach to a reticle via the second adhesive layer to create an enclosed space between the film, the reticle, and the frame; and providing a critical percentage of openings in the frame through the holes, wherein the critical percentage of openings maintains an equilibrium pressure difference below a critical pressure in a volume between an interior of the enclosed space and an exterior of the enclosed space. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The present disclosure can be best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, in accordance with standard practice in the industry, various features are not drawn to scale and are used for illustration purposes only. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

[0007] Figure 1 A schematic diagram of an extreme ultraviolet lithography system with a laser produced plasma (LPP) extreme ultraviolet (EUV) radiation source according to some embodiments of the present disclosure is shown;

[0008] Figure 2 A schematic diagram of an EUV lithography exposure tool according to some embodiments of the present disclosure is shown;

[0009] Figure 3A and Figure 3B A reflective reticle structure according to some embodiments of the present disclosure and a cross-sectional view of projecting the reflective reticle structure onto a semiconductor device are illustrated;

[0010] Figure 4 Drawing a film with a boundary;

[0011] Figure 5A , Figure 5B and Figure 5C A reticle structure having a protective film structure on the reticle according to some embodiments of the present disclosure is shown, wherein the protective film structure has a film mounted on a frame;

[0012] Figure 6 A graph showing the relationship between the pressure difference between the inside of a reticle structure and the outside of the reticle structure and the number of holes in a frame of the reticle structure according to some embodiments of the present disclosure;

[0013] Figure 7A control system for determining a critical number of holes on a frame of a reticle structure according to some embodiments of the present disclosure is illustrated;

[0014] Fig. 8A and Figure 8B An apparatus for determining a critical number of holes on a frame of a reticle structure according to some embodiments of the present disclosure is illustrated;

[0015] Fig.9A and Fig. 9B A flow chart is shown of a process for determining a critical number of holes of a reticle structure and a process for providing a protective film structure according to some embodiments of the present disclosure.

[0016]

Explanation of symbols

[0017] 10,210: Semiconductor substrate

[0018] 15: Photoresist layer

[0019] 23: Plasma plume

[0020] 30: Substrate

[0021] 34: Semiconductor components

[0022] 35: Multilayer

[0023] 37: Silicon layer

[0024] 39: Molybdenum layer

[0025] 40: Overlay

[0026] 45: Absorption layer

[0027] 50,50': Radiation beam

[0028] 55: Patterned features

[0029] 60: Back coating

[0030] 65: Film

[0031] 70: Protective film structure

[0032] 75,504: Framework

[0033] 80: Reticle

[0034] 85: Droplet Catcher

[0035] 100: Extreme ultraviolet radiation source

[0036] 105: Chamber

[0037] 110: Collector Mirror

[0038] 115: Droplet Generator

[0039] 117: Nozzle

[0040] 200: Exposure device

[0041] 205a, 205b, 205d, 205e: Optical device

[0042] 205c: Reflective Mask

[0043] 206,706: Vacuum pressure controller

[0044] 208,209: Pressure sensor

[0045] 300: Excitation laser source

[0046] 302: Line

[0047] 310: Laser generator

[0048] 320: Laser-guided optics

[0049] 330: Focusing device

[0050] 350: Reticle Structure

[0051] 360: Stand

[0052] 365,712: Bench controller

[0053] 402: Boundary Section

[0054] 410: Width

[0055] 412: Length

[0056] 505: Air filter

[0057] 506: Adhesive

[0058] 507: Boundary Layer

[0059] 510: Square hole

[0060] 520: Round hole

[0061] 530,530A,530B: Slit hole

[0062] 555: Enclosed Space

[0063] 602,604: coordinates

[0064] 610: Graph

[0065] 612,614,616,618: points

[0066] 700: System

[0067] 704: Extreme Ultraviolet Light Exposure Controller

[0068] 730: Analyzer module

[0069] 740: Main Controller

[0070] 800: Computer Systems

[0071] 801: Computer

[0072] 802: Keyboard

[0073] 803: Mouse

[0074] 804: Monitor

[0075] 805: CD player

[0076] 806: Disk drive

[0077] 811: Processor

[0078] 812: Read-only memory

[0079] 813: Random Access Memory

[0080] 814: Hard disk

[0081] 815: Bus

[0082] 821: CD

[0083] 822: Disk

[0084] 900,950: Process

[0085] S902, S904, S906, S908, S912, S914, S916, S918: Operation

[0086] 5A-5A, 5B-5B: Section cutting line

[0087] A: Angle

[0088] BF: Base Floor

[0089] DMP1, DMP2: Damper

[0090] DP: Target Droplet

[0091] LR0,LR1,LR2: Laser beam

[0092] MF: Main Floor

[0093] PP1,PP2: base plate

[0094] ZE: Excitation Zone DETAILED DESCRIPTION

[0095] The following disclosure provides many different embodiments or examples for realizing the different features of the present disclosure. The following describes specific embodiments of components and configurations to simplify the present disclosure. Of course, these are only embodiments and are not intended to be limiting. For example, in the following description, forming a first feature on or above a second feature may include an embodiment in which the first feature and the second feature are formed in direct contact, and may also include an embodiment in which additional features are 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 repeat reference numbers and / or text in various embodiments. This repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or configurations discussed.

[0096] Furthermore, spatially relative terms (e.g., "below," "below," "below," "above," "above," and other related terms) are used herein to simply describe the relationship of an element or feature as shown in the figure to another element or feature. When in use or operation, these spatially relative terms cover different rotations of the device in addition to the rotations shown in the figures. Furthermore, these devices can be rotated (rotated 90 degrees or other angles), and the spatially relative descriptors used herein can be interpreted accordingly. In addition, the term "made of..." can mean "comprising" or "consisting of..." In the present disclosure, the phrase "one of A, B, and C" means "A, B and / or C" (A, B, C, A and B, A and C, B and C, or A, B and C), and does not mean one element from A, one element from B, and one element from C unless otherwise specified.

[0097] The protective film is a transparent film stretched over a frame that is attached to one side of the mask with an adhesive to protect the mask from damage, dust, and / or moisture. Therefore, it is desirable for the protective film to have high transparency to the radiation source of the lithography process. In EUV lithography, it is desirable for the protective film to have high transparency in the EUV wavelength range and high durability.

[0098] When the reticle is covered with a protective film, the particles are located on the protective film instead of the reticle, so that when the reticle is imaged on the substrate, the particles not in the plane of the reticle will not produce a focused image on the substrate. The protective film is a material layer that is permeable to the ultraviolet radiation source of the lithography process (for example, a material layer that is permeable to the deep ultraviolet or extreme ultraviolet radiation source), and its thickness is about 25 nanometers (nm) to about 125 nanometers. In some embodiments, the protective film is made of silicon carbide (SiC), polycrystalline silicon, silicon nitride or graphene. In some embodiments, when the protective film is placed (for example, installed) on the top of the reticle, the protective film is placed on the top of multiple studs or fixtures, and a distance of about 2 mm to about 5 mm is formed between the reticle and the protective film. Therefore, in some embodiments, the distance between the reticle and the protective film will produce one or more openings, and dust particles can enter the enclosed space between the reticle and the protective film. In some embodiments, a protective film is attached to a mounting fixture, and the mounting fixture is attached above a reticle having a plurality of studs (e.g., four studs at the four corners of the reticle). An opening is created between the protective film and the reticle where no studs are present. Therefore, particles can enter the enclosed space between the protective film and the reticle from the opening. Alternatively, the distance between the reticle and the protective film can be sealed, and the distance between the reticle and the protective film does not create an opening, so that no dust particles can enter the space between the reticle and the protective film.

