Method of manufacturing a membrane assembly

Abstract

A method of manufacturing a membrane assembly for EUV lithography is provided in which a layer forming at least a portion of a pellicle membrane is provided after one or more etching steps defining a pellicle boundary retaining the pellicle membrane. Also provided is a pellicle substrate comprising a stack having a front side and a back side, where one or more layers on the back side of the stack have been selectively removed to define a pellicle boundary region for holding the pellicle membrane before a layer forming at least a portion of the pellicle membrane has been disposed.

Description

[0001] This application is a divisional application with application number 201980084798.3, entry date June 18, 2021, and invention name “Method for manufacturing a diaphragm assembly”. Technical Field

[0002] The present invention relates to a method of manufacturing a diaphragm assembly and to a diaphragm assembly precursor. The present invention has particular, but not exclusive, use in conjunction with EUV lithography apparatus and EUV lithography tools. Background Art

[0003] A lithographic apparatus is a machine configured to apply a desired pattern to a substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithographic apparatus can, for example, project a pattern from a patterning device (e.g., a mask) onto a layer of radiation-sensitive material (resist) provided on the substrate.

[0004] To project a pattern onto a substrate, a lithographic apparatus uses electromagnetic radiation. The wavelength of this radiation determines the minimum size of features that can be formed on the substrate. Compared to conventional lithographic apparatus (which may, for example, use electromagnetic radiation with a wavelength of 193 nm), lithographic apparatus using extreme ultraviolet (EUV) radiation with a wavelength in the 4-20 nm range (e.g., 6.7 nm or 13.5 nm) can be used to form smaller features on substrates.

[0005] A patterning device (e.g., a mask or reticle) can be used to impart a pattern to a radiation beam in a lithographic apparatus. Radiation is provided to pass through or reflect from the patterning device to form an image on a substrate. Contamination on the surface of the patterning device can cause manufacturing defects on the substrate. A diaphragm assembly (also known as a pellicle) can be provided to protect the patterning device from airborne particles and other forms of contamination.

[0006] A pellicle may also be provided to protect optical components other than the patterning device. The pellicle may also be used to provide a path for lithographic radiation between sealed regions of the lithographic apparatus. The pellicle may also function as a radiation filter (such as a spectral purity filter) or as part of a dynamic airlock in the lithographic apparatus.

[0007] The use of pellicles in photolithography is well known and recognized. A pellicle in a lithographic apparatus is a membrane (also called a pellicle membrane) positioned away from the patterning device and outside the focal plane of the lithographic apparatus in use. Because the pellicle is outside the focal plane of the lithographic apparatus, contaminant particles that land on the pellicle are out of focus. Consequently, the image of the contaminant particles is not projected onto the substrate. Without a pellicle, contaminant particles that land on the patterning device would be projected onto the substrate and introduce defects into the projected pattern.

[0008] A mask assembly can include a pellicle that protects a patterning device (e.g., a mask) from particle contamination. The pellicle membrane can be supported by a pellicle border, thereby forming a pellicle assembly or membrane assembly. The pellicle can be attached to the pellicle frame, for example, by gluing or otherwise attaching the pellicle border to the pellicle frame. The pellicle frame can be permanently or removably attached to the patterning device. The pellicle membrane can also be referred to as a pellicle layer. The pellicle membrane is manufactured starting from a stack comprising at least one substrate and a layer deposited on the substrate.

[0009] For example, because the diaphragm is relatively thin, it is difficult to manufacture a diaphragm membrane or diaphragm assembly without deforming or damaging the diaphragm assembly during the process. Damage or defects in the diaphragm assembly can lead to undesirable performance degradation, shortened service life, or even breakage. It would be desirable to provide a method for manufacturing a diaphragm membrane that provides improved yield and / or strength for the diaphragm and minimizes damage or defects in the diaphragm assembly.

[0010] The production of the pellicle assembly is also time consuming.Therefore, it would be desirable to provide a method of manufacturing the pellicle that has a reduced cycle time and / or allows for faster production of the pellicle assembly compared to existing methods.

[0011] Although this application generally refers to pellicles in the context of lithographic apparatus, specifically EUV lithographic apparatus, the present invention is not limited to pellicles and lithographic apparatus, and it should be understood that the subject matter of the present invention may be used in any other suitable apparatus or context. Furthermore, the present invention is not specifically limited to EUV lithography and may also be used in lithography using radiation of longer or preferably shorter wavelengths than EUV.

[0012] Due to the presence of the pellicle in the optical path of the EUV radiation beam, it is desirable for the pellicle to have a high EUV transmittance. High EUV transmittance allows a larger proportion of the incident radiation to pass through the pellicle. In addition, reducing the amount of EUV radiation absorbed by the pellicle can reduce the operating temperature of the pellicle. Since the transmittance depends at least in part on the thickness of the pellicle, it is necessary to provide a pellicle that is as thin as possible while maintaining sufficient strength to withstand the sometimes harsh environment within the lithographic equipment. Desired Properties of the Pellicle Being as thin as possible means that the pellicle membrane itself is susceptible to damage during manufacturing. Small defects or damaged areas in an extremely thin pellicle can be detrimental to the physical properties of the pellicle.