[0099] In some embodiments, the exposure device (e.g., exposure system) can perform ultraviolet lithography under vacuum. Therefore, when the opening between the reticle and the protective film is sealed at atmospheric pressure, a closed space with air captured at atmospheric pressure can be generated between the reticle and the protective film, and the protective film can be broken when the reticle structure (i.e., the combination of the reticle and the installed protective film) is placed in the exposure device under vacuum. In addition, if the opening between the reticle and the protective film is sealed in a vacuum environment, when the reticle structure is transferred to the outside of the exposure device and placed under atmospheric pressure, the protective film may also break due to the difference between the external atmospheric pressure and the vacuum in the closed space. In addition, in some embodiments, the distance between the protective film and the reticle is neither completely sealed nor substantially open, but has some openings in the frame of the protective film. It is desirable to form some openings (e.g., holes) in a mounting fixture (e.g., frame) between the protective film and the reticle to support the protective film on the reticle. In the frame, the openings are distributed as unconnected individual openings, and each opening has a limited size so that when the protective film is mounted on the reticle, dust particles are not easy to enter through the holes between the reticle and the protective film. In addition, the holes of the mounting fixture allow the pressure exchange between the closed space formed between the reticle and the protective film and the external pressure, so that when the mask with the protective film is transferred to the exposure device and is in a vacuum state environment or transferred out of the exposure device for storage under atmospheric pressure, the protective film will not break. In some embodiments, for deep ultraviolet light lithography (e.g., for 193 nanometer lithography), a protective film structure with a film attached to the frame is used. The frame has some openings for allowing gas to circulate between the closed space surrounded by the frame and enclosed by the protective film and the reticle and the outside of the enclosed space. In some embodiments, due to the high energy of extreme ultraviolet radiation, the extreme ultraviolet exposure device is in a higher vacuum environment than the deep ultraviolet exposure device. Therefore, the protective film structure used in the deep ultraviolet lithography system may be broken in the extreme ultraviolet lithography system, and it is necessary to increase the opening in the frame so that a faster pressure equalization can occur between the enclosed space and the outside of the enclosed space. In some embodiments, the pressure inside the deep ultraviolet exposure device or the extreme ultraviolet exposure device is between about 3 and about 5 Pascals.

[0100] Figure 1 A schematic diagram of an EUV lithography system with a laser produced plasma (LPP) EUV radiation source according to some embodiments of the present disclosure is shown. The EUV lithography system includes an EUV radiation source 100 (EUV light source) for generating EUV radiation, an exposure device 200 (e.g., an exposure machine), and an excitation laser source 300. Figure 1In some embodiments, the extreme ultraviolet radiation source 100 and the exposure device 200 are installed on the main floor MF of the clean room, and the excitation laser source 300 is installed in the base floor BF located below the main floor. Each of the extreme ultraviolet radiation source 100 and the exposure device 200 is placed on the base plates PP1 and PP2 via dampers DMP1 and DMP2, respectively. The extreme ultraviolet radiation source 100 and the exposure device 200 are coupled to each other through a coupling mechanism, and the coupling mechanism may include a focusing unit. In some embodiments, the lithography system includes the extreme ultraviolet radiation source 100 and the exposure device 200.

[0101] The lithography system is designed to expose a photoresist layer through extreme ultraviolet light (also interchangeably referred to as EUV radiation herein). The photoresist layer is a material that is sensitive to EUV light. The EUV lithography system uses an EUV radiation source 100 to generate EUV light (e.g., EUV light having a wavelength ranging from about 1 nanometer to about 50 nanometers). In a specific embodiment, the EUV radiation source 100 generates EUV light having a wavelength centered at about 13.5 nanometers. In the present embodiment, the EUV radiation source 100 uses the mechanism of laser-generated plasma to generate EUV radiation.

[0102] The exposure device 200 includes various reflective optical elements (e.g., convex mirrors / concave mirrors / plane mirrors), a mask holding mechanism including a mask stage, and a wafer holding mechanism (e.g., a substrate holding mechanism). The EUV radiation generated by the EUV radiation source 100 is guided by the reflective optical elements to a mask fixed on the mask stage. In some embodiments, the mask stage includes an electrostatic chuck (e-cuck) for fixing the mask. Since gas molecules absorb EUV light, the lithography system used for EUV lithography patterning needs to be maintained in a vacuum or low-pressure environment to avoid loss of EUV light intensity. Please refer to the description of the exposure device 200 in more detail. Figure 2. In some embodiments, the reticle is transferred to exposure device 200. As described above, exposure device 200 is maintained in a vacuum environment, and the reticle is mounted on a substrate, wherein a photoresist layer is disposed on the substrate. The reticle has a protective film mounted on the reticle. After the reticle with the protective film is transferred to exposure device 200, the air pressure in the enclosed space between the reticle and the protective film is balanced with the vacuum environment of exposure device 200 through the holes in the mounting fixture (frame). The optical element guides the extreme ultraviolet radiation generated by extreme ultraviolet radiation source 100 to project the mask onto the photoresist layer of the substrate. In some embodiments, after exposing the mask on the photoresist layer of the substrate, the reticle with the protective film is transferred outside of exposure device 200. After the reticle with the protective film is transferred outside of exposure device 200, the air pressure in the enclosed space between the reticle and the protective film is balanced with the atmospheric pressure outside of exposure device 200 through the holes in the mounting fixture.

[0103] In the present disclosure, the terms mask, photomask, and reticle are used interchangeably. In addition, the terms photoresist and photoresist are used interchangeably. In some embodiments, the mask is a reflective mask. In some embodiments, the mask includes a substrate having a suitable material (e.g., a low thermal expansion material or fused quartz). In different embodiments, the material includes silicon dioxide (SiO2) doped with titanium dioxide (TiO2) or other suitable materials with low thermal expansion. The mask includes multiple reflective layers (ML) deposited on the substrate. The multiple reflective layers include multiple film pairs (e.g., molybdenum / silicon (Mo / Si) film pairs (e.g., a molybdenum layer above or below a silicon layer in each film pair)). Alternatively, the multiple reflective layers may include molybdenum / beryllium (Mo / Be) film pairs, or other suitable materials that can be used to highly reflect extreme ultraviolet light. The mask may further include a capping layer (e.g., ruthenium (Ru)) disposed on the multiple reflective layers for protection. The mask also includes an absorber layer (e.g., a tantalum boron nitride (TaBN) layer) deposited on the plurality of reflective layers. The absorber layer is patterned to define a layer of an integrated circuit (IC). Alternatively, another reflective layer may be deposited on the plurality of reflective layers and patterned to define a layer of an integrated circuit, thereby forming an EUV phase shift mask. For a description of this mask, please refer to Figure 3A .

[0104] The exposure apparatus 200 includes a projection optical module for imaging the pattern of the mask onto a semiconductor substrate, wherein the semiconductor substrate is coated with a photoresist and fixed on a substrate stage of the exposure apparatus 200. The projection optical module generally includes a reflective optical device. The projection optical module collects extreme ultraviolet radiation (EUV light) guided by the mask (the mask having an image of the pattern defined on the mask) to form an image on the photoresist.

[0105] In various embodiments of the present disclosure, the semiconductor substrate is a semiconductor wafer (e.g., a silicon wafer or other type of wafer to be patterned). In embodiments of the present disclosure, the semiconductor substrate is coated with a photoresist layer that is sensitive to extreme ultraviolet light. The various elements described above are integrated together to perform a lithography exposure process. The lithography system may further include other modules or be integrated (or coupled) with other modules.

[0106] like Figure 1 As shown, the extreme ultraviolet radiation source 100 includes a droplet generator 115 surrounded by a chamber 105 and a laser-generated plasma collector mirror 110. The droplet generator 115 generates a plurality of target droplets (also referred to as droplets) DP, which are supplied to the chamber 105 through a nozzle 117. In some embodiments, the target droplets DP are tin (Sn), lithium (Li), or an alloy of tin (Sn) and lithium (Li). In some embodiments, each of the target droplets DP has a diameter in the range of about 10 micrometers (μm) to about 100 micrometers. For example, in one embodiment, the target droplets DP are tin droplets, each of which has a diameter of about 10 micrometers, about 25 micrometers, about 50 micrometers, or any diameter between these values. In some embodiments, the target droplets DP are supplied through the nozzle 117 at a velocity ranging from about 50 droplets per second (i.e., a jetting frequency of about 50 Hertz (Hz)) to about 50,000 droplets per second (i.e., a jetting frequency of about 50 kHz). For example, in one embodiment, the target droplets DP are supplied at a jetting frequency of about 50 Hz, about 100 Hz, about 500 Hz, about 1 kHz, about 10 kHz, about 25 kHz, about 50 kHz, or any jetting frequency in between these frequencies. In various embodiments, the target droplets DP are ejected through the nozzle 117 into the excitation region ZE (e.g., the target droplet location) at a velocity in a range from about 10 meters per second (10 m / s) to about 100 m / s. For example, in one embodiment, the target droplets DP have a velocity of about 10 m / s, about 25 m / s, about 50 m / s, about 75 m / s, about 100 m / s, or any velocity in between these velocities.

[0107] The excitation laser beam LR2 generated by the excitation laser source 300 is a pulsed beam. The laser pulses of the laser beam LR2 are generated by the excitation laser source 300. The excitation laser source 300 may include a laser generator (also referred to as a laser source) 310, a laser guiding optical device 320, and a focusing device 330. In some embodiments, the laser generator 310 includes a carbon dioxide (CO2) or a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser source having a wavelength in the infrared region of the electromagnetic spectrum. For example, in one embodiment, the laser source 310 has a wavelength of 9.4 microns or 10.6 microns. The laser guiding optical device 320 guides the laser beam LR0 generated by the excitation laser source 300, and the focusing device 330 focuses the laser beam LR0 into the excitation laser beam LR2 introduced into the extreme ultraviolet radiation source 100. In some embodiments, in addition to the carbon dioxide or Nd-doped YAG laser, the laser beam LR2 is also generated by a gas laser, wherein the gas laser includes an excimer gas discharge laser, a helium-neon laser, a nitrogen laser, a transversely excited atmospheric (TEA) laser, an argon ion laser, a copper vapor laser, a krypton fluoride laser; or an argon fluoride laser or a solid-state laser (including a neodymium: glass laser, an ytterbium-doped glass or ceramic laser, or a ruby ​​laser). In some embodiments, the excitation laser source 300 also generates a non-ionizing laser beam LR1, and the focusing device 330 also focuses the laser beam LR1.

[0108] In some embodiments, the excitation laser beam LR2 comprises a preheating laser pulse and a main laser pulse. In such embodiments, the preheating laser pulse (interchangeably referred to herein as a "pre-pulse") is used to heat (or preheat) a given target droplet to produce a low-density target plume having a plurality of smaller droplets, which are subsequently heated (or reheated) by the main laser pulse (main pulse), resulting in increased extreme ultraviolet light emission compared to when no preheating laser pulse is used.

[0109] In various embodiments, the preheating laser pulse has a spot size of about 100 microns or less, and the main laser pulse has a spot size in the range of about 150 microns to about 300 microns. In some embodiments, the pulse duration of the preheating laser and the main laser pulse is in the range of about 10 nanoseconds (ns) to about 50 nanoseconds, and the pulse frequency is in the range of about 1 kHz to about 100 kHz. In various embodiments, the average power of the preheating laser and the main laser is in the range from about 1 kilowatt (kW) to about 50 kW. In one embodiment, the pulse frequency of the excitation laser beam LR2 matches the ejection frequency of the target droplet DP.

[0110] The laser beam LR2 is guided through a window mirror (or lens) into the excitation region ZE. The window mirror is made of a suitable material that is substantially transparent to the laser beam. The generation of the laser pulse is synchronized with the target droplet DP ejected through the nozzle 117. As the target droplet moves through the excitation region, the pre-pulse heats the target droplet and transforms it into a low-density target plume. The delay between the pre-pulse and the main pulse is controlled to allow the target plume to form and expand to an optimal size and geometry. In different embodiments, the pre-pulse and the main pulse have the same pulse duration and peak power. When the main pulse heats the target plume, a high-temperature plasma is generated. The plasma emits extreme ultraviolet radiation that is collected by the collector mirror 110. The collector mirror 110 (extreme ultraviolet light collector mirror) further reflects and focuses the extreme ultraviolet radiation so that the extreme ultraviolet radiation can perform a lithography exposure process in the exposure device 200. The target droplet DP that does not interact with the laser pulse is captured by the droplet catcher 85.

[0111] One method of synchronizing the generation of pulses (one or both of the pre-pulse and the main pulse) from the excitation laser with the arrival of the target droplet at the excitation region is to detect the passage of the target droplet at a given position and use it as a signal to trigger the excitation pulse (or pre-pulse). In this method, for example, if the passage time of the target droplet is t o The time when the extreme ultraviolet radiation is generated (and detected) is represented by t rad It is represented by, and the distance between the position where the target droplet passes and the center of the excitation area is detected as d, and the velocity of the target droplet v dp The calculation of v dp =d / (t rad -t o ) formula (1). Since it is expected that the droplet generator 115 repeatedly supplies droplets at a fixed speed, once v is calculated dp , after detecting that the target droplet has passed a given position, the dpThe excitation pulse is triggered with a time delay of t to ensure that the excitation pulse arrives at the same time as the target droplet reaches the center of the excitation region. In some embodiments, because the passage of the target droplet is used to trigger the pre-pulse, the main pulse is triggered after a fixed delay after the pre-pulse. In some embodiments, if necessary, by periodically measuring t rad To periodically recalculate the target droplet velocity v dp value and resynchronizes the arrival of the target droplet with the generation of the pulse.

[0112] Figure 2 A schematic diagram of an EUV lithography exposure tool according to some embodiments of the present disclosure is shown. Figure 2 The EUV lithography exposure tool includes an exposure apparatus 200, which illustrates exposure of a photoresist-coated substrate (target semiconductor substrate 210) with a patterned beam of EUV light. Exposure apparatus 200 is an integrated circuit lithography tool (e.g., a stepper, an exposure machine, a stepper and exposure system, a direct write system, a device using a contact and / or proximity mask, etc.), which has one or more optical devices 205a, 205b, for example, for irradiating a patterned optical device (such as a reticle, such as a reflective mask 205c) with an EUV beam to produce a patterned beam, and has one or more reduced projection optical devices 205d, 205e to project the patterned beam onto the target semiconductor substrate 210. Mechanical elements (not shown) may be provided to produce controlled relative motion between the target semiconductor substrate 210 and the patterned optical device (e.g., reflective mask 205c). As further illustrated, Figure 2 The EUV lithography exposure tool further includes an EUV radiation source 100, which includes a plasma plume 23 in an excitation region ZE, and the plasma plume 23 emits EUV light in a chamber 105, and the EUV light is collected by a collector mirror 110 and reflected into an exposure device 200 to illuminate a target semiconductor substrate 210. In some embodiments, the pressure inside the exposure device 200 is sensed by a pressure sensor 208 inside the exposure device 200, and is controlled by a vacuum pressure controller 206 coupled to the exposure device 200.