[0013] Because any defects in the diaphragm may reduce the performance of the diaphragm and / or shorten the life of the diaphragm, it is desirable to reduce the likelihood that a diaphragm component, such as a diaphragm, will be deformed or damaged during its manufacture. Because the process of manufacturing diaphragms is time-consuming and costly, it is also desirable to increase the yield of undamaged diaphragms during manufacturing.

[0014] Etching is a common manufacturing process used to remove portions of material. In multilayer materials, selective etching can remove portions of the outer surface layer, exposing underlying layers. Since etching typically occurs at a fixed rate (thus, thicker layers take longer to etch than thinner layers), a well-defined layer thickness is beneficial. Similarly, it is understood that uneven layer thicknesses can lead to differences in etching times depending on the thickness of each portion of the layer. Overetching can occur when more material than intended is removed. Overetching can occur in films with uneven layer thicknesses, as thinner portions of a layer may be etched before thicker portions have finished etching. This can damage underlying or overlying layers (depending on which side of the stack is being etched). Overetching in pellicle manufacturing can damage the pellicle. Therefore, there is a need to reduce the incidence of overetching. There is also a need to establish manufacturing processes that facilitate the deposition of layers with well-defined layer thicknesses and / or the controlled removal of material to achieve reliable and consistent properties for pellicle membranes and pellicle assemblies.

[0015] The present invention has been designed in an attempt to address at least some of the problems set forth above. Summary of the Invention

[0016] According to a first aspect of the present invention, a method of manufacturing a pellicle membrane and / or a pellicle assembly for EUV lithography is provided, wherein after one or more etching steps defining a pellicle boundary retaining the pellicle membrane, a layer forming at least a portion of the pellicle membrane is provided.

[0017] Fabricating a pellicle involves multiple steps of material deposition and removal using methods such as, but not limited to, chemical vapor deposition, etch masking, and etching. During these processes, the stack is handled and manipulated to align it with the desired orientation. In some stages, the stack may be flipped, and in other stages, a securing mechanism, such as a chuck, may be used to hold the stack in place. These chucks can apply forces to layers in the stack during fabrication, potentially causing damage. The chucks may also scratch or otherwise damage one or more layers in the stack.

[0018] In other methods for manufacturing pellicle membranes and membrane assemblies for EUV lithography, one or more layers that will ultimately form the pellicle membrane are deposited early in the process. This allows the pellicle membrane layers to be deposited or otherwise applied onto a clean surface that is essentially free of contamination or defects. After deposition of the one or more layers that will ultimately form the pellicle membrane, further deposition, protection, and etching steps are performed to form the final pellicle membrane or pellicle assembly. However, during these other processing steps, one or more layers that will ultimately form the pellicle membrane may become damaged. With other manufacturing methods, the final pellicle membrane layer is covered by other layers until later in the process. Therefore, if any defects or damage exist in the final pellicle membrane, these defects or damage are not covered until several complex and time-consuming steps have already been performed. Consequently, nearly the entire manufacturing process must be completed before a defective pellicle membrane can be identified and addressed. The time between identifying a fault and forming a new pellicle assembly can be referred to as a learning period. The method according to the present invention offers the advantage of a reduced learning period.

[0019] In the method according to the first aspect of the present invention, the one or more layers that ultimately form the pellicle membrane are applied at a later stage in the process than in other methods. In the present invention, the final pellicle membrane layer is deposited only after certain etching steps have occurred. The final pellicle assembly includes a pellicle boundary that retains the pellicle membrane. The pellicle boundary can be mechanically or chemically attached to a pellicle frame. The pellicle frame can be removably or permanently attached to the patterning device MA. By pellicle barrier, it should be understood that this refers to one or more layers of material that span the pellicle boundary portion and are passed through by EUV radiation when used as a pellicle. This layer may also be referred to as a pellicle layer, a pellicle core layer, or a pellicle membrane. The material that forms the pellicle membrane is applied after the one or more etching steps that define the pellicle boundary have occurred. It should be understood that this does not require the pellicle boundary to have already been formed, but rather requires that one or more layers that protect the portion of the layer (such as the planar substrate) that ultimately becomes the pellicle boundary according to subsequent etching steps have already been defined. For example, where the stack includes a silicon planar substrate that forms a final pellicle boundary that retains the pellicle diaphragm, the etching step that defines the final pellicle boundary may include etching one or more layers that protect the portion of the planar substrate that is etched to ultimately form the pellicle boundary.

[0020] Surprisingly, it has been discovered that it is possible to apply the layer or membrane that will ultimately form at least a portion of the final pellicle membrane after some etching steps have already been performed, without compromising the quality of the final pellicle membrane. Furthermore, the method of the present invention can also shorten the time required to produce a pellicle assembly, since some of the steps required to manufacture the pellicle assembly or pellicle membrane from the stack can be performed before applying the layer or membrane that will become the final pellicle membrane. In other manufacturing methods that require depositing the pellicle membrane layer at an early stage, if a diaphragm assembly having a specific pellicle membrane is desired, it is necessary to begin forming the pellicle membrane from the very beginning of the process. In contrast, with the method of the present invention, formation of the pellicle membrane layer can be effectively initiated midway through the overall process, thereby saving time.

[0021] The method may include providing a stack having a front side and a back side. The stack may include a substrate having one or more layers. For example, the stack may include a planar substrate such as a silicon wafer or a silicon-on-insulator (SOI) wafer.

[0022] The method may further comprise providing a protective layer on the front side of the stack. The protective layer may be any suitable material capable of protecting the lower portion of the stack from subsequent etching processes. The present invention is not particularly limited by the nature of the protective layer.

[0023] The method may also include selectively removing one or more portions from the back side of the stack. These portions may be used to define the pellicle boundaries of the final pellicle assembly. This selective removal may be performed by any suitable technique, and the present invention is not particularly limited by the technique used. During manufacturing processes (such as resist deposition, patterning and etching), a fixing mechanism (also known as a chuck) must be used to hold or move the stack in place. In alternative manufacturing methods, these chucks may apply forces to the pellicle layer during manufacturing, which may further cause damage to the pellicle. An advantage of the present invention is that the selective removal of at least a portion of the back side of the stack is completed before depositing at least one diaphragm layer, thereby ensuring that the chuck does not apply force to the diaphragm layer at this time. This reduces the possibility of damage to the pellicle diaphragm or layer during processing.

[0024] The method may further comprise removing at least a portion of the protective layer from the front side of the stack. Once the back side of the stack has been etched, the protective layer on the front side of the stack may be removed because it is no longer needed to protect from the etching. Removal of the protective layer may be accomplished by any suitable technique, and the present invention is not particularly limited by the technique used.

[0025] The method may further comprise providing a layer forming at least a portion of the pellicle membrane on the front side of the stack. While it will be appreciated that a protective layer is preferably provided on the front side of the stack to protect the front side of the stack during the etching step, this is not essential, and the back side of the stack may be etched without providing any protective layer on the front side of the stack. Because the back side of the stack is etched prior to providing the layer forming at least a portion of the pellicle membrane, the risk of damaging such pellicle layer is reduced. The present invention is not particularly limited to how the pellicle layer is provided, and any suitable technique, such as chemical vapor deposition, may be used.

[0026] The method may also include selectively removing one or more portions of the stack to form a pellicle assembly. Thus, the pellicle assembly may include a pellicle membrane comprising at least one membrane layer and a pellicle boundary retaining the pellicle membrane. The one or more portions may be removed from the stack by any suitable technique, and the present invention is not limited by the particular technique or techniques used. For example, etching may be used to remove the one or more portions. The method may include one or more steps for selectively removing one or more portions of the stack to form the pellicle assembly.

[0027] The method may further include: providing at least one emissive layer on the front surface of the stack, such that the pellicle assembly comprises a diaphragm, the diaphragm comprising at least one diaphragm layer and at least one emissive layer. The emissive layer is preferably provided after the at least one diaphragm layer has been provided. The emissive layer may be provided below the at least one diaphragm layer, or both above and below the at least one diaphragm layer. Thus, the emissive layer may be provided on the front, back, or both sides of the pellicle diaphragm. The emissive layer may serve to increase the thermal emissivity of the pellicle assembly. This increased emissivity may reduce the operating temperature of the pellicle, which in turn may increase the lifespan of the pellicle. Furthermore, the emissive layer may protect the pellicle layer from the atmosphere within the lithographic apparatus. For example, if the pellicle layer comprises carbon, low-pressure hydrogen gas within the lithographic apparatus may be ionized by radiation, and hydrogen radicals may erode the carbon over time, weakening the pellicle. Therefore, the emissive layer may also protect the pellicle diaphragm layer. If the emissive layer is provided on the back surface of the at least one diaphragm layer, it may also be provided on the inner side of the boundary. Alternatively or additionally, the emissive layer may also be provided on the lowest part of the boundary, ie the boundary's "foot". Although it is possible to provide the emissive layer only on the diaphragm layer, it may be more convenient to coat only the lowest face of the component with the emissive layer.