[0113] As described above, since gas molecules absorb extreme ultraviolet light, the lithography system (e.g., exposure device 200) used for extreme ultraviolet lithography patterning needs to be maintained in a vacuum environment to avoid extreme ultraviolet light intensity loss. After the reticle with a protective film is transferred to exposure device 200, the air pressure in the enclosed space between the reticle and the protective film is balanced with the vacuum environment of exposure device 200 through the holes in the mounting fixture (frame), so that a vacuum is generated in the enclosed space between the reticle and the protective film. In some embodiments, after the mask is exposed on the photoresist layer of the substrate, the reticle with a protective film (reticle structure) is transferred outside of exposure device 200. After the reticle with a protective film is transferred outside of exposure device 200, the vacuum in the enclosed space between the reticle and the protective film is balanced with the atmospheric pressure outside of exposure device 200 through the holes in the mounting fixture, so that atmospheric pressure is generated in the enclosed space between the reticle and the protective film.

[0114] Figure 3A and Figure 3B A reflective reticle structure 350 (eg, a reticle system) according to some embodiments of the present disclosure and a cross-sectional view of the reflective reticle structure 350 projected onto a semiconductor device are shown. Figure 3A A cross-sectional view of a reflective reticle structure 350 including a reticle 80 (e.g., a reflective mask) is shown. As described above, the terms mask, light mask, and reticle may be used interchangeably. In some embodiments, reticle 80 is a reflective mask and is a part of reflective reticle structure 350. Reflective reticle structure 350 and Figure 2 The reflective mask 205c is consistent with the reflective mask 205c, and Figure 2 The exposure device 200 is used.

[0115] A reflective mask (e.g., a reticle 80) includes a substrate 30, a reflective multilayer 35 deposited on the substrate 30, a conductive back coating 60, a cover layer 40, and an absorption layer 45. In some embodiments, the material of the substrate 30 includes silicon dioxide (SiO2) doped with titanium dioxide (TiO2) or other suitable materials with low thermal expansion. In some embodiments, the substrate 30 includes fused quartz and has a thickness between about 6 mm and about 7 mm. In some embodiments, the multilayer 35 includes a plurality of film pairs (e.g., molybdenum / silicon (Mo / Si) film pairs) (e.g., a molybdenum layer 39 is provided above or below a silicon layer 37 in each film pair). In some embodiments, the multilayer 35 has 40 to 50 pairs of molybdenum layers 39 and silicon layers 37, and each molybdenum layer 39 has a thickness of 3 nanometers and each silicon layer 37 has a thickness of 4 nanometers. Therefore, in some embodiments, the multilayer 35 has a thickness between 280 nanometers and 350 nanometers. Alternatively, multilayer 35 may include a molybdenum / beryllium (Mo / Be) film pair, or other suitable materials to highly reflect extreme ultraviolet light. Capping layer 40 may include ruthenium (Ru) and may be disposed on multilayer 35 for protection and may have a thickness of 2.5 nanometers. In some embodiments, capping layer 40 may include silicon (Si) and may be disposed on multilayer 35 for protection and may have a thickness of 4 nanometers. In some embodiments, an absorption layer 45 including a tantalum boron nitride (TaBN) layer is deposited over multilayer 35 and capping layer 40. In some embodiments, absorption layer 45 is patterned with patterned features 55 to define a layout pattern for a layer of an integrated circuit. In some embodiments, backside coating 60 includes chromium nitride (CrN) or tantalum boride (TaB) and has a thickness of 20 nanometers to 100 nanometers. In some embodiments, another reflective layer may be deposited over multilayer 35 and patterned to define a layer of an integrated circuit, thereby forming an extreme ultraviolet phase shift reticle. In some embodiments, the absorption layer 45 comprises one or a combination of tantalum boron oxide (TaBO), tantalum boron nitride (TaBN), tantalum nitride oxide (TaNO), and tantalum nitride (TaN), and has a thickness between 50 nanometers and 70 nanometers. In some embodiments, the reflective reticle structure 350 further comprises a protective film structure 70, which is a mounting structure comprising a film 65 mounted on a frame 75. Figure 5A and Figure 5B The protective film structure 70 is described in .

[0116] Figure 3B Exposing a photoresist of a semiconductor device to radiation is shown according to some embodiments of the present disclosure. Figure 3B A semiconductor device 34 is shown, which includes a photoresist layer 15 disposed on a semiconductor substrate 10 . Figure 3BAlso shown is a radiation beam 50 originating from an EUV light source (e.g. Figure 1 The radiation beam 50 is directed to a reticle 80 (e.g., a reflective light mask), where the radiation beam 50' is reflected from the reflective light mask 80 and incident on the photoresist layer 15. The incident angle of the radiation beam 50' is an angle A defined relative to a line 302 perpendicular to the top surface of the semiconductor substrate 10. Figure 3B As shown, the incident radiation beam 50 and the reflected radiation beam 50' pass through the film 65 of the protective film structure 70. In some embodiments, Figure 2 The semiconductor substrate 10 consistent with the semiconductor substrate 210 is mounted on a stage 360 ​​, wherein the stage 360 ​​is coupled to and controlled by a stage controller 365 to move the semiconductor element 34 and expose different positions of the semiconductor element 34 .

[0117] Figure 4 A protective film 65 (eg, a transparent film) having a boundary portion 402 is depicted. Figure 4 The back side of the film 65 (facing the reticle) is shown with a boundary layer 507 disposed on the boundary portion 402 on the back side of the film 65. Figure 5A and Figure 5B As shown, the film 65 is attached to the frame 504 from the back, and the boundary layer 507 at the boundary portion 402 contacts the frame 504. As described above, the thickness of the film 65 is about 25 nanometers to about 125 nanometers, and the material of the film 65 is a material that is transparent to the ultraviolet radiation source (for example, a material that is transparent to the deep ultraviolet light or extreme ultraviolet light radiation source of the lithography process). In some embodiments, the width 410 of the film 65 is between about 50 mm and about 100 mm, and the length 412 of the film 65 is between about 100 mm and about 200 mm. Figure 4 Also shown is the Figure 5A and Figure 5B The cross-sectional cutting lines (also referred to as planes) 5A-5A and 5B-5B of the thin film 65 are shown in FIG. 5A-5A. In some embodiments, the boundary layer 507 disposed on the boundary portion 402 of the thin film 65 includes silicon (Si). In some embodiments, another layer (not shown) including one or more of the elements ruthenium (Ru), molybdenum (Mo), zirconium (Zr), boron (B), niobium (Nb), iridium (Ir), titanium (Ti), oxides of the elements, or oxynitrides of the elements is disposed on the thin film 65 on the opposite side of the boundary layer 507 for heat dissipation.