[0028] The method may further comprise providing at least one capping layer on the front face of the stack, wherein the capping layer preferably comprises silicon dioxide and / or silicon nitride. Other capping layers may also be used. The capping layer may be provided by any suitable technique, and the invention is not particularly limited by the technique used. In an example, tetraethyl orthosilicate (TEOS) may be provided and subsequently converted to silicon dioxide using known techniques. The capping layer may serve to protect the surface film core layer of the stack. The capping layer may have better compatibility with the upper layer and thereby result in stronger bonding between the layers in the stack. Thinner layers of silicon dioxide are easier to grow to have a well-known layer thickness known in the art. Layers of well-known thickness are advantageous for the etching process because they reduce the risk of over-etching some areas of the layer due to uneven layer thickness. Depositing a thinner layer of silicon dioxide as a capping layer may subsequently increase the reliability of the etching and may reduce the chance of damage to the diaphragm.

[0029] The method may comprise providing a resist on the stack and patterning the resist prior to the step of selectively removing one or more portions from the back side of the stack. The invention is not particularly limited by the nature of the resist and any suitable resist may be used. This step will provide a mask that allows a pattern to be defined on the surface of the stack, for example allowing a pellicle boundary region to be defined on the stack. The resist may be patterned in such a way as to define the final pellicle boundary of the final pellicle assembly. The resist serves to protect underlying layers from etching. Thus, the patterning of the resist serves to define the areas of the stack that are removed by a subsequent etching step. The etchant may be a chemical etchant such as phosphoric acid (H3PO4) and / or hydrofluoric acid (HF). After etching, the resulting pellicle membrane may comprise, for example, MoSiN with a native oxide layer on one or both surfaces. x In this article, x means the change of nitrogen in the material composition, which can also be equivalently described as Mo t Si p N z Alternatively, after etching and metal deposition, for example from SiN / O on the front surface x A stack is formed of a pSi pellicle core layer / low stress nitride (LSN) and a Mo / Ru cap on the back side of the stack (eg, in a cavity defined by the pellicle boundary).

[0030] The method may further include etching at least a portion of the stack during the step of selectively removing one or more portions from the back side of the stack and / or during the step of selectively removing one or more portions of the stack to form the pellicle assembly.

[0031] The stack may include a planar substrate and preferably at least one sacrificial layer. The planar substrate may be a wafer. The planar substrate may form the core layer of the stack. Preferably, the wafer comprises silicon. Silicon is a well-characterized material commonly used in the art. It will be appreciated that other suitable materials may be used, and that the present invention is not limited to silicon-based substrates (i.e., substrates comprising silicon, such as pSi, SiC, MoSi2, or MoSiN). x For example, the substrate may also be carbon-based, such as a graphene core layer or a carbon nanotube core layer for a laminate.

[0032] The method may also include depositing one or more additional sacrificial layers, for example, during the deposition of the at least one diaphragm layer. This is preferably followed by the selective removal of one or more portions of the additional sacrificial layers. The sacrificial layers may comprise silicon nitride and / or silicon oxide. Other materials may also be used as sacrificial layers, depending on the material of the diaphragm core layer.

[0033] The at least one diaphragm layer may include at least one silicon layer, preferably formed by crystallizing at least one amorphous silicon layer. The diaphragm layer may comprise pSi. Silicon is a suitable material for the at least one diaphragm layer due to its good EUV transmittance. The at least one diaphragm layer may be coated with one or more materials that provide additional chemical or thermal resistance and / or increase the emissivity of the diaphragm assembly.

[0034] The protective layer may include a cross-linked polymer. The polymer may be a polyparaxylene polymer. The polymer may be Parylene or a ProTek® type material. Alternatively or in addition, the polymer includes a resist such as KMPR™.

[0035] At least one diaphragm layer may be disposed between at least one emissive layer and the front face of the stack. It should be understood that in some embodiments, the emissive layer may be disposed on one or both sides of the diaphragm layer. In embodiments, the diaphragm layer does not have an emissive layer or other capping layer, and the diaphragm layer is formed solely from at least one pellicle core layer. For example, the pellicle may be formed solely from MoSiN x The core layer of the surface membrane is formed.

[0036] At least one emissive layer can be metallic. It can include boron or a boron-containing material, or zirconium or a zirconium-containing material. Boron-containing materials (e.g., boron-containing metal alloys such as zirconium diboride (ZrB2)) can increase the emissivity of the pellicle and also protect the diaphragm layer.

[0037] Preferably, at least one emissive layer may further comprise three metal emissive layers. In this embodiment, the three emissive layers may comprise a zirconium layer disposed between two boron layers, wherein the zirconium layer may comprise zirconium or a zirconium-containing material, and wherein the boron layer may comprise boron or a boron-containing material. In other alternatives, the emissive layer may comprise a layer of B, Zr, Ru, or Mo. Other emissive layers may be used.

[0038] At least one cap layer has a cap layer thickness, and at least one diaphragm layer has a diaphragm layer thickness, with the cap layer thickness preferably being less than the diaphragm layer thickness. For example, the cap layer may have a thickness of 0.5 nm to 10 nm (preferably 1 nm to 5 nm). Thus, the diaphragm layer provides the majority of the physical strength of the diaphragm in the diaphragm assembly.

[0039] The method may further include selectively removing at least a portion of the at least one cover layer after selectively removing one or more portions of the stack to form the pellicle assembly.

[0040] At least one diaphragm layer and / or at least one cap layer and / or at least one emitter layer may further be provided with at least one sacrificial layer. The method may further comprise providing an additional sacrificial layer, for example before, during, or after depositing the at least one diaphragm layer. This is preferably followed by selective removal of one or more portions of the additional sacrificial layer.

[0041] According to a second aspect of the invention, there is provided a pellicle substrate comprising: a laminate having a front side and a back side, wherein, before a layer forming at least a portion of the pellicle membrane has been provided, one or more layers on the back side of the laminate have been selectively removed to define a pellicle boundary region for retaining the pellicle membrane.

[0042] The present invention allows for the provision of a partially processed pellicle substrate. Since processing a pellicle substrate can take several weeks, the ability to provide a partially processed pellicle substrate makes it possible to store such substrates until they are needed, thereby reducing the time required to order a diaphragm assembly with a specific pellicle membrane. During manufacturing, defects in the pellicle layer may be identified, in which case the pellicle must be discarded and a new pellicle assembly manufactured. According to these aspects of the invention, the manufacturing process can continue from the moment the pellicle substrate is provided, rather than from a starting point, thereby reducing the learning curve for the manufacturing process.

[0043] In some embodiments, the pellicle substrate may not include a layer that will form at least a portion of the pellicle membrane. In this embodiment, the pellicle substrate has been processed such that the final pellicle boundary region is defined, but the material that will form the pellicle membrane is absent. This allows different pellicle membrane materials to be provided and studied, or used more quickly than previously possible.

[0044] In another embodiment, the pellicle substrate comprises the material that will form the final pellicle membrane. However, this material is provided after the processing steps that define the final pellicle boundary region have been performed.

[0045] Preferably, the pellicle substrate comprises at least one protective layer on said front side, preferably said at least one protective layer comprises a cross-linked polymer, preferably a polyparaxylene polymer, preferably a Parylene or ProTEK® type material, or an anti-etching agent such as KMPR™.

[0046] The stack may comprise a planar substrate and preferably comprises at least one sacrificial layer; preferably wherein the planar substrate is a wafer, optionally a silicon wafer or an SOI wafer; and preferably wherein the at least one sacrificial layer comprises silicon nitride.

[0047] According to another aspect of the present invention, there is provided a pellicle assembly manufactured according to a method including any one of the methods described above.

[0048] In an embodiment, the method according to the invention has the following result: after etching, the diaphragm membrane comprises MoSiN without further functional capping layers. x A core layer, or MoSiN having at least one surface covered with a native oxide layer x core layer.

[0049] In an embodiment, the method according to the invention has the following result: after etching and metal deposition, the SiN / O x , a pSi pellicle core layer, a low stress nitride (LSN) layer, and a cap layer of Ru on Mo deposited on the back side of the stack form a pellicle stack.

[0050] In another aspect of the present invention, the pellicle substrate comprises a pellicle core layer which may be selected from: a silicon-based material such as pSi, SiC, MoSi2 or MoSiN x ; or a carbon-based material, such as a graphene film or a film formed of carbon nanotubes.

[0051] In another aspect of the present invention, the film stack comprises SiO / MoSiN x / MoSi2 layer or a layer including SiON / MoSiN x However, combinations of only two of these layers are also envisaged herein.

[0052] While it should be appreciated that while the final pellicle provided by the present invention is fundamentally the same as pellicle assemblies manufactured using other methods, providing the pellicle layer at a later stage in the process has several previously unrealized benefits as detailed above.

[0053] It should be understood that any one of the above-mentioned aspects of the present invention may be combined with one or more other aspects of the present invention in appropriate circumstances. In addition, the optionally selected features described relative to one of the aspects of the present invention may be optionally selected as features of one of the other aspects of the present invention in appropriate circumstances. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which:

[0055] Figure 1 Depicting a lithographic system comprising a lithographic apparatus including a pellicle assembly;

[0056] Figure 2 Describe the membrane components;

[0057] Figure 3A and Figure 3B illustrating the stages of manufacturing a pellicle assembly according to a method other than the method according to the invention, which is illustrated using a cross section of a stack;

[0058] Figure 4A and Figure 4B illustrates stages in manufacturing a pellicle assembly according to an embodiment of the present invention, illustrated using a cross-section of a stack;

[0059] Figure 5 depicts an embodiment of the present invention after depositing multiple membrane layers;

[0060] FIG6 depicts an embodiment of the final pellicle assembly of the present invention before and after final etching;

[0061] Figure 7 depicts another embodiment of the present invention after depositing a plurality of diaphragm layers;

[0062] FIG8 depicts another embodiment of the final pellicle assembly of the present invention before and after final etching; and

[0063] Figure 9 An embodiment of a pellicle assembly is depicted in which an emissive layer is disposed on the back side of the assembly.