[0118] Figure 5A , Figure 5B and Figure 5CA reticle structure 350 is shown having a protective film structure 70 on a reticle 80 according to some embodiments of the present disclosure. The protective film structure 70 has a film 65 mounted on a frame 504. The frame 504 and Figure 3A The frame is consistent with 75. Figure 5B is through Figure 5A Cross-sectional view of plane (section cutting line) 5B-5B. Figure 5A and Figure 5B Film 65 is shown mounted to frame 504 at boundary portion 402 via boundary layer 507 and adhesive (also referred to as adhesive layer) 506 to produce protective film structure 70. Protective film structure 70 is mounted on reticle 80 via adhesive 506 (e.g., double-sided adhesive). In some embodiments, frame 504 surrounds a layout pattern (not shown) on top of reticle 80 and forms a closed space 555 between reticle 80 and film 65 on the layout pattern. In some embodiments, boundary layer 507 at boundary portion 402 on the back side of film 65 is attached to one side of frame 504 via adhesive 506. In some embodiments, the other side of frame 504 is attached to reticle 80 via adhesive 506 (e.g., double-sided adhesive). As shown in FIG. Figure 5AIn the embodiment shown, the frame 504 includes a plurality of holes having different shapes (e.g., square holes 510, slit holes 530, or circular holes 520). Therefore, air can enter and exit the enclosed space 555 via the square holes 510, the slit holes 530, and the circular holes 520. In some embodiments, the slit holes 530 are completely surrounded by the frame 504 or embedded in the frame 504. In some embodiments, one side of the slit holes 530 is formed by a protective film 65 or a reticle 80. In other embodiments, the top and bottom sides of the slit holes 530 are formed by a protective film 65 and a reticle 80. In some embodiments, the slit holes 530 have a height of about 0.5 mm to 2 mm and a length of about 1 mm to 10 mm. In some embodiments, the square holes 510 have sides of about 0.5 mm to 5 mm, and the circular holes 520 have a diameter of about 0.5 mm to 5 mm. In some embodiments, the thickness or diameter of the hole is constant. In other embodiments, the hole has a tapered shape toward the inside or outside of the protective film. In some embodiments, the hole is bent multiple times (e.g., crank shape) from the outside of the protective film to the inside of the protective film. In some embodiments, the total number of holes is between about 20 holes and about 200 holes on all sides. In some embodiments, the total opening area of ​​the hole is between about 6% and about 15% of the surface area of ​​the frame 504. In some embodiments, the total opening area at the four sides is substantially equal to each other. In some embodiments, the thickness of the frame 504 is the width of the boundary portion 402 and is between about 2 mm and 5 mm. As described, when the reticle structure 350 experiences a sudden pressure change, the square hole 510, the slit hole 530 and the circular hole 520 can prevent the rupture of the film 65. In some embodiments, the hole is a slit hole, a square hole or a circular hole. In some embodiments, the hole has the same diameter between 0.5 mm and 1 mm and is evenly distributed in the side of the frame.

[0119] In some embodiments, dust particles may enter through the square holes 510, the slit holes 530, or the circular holes 520. Therefore, an air filter may be disposed in one or more of the square holes 510, the slit holes 530, or the circular holes 520 to prevent dust particles from entering the enclosed space 555. Figure 5C and Figure 5ASimilarly, the difference is that the two slit holes (e.g., slit holes 530A and 530B) bounded by the reticle 80 have air filters 505 in the slit holes 530A and 530B to prevent particles from passing through the slit holes 530A and 530B. In some embodiments, the thickness of the frame 504 is increased, or the positions of the square holes 510, the slit holes 530, and the circular holes 520 are optimized to minimize the chance of particles entering the enclosed space 555. In some embodiments, the height of the enclosed space 555 is between about 2 mm and about 5 mm. In some embodiments, the protective film structure 70 is reusable, so the protective film structure 70 can be separated from the mask (e.g., reticle 80) and reused in another reticle structure. In some embodiments, the film 65 is reusable, so the film 65 can be separated from the protective film structure 70 and reused in another protective film structure.

[0120] Figure 6 A graph 610 is shown showing the relationship between pressure difference and number of holes according to some embodiments of the present disclosure, wherein coordinate 602 represents the pressure difference between the inside of enclosure 555 and the outside of enclosure 555 (this pressure difference varies between 0 and 10.0 (in Pascals)) and coordinate 604 represents the number of holes on the frame 504 of the reticle structure (this number of holes varies between 0 and 250 (e.g., holes of the same shape and size)). In some embodiments, the pressure difference between enclosure 555 and the outside of enclosure 555 is measured when the pressure between enclosure 555 and the outside of enclosure 555 is balanced. In some embodiments, graph 610 corresponds to Figure 3A As shown, when the number of holes at point 612 is about 150, the pressure difference between the inside and outside of the enclosed space 555 is less than about 3.5 Pascals (point 616), and when the number of holes at point 614 is about 200, the pressure difference between the inside and outside of the reticle structure is less than about 2.5 Pascals (point 618).

[0121] As noted, when the reticle structure is transferred from exposure device 200 to the atmospheric pressure outside of exposure device 200 and the pressure is balanced between enclosed space 555 and outside of enclosed space 555, the pressure between the inside and outside of enclosed space 555 is measured. Figure 6In some embodiments, when the reticle structure is transferred from the atmospheric pressure outside the exposure device 200 to the exposure device 200 and the pressure between the enclosed space 555 and the vacuum outside the enclosed space 555 is balanced, the pressure difference between the inside and outside of the enclosed space 555 is measured. In some embodiments, after a critical time, the pressures of the enclosed space 555 and the outside of the enclosed space 555 are equal. In some embodiments, the critical time is defined as between about 10 seconds and about 30 seconds. In some embodiments, Figure 2 The vacuum pressure controller 206 is coupled to the pressure sensor 208 inside the exposure device 200, and is also coupled to another pressure sensor 209 inside the closed space 555 of the reflective reticle structure 350 (which is consistent with the reflective mask 205c). Both or one of the pressure sensors 208 and 209 are coupled to the vacuum pressure controller 206 by wire or wirelessly. When the reflective reticle structure 350 is inside the exposure device, the vacuum pressure controller 206 determines the pressure difference between the closed space 555 and the outside of the closed space 555. In addition, when the reflective reticle structure 350 is at atmospheric pressure, the vacuum pressure controller 206 determines the pressure difference between the closed space 555 and the outside of the closed space 555.

[0122] Figure 7 A control system for determining a critical number of holes and / or a critical total area covered by holes on a frame 504 of a reticle structure according to some embodiments of the present disclosure is shown. System 700 includes an analyzer module 730 and a main controller 740 coupled to each other. System 700 also includes a vacuum pressure controller 706 coupled to analyzer module 730 via main controller 740. In some embodiments, analyzer module 730 receives a signal from vacuum pressure controller 706 in accordance with vacuum pressure controller 206. Figure 1 and Figure 2 When the reticle structure is placed inside the exposure device 200 and the pressure is balanced, the vacuum pressure controller 706 also receives the pressure inside the reticle structure 350 (e.g., atmospheric pressure). Figure 5A The vacuum pressure controller 706 also receives the pressure inside the reticle structure 350 when the reticle structure is placed outside the exposure device 200 and the pressure is balanced. The analyzer module 730 determines the pressure difference between the inside of the enclosed space 555 and the outside of the enclosed space 555. Based on the critical pressure difference between the inside of the enclosed space 555 and the outside of the enclosed space 555, the analyzer module 730 can determine the critical number of holes on the frame of the reticle structure 350 and / or the critical total area covered by the holes.

[0123] In some embodiments, the critical total area of ​​coverage between the inside of the enclosed space 555 and the outside of the enclosed space 555 and / or the holes on the frame is modified, and the equilibrium pressure difference between the inside of the enclosed space 555 and the outside of the enclosed space 555 is measured. In some embodiments, a graph (e.g., Figure 6 610). The critical number of holes is determined based on the critical pressure difference using the graph 610. In some embodiments, the number of holes includes the shape, size (e.g., length, width, or radius) of the holes, and the location of the holes (e.g., the height of the holes from the reticle 80). In some embodiments, the critical number of holes is determined based on the maximum acceptable (tolerable) pressure difference between the inside of the enclosed space 555 and the outside of the enclosed space 555.

[0124] In some embodiments, vacuum pressure controller 206 provides pressure inside exposure apparatus 200 and pressure inside enclosure 555. System 700 includes EUV light exposure controller 704, which is coupled to analyzer module 730 via main controller 740. EUV light exposure controller 704 controls the intensity of EUV radiation (e.g., Figure 3B The system 700 also includes a platform controller 712 coupled to the analyzer module 730 via a main controller 740. The platform controller 712 and Figure 3B The gantry controller 365 is consistent with the Figure 3B As shown, the platform controller 712 is used to move Figure 3B The semiconductor device 34 is formed by a lithography process and different locations of the semiconductor device 34 are exposed by the radiation beam 50 during the lithography process.

[0125] Fig. 8A and Figure 8B An apparatus for determining a critical number of holes on a frame 504 of a reticle structure 350 is shown according to some embodiments of the present disclosure. Fig. 8A is produced Figure 6 The computer system 800 may also determine Figure 3A The critical number of holes of the frame 504 of the reticle structure 350. The processes, methods and / or operations of all or part of the aforementioned embodiments can be implemented using computer hardware and computer programs executed thereon. In some embodiments, the computer system 800 provides the functions of the extreme ultraviolet light exposure controller 704, the analyzer module 730, the main controller 740, the platform controller 712 and the vacuum pressure controller 706. Fig. 8AIn the figure, the computer system 800 has a computer 801, which includes a CD-ROM (for example, a CD-ROM or a DVD-ROM) drive (also called an optical drive) 805 and a disk drive 806, a keyboard 802, a mouse 803 and a monitor 804.

[0126] Figure 8B The internal configuration of the computer system 800 is shown. Figure 8B In addition to the optical disc drive 805 and the disk drive 806, the computer 801 also has one or more processors 811 (e.g., microprocessor units (MPUs)), a read-only memory 812 (in which programs such as boot programs are stored), a random access memory (RAM) 813 (which is connected to the processor 811 and temporarily stores application program commands therein and provides a temporary storage area), a hard disk 814 (in which application programs, system programs, and data are stored), and a bus 815 (which connects the processor 811, the read-only memory 812, etc.). It should be understood that the computer 801 may include a network card (not shown) for providing a connection to a local area network (LAN).

[0127] In the aforementioned embodiment, the program for enabling the computer system 800 to determine the critical number of holes on the frame 504 of the reticle structure 350 may be stored in an optical disk 821 or a disk 822, which is inserted into the optical disk drive 805 or the disk drive 806 and transferred to the hard disk 814. Alternatively, the program may be transferred to the computer 801 via a network (not shown) and stored in the hard disk 814. When executed, the program is loaded into the random access memory 813. The program may be loaded from the optical disk 821 or the disk 822 or directly from the network. This program does not necessarily include, for example, an operating system (OS) or a third-party program to enable the computer 801 to perform the process for manufacturing a lithography mask for a semiconductor device in the aforementioned embodiment. This program may only include a command portion to call the appropriate function (module) in a controlled mode and obtain the desired result.

[0128] Fig.9A and Fig. 9B A flow chart of a process 900 for determining a critical number of holes in a reticle structure and a process 950 for providing a protective film structure according to some embodiments of the present disclosure is shown. The process 900 or a portion of the process 900 may be Figure 2 In some embodiments, process 900 or a portion of process 900 is performed by the above reference Fig. 8A and Figure 8BIn some embodiments, process 900 or a portion of process 900 is performed and / or controlled by computer system 800 as described above. Figure 7 The process includes operation S902, wherein a first protective film structure is determined from a plurality of protective film structures to construct a reticle structure (eg, Figure 3A and Figure 5A As shown in the figure, the reticle structure 350 includes a reticle 80 and a protective film structure 70 mounted on the reticle 80. Each of the plurality of protective film structures 70 includes Figure 5A The film 65 and frame 504 shown or Figure 3A Frame 75 is shown, which is disposed between reticle 80 and film 65 to mount film 65 on reticle 80. In some embodiments, frame 75 surrounds patterned features 55 of reticle 80. In some embodiments, frame 504 creates a closed space 555 between reticle 80 and film 65. In some embodiments, frame 504 of each reticle structure 70 in a plurality of reticle structures has a different number of holes. The frame of the first reticle structure has a first number of holes.

[0129] In operation S904, the pressure difference between the closed space 555 and the outside of the closed space 555 is measured. Figure 2 The pressure difference is measured after the exposure device 200 (of the embodiment of FIG. 1 ) is transferred to the outside of the exposure device 200 at atmospheric pressure. In some embodiments, the pressure difference is measured after the transfer of the reticle structure 350 and after a delay time (e.g., between 10 seconds and 30 seconds) (until the pressure difference is balanced, e.g., stabilized).

[0130] In operation S906, the above-mentioned determination and measurement steps are repeated repeatedly until the equilibrium pressure difference is less than the critical pressure. In each determination step, a different protective film structure is selected so that the different protective film structure has a frame with a greater number of holes. In some embodiments, the holes have a circular shape with a diameter of 2 mm. The frame of the first protective film structure has 100 holes, and in each interaction, the number of holes increases by 5% to 10% until the measured equilibrium pressure difference is less than the critical pressure of 3.5 Pascals. Figure 6 Graph 610 depicts equilibrium pressure difference with respect to the number of holes in the frame 504 of the reticle structure 350 .

[0131] In operation S908, when the equilibrium pressure difference is less than the critical pressure, the number of holes of the corresponding frame is determined as the critical number of holes. Figure 6As shown, the critical number of holes is 150. In some embodiments, rather than defining the number of holes or the critical number of holes, the percentage of openings and the critical percentage of openings in the frame 504 of the reticle structure 350 are determined. In some embodiments, the number of holes per unit area and the critical number of holes per unit area are used.

[0132] Fig. 9B The process 950 provides Figure 5A , Figure 5B or Figure 5C The protective film structure shown in FIG. 1 includes an operation S912, wherein a film having a middle portion and a boundary portion surrounding the middle portion is mounted on a frame. Figure 5A , Figure 5B or Figure 5C As shown, the film 65 is mounted on the frame 504. In operation S914, the frame having a plurality of holes is connected to the boundary portion of the film through the first adhesive layer. Figure 5A and Figure 5B As shown, a frame having a plurality of holes 510, 520, and 530 is connected to the border portion 402 of the film 65 through a first adhesive layer 506. In operation S916, a second adhesive layer is connected to a second side of the frame opposite to the first side of the frame. The frame is attached to the reticle via the second adhesive layer to create a closed space between the film, the reticle, and the frame. Figure 5B As shown, frame 504 can be attached to reticle 80 and can form closed space 555. In operation S918, a critical percentage of openings is provided in the frame through a plurality of holes. In some embodiments, the critical percentage of openings maintains an equilibrium pressure difference between the volume inside the closed space and the volume outside the closed space below the critical pressure.