[0064] The features and advantages of the present invention will become more apparent from the detailed description set forth below in conjunction with the accompanying drawings, in which like reference numerals identify corresponding elements throughout. In the accompanying drawings, like reference numerals generally indicate identical, functionally similar, and / or structurally similar elements. DETAILED DESCRIPTION

[0065] Figure 1A lithographic system is shown that includes a pellicle 15 (also referred to as a pellicle assembly) manufactured according to the method of the first aspect of the present invention. The lithographic system comprises a radiation source SO and a lithographic apparatus LA. The radiation source SO is configured to generate an extreme ultraviolet (EUV) radiation beam B and supply the EUV radiation beam B to the lithographic apparatus LA. The lithographic apparatus LA comprises an illumination system IL, a support structure MT configured to support a patterning device MA (e.g., a mask), a projection system PS, and a substrate table WT configured to support a substrate W.

[0066] The illumination system IL is configured to condition the radiation beam B before it is incident on the patterning device MA. The projection system is configured to project the radiation beam B (now patterned by the mask MA) onto a substrate W. The substrate W may include a previously formed pattern. In this case, the lithographic apparatus aligns the patterned radiation beam B with the pattern previously formed on the substrate W. In this embodiment, a pellicle assembly 15 is depicted in the path of the radiation and is protecting the patterning device MA. It should be understood that the pellicle assembly 15 can be located in any desired location and can be used to protect any of the mirrors in the lithographic apparatus.

[0067] The radiation source SO, illumination system IL, and projection system PS may be constructed and arranged so as to be isolated from the external environment. A gas (e.g., hydrogen) at a pressure below atmospheric pressure may be provided in the radiation source SO. A vacuum may be provided in the illumination system IL and / or the projection system PS. A small amount of gas (e.g., hydrogen) at a pressure substantially below atmospheric pressure may be provided in the illumination system IL and / or the projection system PS.

[0068] The radiation source SO may take any form and may, for example, be of a type that may be referred to as a laser produced plasma (LPP) source. In an alternative example, the radiation source SO may include one or more free electron lasers. The one or more free electron lasers may be configured to emit EUV radiation that may be provided to one or more lithographic apparatuses.

[0069] A radiation beam B is transmitted from a radiation source SO into an illumination system IL, which is configured to condition the radiation beam. The illumination system IL may include a faceted field mirror arrangement 10 and a faceted pupil mirror arrangement 11. Together, the faceted field mirror arrangement 10 and the faceted pupil mirror arrangement 11 provide the radiation beam B with a desired cross-sectional shape and a desired angular distribution. The radiation beam B passes from the illumination system IL and is incident on a patterning device MA held by a support structure MT. The patterning device MA is protected by a pellicle layer 19, which is held in place by a pellicle boundary 17. The pellicle layer 19 and the pellicle boundary 17 together form a pellicle assembly 15. The patterning device MA, which may be, for example, a mask, reflects and patterns the radiation beam B. The illumination system IL may include other mirrors or devices in addition to or instead of the faceted field mirror arrangement 10 and the faceted pupil mirror arrangement 11.

[0070] After reflection from the patterning device MA, the patterned radiation beam B enters the projection system PS. The projection system comprises a plurality of mirrors 13, 14 configured to project the radiation beam B onto a substrate W held by a substrate table WT. The projection system PS may apply a reduction factor to the radiation beam so as to form an image in which features are smaller than corresponding features on the patterning device MA. For example, a reduction factor of 4 may be applied. Although Figure 1 The projection system PS in FIG. 1 has two mirrors 13 , 14 , but the projection system may comprise any number of mirrors (eg six mirrors).

[0071] Figure 1 The radiation source SO shown may include components not shown. For example, a spectral filter may be provided in the radiation source. The spectral filter may substantially transmit EUV radiation but substantially block radiation of other wavelengths, such as infrared radiation.

[0072] As briefly described above, pellicle assembly 15 includes pellicle layer 19 disposed adjacent to patterning device MA. Pellicle layer 19 is disposed in the path of radiation beam B such that radiation beam B passes through pellicle layer 19 as it approaches patterning device MA from illumination system IL and as it is reflected by patterning device MA toward projection system PS. Pellicle layer 19 comprises a membrane that is substantially transparent to EUV radiation (although it will absorb a small amount of EUV radiation). Pellicle layer 19 serves to protect patterning device MA from particle contamination. Pellicle layer 19 may be referred to herein as an EUV transparent pellicle.