[0133] In some embodiments, the material of the frame is silicon (Si), silicon carbide (SiC), silicon nitride (SiN) or glass. In some embodiments, the material of the frame is aluminum alloy, titanium alloy, invar or Kovar. In some embodiments, the hole is located at the top, bottom or center of the frame 504. The hole has various shapes, including circular or rectangular. In some embodiments, the hole includes a filter to prevent external particles from penetrating into the internal enclosed space and becoming a defect falling on the mask. In some embodiments, the adhesive 506 is a double-sided adhesive and is a silicon (Si), acrylic or epoxy type gel.

[0134] According to some embodiments of the present disclosure, a lithography system includes a reticle structure, which includes a reticle having patterned features, a film, and a frame disposed between the film and the reticle and mounting the film on the patterned features of the reticle. The frame surrounds the patterned features and forms a closed space between the reticle and the film. The frame includes a plurality of holes, and the number of the plurality of holes is greater than a critical number of holes to maintain a balanced pressure difference between the closed space and the outside of the closed space below a critical pressure. The lithography system also includes an exposure device, which includes a radiation source for emitting a radiation beam to reflect and / or project the patterned features of the reticle onto a substrate. The exposure device also includes one or more reflectors to guide the reflected and / or projected patterned features onto the substrate.

[0135] In one embodiment, a plurality of holes produce openings for gas to circulate between the enclosed space and the outside of the enclosed space. When the reticle structure is transferred between the atmospheric pressure outside the exposure device and the vacuum environment inside the exposure device, the opening equalizes the pressure between the enclosed space and the outside of the enclosed space. In one embodiment, a plurality of holes have a circular shape with a diameter of 1 mm. The critical number of a plurality of holes keeps the pressure difference between the enclosed space and the outside of the enclosed space (the critical pressure is 3.5 Pascals) equal. In one embodiment, the lithography system includes an air filter configured in one or more holes in the plurality of holes to prevent a plurality of particles outside the enclosed space from entering the enclosed space. In one embodiment, a plurality of holes have a circular shape with a diameter between 1 mm and 2 mm, the number of the plurality of holes is between 150 holes and 200 holes, and the critical pressure is 2.5 Pascals. In one embodiment, the film includes a middle portion and a first boundary portion surrounding the middle portion. The boundary layer is disposed above the first boundary portion. The film is transparent to the radiation beam emitted by the radiation source, and the material of the boundary layer includes silicon (Si), and the material of the film includes polysilicon, silicide or graphite, while the material of the frame includes silicon (Si), silicon carbide (SiC), silicon nitride (SiN) or glass. In some embodiments, the material of the boundary layer is not transparent to deep ultraviolet or extreme ultraviolet radiation. Another layer containing one or more elements of ruthenium (Ru), molybdenum (Mo), zirconium (Zr), boron (B), niobium (Nb), iridium (Ir), titanium (Ti), its oxide or its oxynitride is arranged on the film on the opposite side of the boundary layer for heat dissipation. In one embodiment, the reticle includes a second boundary portion, which surrounds the patterned features. The frame is connected between the boundary layer on the first boundary portion of the film and the second boundary portion of the reticle. In one embodiment, the first side of the frame is attached to the boundary layer on the first boundary portion of the film through an adhesive layer, and the second side of the frame is attached to the second boundary portion of the reticle through another adhesive layer, and the frame is closed around the patterned features.

[0136] According to some embodiments of the present disclosure, a reticle structure includes: a reticle having a patterned feature and a first boundary portion surrounding the patterned feature; and a film having a middle portion and a second boundary portion surrounding the middle portion. The reticle structure also includes a frame disposed between the film and the reticle for mounting the film on the patterned feature of the reticle. The frame forms an enclosed space between the reticle and the film and surrounds the patterned feature of the reticle. The frame includes a plurality of holes, and the plurality of holes produce a critical percentage of openings in the frame to maintain a balanced pressure difference between the enclosed space and the outside of the enclosed space below a critical pressure.

[0137] In one embodiment, when the reticle structure is transferred between a vacuum environment and an atmospheric pressure environment, the critical percentage of the opening in the frame maintains the equilibrium pressure difference between the enclosed space and the outside of the enclosed space below the critical pressure. In one embodiment, the frame is closed around the patterned features, and the plurality of holes of the frame provide a channel for gas transfer between the enclosed space and the outside of the enclosed space to balance the pressure between the enclosed space and the outside of the enclosed space. In one embodiment, the reticle structure includes an air filter configured in one or more holes in the plurality of holes to prevent a plurality of particles outside the enclosed space from entering the enclosed space. In one embodiment, the top side of the frame is attached to a boundary layer disposed on a second boundary portion of the film through an adhesive layer, and the bottom side of the frame is attached to a first boundary portion of the reticle through another adhesive layer. The film is permeable to deep ultraviolet or extreme ultraviolet radiation. In one embodiment, the thickness of the film is between about 30 nanometers and about 100 nanometers, and the thickness of the frame is between about 2 millimeters and about 4 millimeters. In one embodiment, the critical percentage of the opening is 25%, and the critical pressure is 3.5 Pascals.

[0138] According to some embodiments of the present disclosure, a method for providing a protective film structure includes mounting a film above a frame. The frame has a middle portion and a border portion surrounding the middle portion. The method also includes connecting a frame having a plurality of holes to the border portion of the film from a first side through a first adhesive layer. The frame surrounds the middle portion of the film. The middle portion of the film is transparent to deep ultraviolet or extreme ultraviolet radiation. The method also includes connecting a second adhesive layer to a second side of the frame opposite to the first side of the frame. The frame is attached to a reticle via the second adhesive layer to create an enclosed space between the film, the reticle, and the frame. The method also includes providing a critical percentage of openings in the frame through the plurality of holes to maintain an equilibrium pressure difference below a critical pressure in a volume between the interior of the enclosed space and the exterior of the enclosed space.

[0139] In one embodiment, the method further includes providing a passage for gas between the interior of the enclosed space and the exterior of the enclosed space through a plurality of holes. In one embodiment, the method further includes providing an air filter in one or more of the plurality of holes to prevent a plurality of particles from moving through the holes. In one embodiment, the first adhesive layer and the second adhesive layer are double-sided adhesive layers, the plurality of holes have a circular shape with a diameter between about 0.5 mm and 1 mm, the plurality of holes are evenly distributed on the frame, and the critical percentage of the opening is 25%, and the critical pressure is 2.5 Pascals. In one embodiment, the method further includes providing a boundary layer on a boundary portion of the film and a boundary portion of the film between the first adhesive layer, and the material of the boundary layer comprises silicon (Si) and the material of the film comprises polysilicon, silicide or graphite.

[0140] In some embodiments, implementing the above process and method increases the durability of the reticle structure and improves the quality and stability of the protective film of the reticle structure.

[0141] The foregoing summarizes the features of several embodiments or examples so that those skilled in the art can better understand the various aspects of the present disclosure. Those skilled in the art should understand that they can easily use the present disclosure as a basis for designing or modifying other processes and structures to achieve the same purposes and / or achieve the same benefits as the embodiments or examples introduced herein. Those skilled in the art should also understand that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they can make various changes, substitutions, and modifications herein without departing from the spirit and scope of the present disclosure.

Claims

1. A lithography system, characterized in that: Include: A reticle structure, comprising: a reticle having a plurality of patterned features; a film comprising a middle portion and a first boundary portion surrounding the middle portion; and a frame disposed between the film and the reticle and used to mount the film on the plurality of patterned features of the reticle, wherein the frame surrounds the plurality of patterned features and creates a closed space between the reticle and the film, wherein the frame includes a plurality of holes, and wherein a number of the plurality of holes is greater than a critical number of the plurality of holes to maintain a balanced pressure difference between the enclosed space and the outside of the enclosed space at a critical pressure, and wherein the plurality of holes includes at least one slit hole having three sides formed by the frame and one side formed by the first boundary portion of the film; as well as an exposure apparatus comprising a radiation source for emitting a radiation beam to reflect and / or project the plurality of patterned features of the reticle onto a substrate; as well as The exposure apparatus further comprises one or more mirrors for directing the reflected and / or projected patterned features onto the substrate.

2. The lithography system according to claim 1, characterized in that: The plurality of holes are used to create an opening to allow gas to flow between the enclosed space and outside the enclosed space, and wherein the opening is used to balance the pressure between the enclosed space and outside the enclosed space when the reticle structure is transferred between the atmospheric pressure outside the exposure device and a vacuum environment inside the exposure device.

3. The lithography system according to claim 2, characterized in that: The plurality of holes have a circular shape with a diameter of 1 mm, wherein the critical number of the plurality of holes is used to maintain a balanced pressure difference between the enclosed space and the outside of the enclosed space, and wherein the critical pressure is 3.5 Pascals.

4. The lithography system according to claim 3, characterized in that: Further including: An air filter is disposed in one or more of the plurality of holes to prevent a plurality of particles outside the closed space from entering the closed space.

5. The lithography system according to claim 3, characterized in that: The plurality of holes have a circular shape with a diameter between 1 mm and 2 mm, wherein a number of the plurality of holes is between 150 holes and 200 holes, and wherein the critical pressure is 2.5 Pascals.

6. The lithography system according to claim 1, characterized in that: A boundary layer is disposed above the first boundary portion, wherein the radiation beam emitted by the radiation source can penetrate the thin film, wherein a material of the boundary layer includes silicon and a material of the thin film includes polysilicon, silicide or graphite, wherein a material of the frame includes silicon, silicon carbide, silicon nitride or glass, and wherein another layer includes one or more elements ruthenium, molybdenum, zirconium, boron, niobium, iridium, titanium, their oxides or their oxynitrides disposed on the thin film on the opposite side of the boundary layer for heat dissipation.

7. The lithography system according to claim 6, characterized in that: The reticle includes a second boundary portion surrounding the plurality of patterned features, and wherein the frame is coupled between the boundary layer on the first boundary portion of the pellicle and the second boundary portion of the reticle.

8. The lithography system according to claim 7, characterized in that: A first side of the frame is attached to the boundary layer on the first boundary portion of the film through an adhesive layer, and a second side of the frame is attached to the second boundary portion of the reticle through another adhesive layer, and wherein the frame is enclosed around the plurality of patterned features.

9. A reticle structure, characterized in that: Include: a reticle having a plurality of patterned features and a first boundary portion surrounding the plurality of patterned features; A film having a middle portion and a second boundary portion surrounding the middle portion; as well as A frame is disposed between the film and the reticle and used to mount the film on the plurality of patterned features of the reticle, wherein the frame forms a closed space between the reticle and the film and surrounds the plurality of patterned features of the reticle, wherein the frame includes a plurality of holes, and wherein the plurality of holes produce a critical percentage of openings in the frame to maintain an equilibrium pressure difference between the closed space and the outside of the closed space below a critical pressure, and wherein the plurality of holes include at least one slit hole having one side formed by the second boundary portion of the film and three sides formed by the frame.

10. The reticle structure according to claim 9, characterized in that: The critical percentage of the opening in the frame is used to maintain the equilibrium pressure difference between the enclosed space and the exterior of the enclosed space below the critical pressure when the reticle structure is transferred between a vacuum environment and an atmospheric pressure environment.

11. The reticle structure according to claim 10, characterized in that: The frame encloses and surrounds the plurality of patterned features, and wherein the plurality of holes of the frame provide a passage for gas transfer between the enclosed space and the outside of the enclosed space to balance a pressure between the enclosed space and the outside of the enclosed space.

12. The reticle structure according to claim 10, characterized in that: Further including: An air filter is disposed in one or more of the plurality of holes to prevent a plurality of particles outside the closed space from entering the closed space.

13. The reticle structure according to claim 9, characterized in that: A top side of the frame is attached to a boundary layer disposed on the second boundary portion of the film through an adhesive layer, and a bottom side of the frame is attached to the first boundary portion of the reticle through another adhesive layer, wherein deep ultraviolet or extreme ultraviolet radiation can penetrate the film.

14. The reticle structure according to claim 9, characterized in that: A thickness of the film is between 30 nanometers and 100 nanometers, and a thickness of the frame is between 2 millimeters and 4 millimeters.

15. The reticle structure according to claim 9, characterized in that: The critical percentage of opening is 25%, and the critical pressure is 3.5 Pascals.

16. A method for manufacturing a reticle structure, characterized in that: Include: Mounting a film on a frame, wherein the film comprises a middle portion and a boundary portion surrounding the middle portion; Connecting the frame having a plurality of holes to the border portion of the film from a first side through a first adhesive layer, wherein the frame surrounds the middle portion of the film, and wherein deep ultraviolet or extreme ultraviolet radiation can penetrate the middle portion of the film; connecting a second adhesive layer to a second side of the frame opposite the first side of the frame, wherein the frame is adapted to be attached to a reticle via the second adhesive layer to create a closed space between the film, the reticle, and the frame; as well as A critical percentage of opening is provided in the frame through the plurality of holes, wherein the critical percentage of opening maintains an equilibrium pressure differential below a critical pressure in a volume between the interior of the enclosed space and the exterior of the enclosed space, and wherein the plurality of holes includes at least one slit hole having one side formed by the boundary portion of the film and three sides formed by the frame.

17. The method for manufacturing a reticle structure according to claim 16, characterized in that: Further including: An air filter is installed in one or more of the plurality of holes to prevent a plurality of particles from passing through the plurality of holes.

18. The method for manufacturing a reticle structure according to claim 16, characterized in that: Further including: A boundary layer is disposed on the boundary portion of the film between the boundary portion of the film and the first adhesive layer, wherein a material of the boundary layer includes silicon, and wherein a material of the film includes polysilicon, silicide, or graphite.

19. The method for manufacturing a reticle structure according to claim 16, characterized in that: Further including: A passage for gas transfer between the interior of the enclosed space and the exterior of the enclosed space is provided through the plurality of holes.

20. The method for manufacturing a reticle structure according to claim 16, wherein: The first adhesive layer and the second adhesive layer are a plurality of double-sided adhesive layers; The plurality of holes have a circular shape with a diameter between 0.5 mm and 1 mm; The plurality of holes are evenly distributed on the frame; as well as The critical percentage of the opening is 25% and the critical pressure is 2.5 Pascals.

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