[0073] Despite efforts to maintain a clean environment within the lithographic apparatus LA, particles may still be present within the lithographic apparatus LA. In the absence of the pellicle layer 19, particles may be deposited on the patterning device MA. Particles on the patterning device MA may adversely affect the pattern imparted to the radiation beam B and, therefore, the pattern transferred to the substrate W. The pellicle layer 19 provides a barrier between the patterning device MA and the environment within the lithographic apparatus LA to prevent particles from being deposited on the patterning device MA.

[0074] In use, pellicle layer 19 is positioned at a distance from patterning device MA sufficient to prevent any particles incident on the surface of pellicle layer 19 from being in the focal plane of radiation beam B. The spacing between pellicle layer 19 and patterning device MA serves to reduce the extent to which any particles on the surface of pellicle layer 19 impart a pattern to radiation beam B. It will be appreciated that if a particle is present in radiation beam B but not at a location in the focal plane of radiation beam B (i.e., not at the surface of patterning device MA), any image of that particle will not be focused at the surface of substrate W. In some embodiments, the spacing between pellicle layer 19 and patterning device MA may be, for example, between 2 mm and 3 mm (e.g., approximately 2.5 mm). In some embodiments, the spacing between pellicle layer 19 and patterning device MA may be adjustable.

[0075] In one embodiment, diaphragm assembly 15 is used for a dynamic gas lock. In this case, diaphragm assembly 15 acts as a filter for filtering DUV radiation. Additionally or alternatively, in one embodiment, diaphragm assembly 15 is a diaphragm for a patterning device MA used for EUV lithography. The diaphragm assembly 15 of the present invention can be used for a dynamic gas lock, a diaphragm, or for another purpose. In one embodiment, diaphragm assembly 15 includes a diaphragm formed from at least one diaphragm layer configured to transmit at least 90% of incident EUV radiation. To ensure maximum EUV transmission and minimize impact on imaging performance, it is preferred that the diaphragm be supported only at its edges.

[0076] Figure 2Schematic illustration of the pellicle assembly 15 and the patterning device MA in cross-section and in greater detail. The patterning device MA has a patterned surface 24. A pellicle border 17 supports the pellicle layer 19 around a peripheral portion thereof. The pellicle border 17 can be attached to a pellicle frame 22. The pellicle frame 22 can include an attachment mechanism (not shown) configured to allow the pellicle frame 22 to be removably attached to the patterning device MA (i.e., to allow the pellicle frame 22 to be attached to and detached from the patterning device MA). The attachment mechanism is configured to engage with an attachment feature (not shown) provided on the patterning device MA. The attachment feature can be, for example, a protrusion extending from the patterning device MA. The attachment mechanism can, for example, include a locking member that engages with the protrusion and secures the pellicle frame 22 to the patterning device MA. Multiple attachment mechanisms and associated attachment features can be provided. The attachment mechanisms may be distributed around the pellicle frame 22 (eg, two attachment mechanisms on one side of the pellicle frame and two attachment mechanisms on the opposite side of the pellicle frame).The associated attachment features may be distributed around the perimeter of the patterning device MA.

[0077] Figure 2 Schematically shown are contamination particles 26. Contamination particles 26 are incident on and retained by pellicle layer 19. Pellicle layer 19 retains the contamination particles sufficiently away from patterned surface 24 of mask MA that they are not imaged onto the substrate by lithographic apparatus LA.

[0078] Pellicle assemblies according to embodiments of the present invention can allow for providing a mask pattern (on a patterning device) that remains substantially defect-free during use (the mask pattern being protected from pellicle contamination).

[0079] The surface film layer 19 (which may be made of, for example, polysilicon (pSi) or MoSiN) x The pellicle assembly 15 is constructed by depositing the pellicle core layer (made of SiO2) directly on the top (front) of the substrate that will be used to provide the pellicle boundary 17. For example, the stack can be SiO2 / MoSiN x / MoSi2 or SiON / MoSiN x / SiON. The substrate can be, for example, a silicon wafer or an SOI wafer. After depositing the film of pellicle layer 19, the substrate can be selectively etched back (i.e., etched on the backside) to remove the central portion of the substrate and retain only the outer periphery, thereby forming a pellicle boundary 17 to support pellicle layer 19. The manufacturing process will be discussed with reference to the following figures.

[0080] Figure 3A and Figure 3BSchematic illustration of stages in the manufacture of a pellicle assembly according to an alternative manufacturing process to the method of the present invention, illustrated using a cross section of a stack. This method is included to provide a comparison with the method of the present invention.

[0081] A stack 100 is provided, which includes a planar substrate 30 and an optional first sacrificial layer 31. The planar substrate 30 is disposed in an inner region of the stack 100, and the first sacrificial layer 31 is disposed in an outer region of the stack 100. Therefore, the first sacrificial layer 31 preferably substantially surrounds the planar substrate 30. The planar substrate 30 can be, for example, a silicon wafer or an SOI wafer. For example, the planar substrate 30 has a shape such as a square, a circle, or a rectangle. The shape of the planar substrate 30 is not particularly limited, but is most likely a circle because it is the most commonly used shape. The size of the planar substrate 30 is not particularly limited.

[0082] Although the first sacrificial layer 31 is depicted as completely surrounding the planar substrate 30, in some embodiments, the first sacrificial layer 31 may only partially surround the planar substrate 30. In the depicted embodiment, a single sacrificial layer 31 is shown, but it should be understood that there may be layers other than the sacrificial layer 31. The first sacrificial layer may comprise, for example, silicon oxide, silicon nitride, tetraethyl orthosilicate (TEOS), a chemical oxide, or a thermal oxide.

[0083] Stack 100 has a front side and a back side (also referred to as a back side). The front side is defined as the side that is closest to the pellicle layer in later stages of manufacturing. These designations can be made before the pellicle layer is deposited. These terms are used to provide a better understanding of the present invention and to more clearly define the steps in the process. However, the method is also intended to encompass situations in which the stack is flipped or otherwise rotated.

[0084] At least one septum layer 32 is disposed on the first sacrificial layer 31 to define the stack 101. Additionally, while the septum layer 32 is depicted as surrounding the first sacrificial layer 31, in alternative embodiments, the diaphragm layer 32 may only partially surround the first sacrificial layer 31 or be deposited on one side of the stack 100. The septum layer 32 may also be referred to as a septum, a diaphragm layer, a septum core layer, or a diaphragm.

[0085] Although a single pellicle layer 32 is shown, it should be understood that the pellicle layer 32 may include multiple layers. The pellicle layer will include at least one pellicle core layer. The pellicle core layer may include, for example, polycrystalline silicon (pSi) or MoSiN x The pellicle core layer has two main purposes: to provide mechanical strength to the pellicle layer 32 and to allow transmission of radiation (eg, EUV). The pellicle layer 32 may also include at least one additional sacrificial layer (not shown).

[0086] The stack 101 may also include materials from several other layers deposited on the planar substrate 30, layers having various protective functions during the manufacture of the pellicle assembly 15, or layers for enhancing the properties of the pellicle assembly 15, such as resistance to chemicals / environment and / or improved (thermo)mechanical strength and / or reduced imaging impact (e.g. by reducing pellicle reflection of EUV radiation or enhancing reflection of undesirable out-of-band radiation such as DUV or IR radiation).

[0087] Layer stack 102 depicts the step of depositing a first resist 33. First resist 33 can be a positive resist or a negative resist, and the method is not particularly limited to which type of resist is used. First resist 33 is patterned to define portions of layer stack 103 that will be etched in a subsequent etching step. First resist 33 can also be referred to as an etch mask.

[0088] Layer stack 102 may then be etched by any suitable etching means to remove portions of pellicle layer 32 not protected by resist 33, thereby producing layer stack 103. This etching step may also remove portions of sacrificial layer 31 or any additional layers described above, if so designed.

[0089] A protective layer 34 is then applied to the front side of the stack 104 to protect the surface at the front side of the stack 104. Specifically, the protective layer can protect the layers at the front side of the stack 104, particularly the pellicle layer 32, from subsequent etching steps and / or physical contact. The protective layer 34 can comprise a cross-linked poly(para-xylylene) polymer, preferably a Parylene or ProTEK®-type material, or can be an etchant resist, such as a KMPR® and / or TEOS layer. The protective layer 34 is applied as a continuous layer that is substantially free of pores, providing an etchant-impermeable layer. The protective layer 34 is preferably not added to the back side (i.e., the backside) of the stack 104, allowing the etchant to enter the planar substrate 30 and any sacrificial layers 31 via the back side of the stack 104. The optional protective layer 34 is applied to the front side of the stack to protect the surface at the front side of the stack. This allows for a clean deposition surface during subsequent processing steps, prior to depositing the pellicle layer 32. It will be appreciated that the protective layer 34 may not be present in situations where etching of the back side of the stack does not pose a risk of damaging the front side of the stack. Even so, the protective layer 34 is preferred.

[0090] Next, the stack 104 is inverted, and a second resist 35 is deposited on the back side of the stack 105. The second resist 35 can be a positive resist or a negative resist, and the method is not particularly limited to which type of resist is used. The second resist 35 is patterned to define the portion of the stack 105 that will be etched in the subsequent etching step. The second resist 35 can also be referred to as an etch mask. At this stage, the final pellicle boundary region is defined in the process, which is performed after the pellicle layer has been applied.

[0091] At this point in the manufacturing process, contact may occur between the stack 105 and a chuck (not shown). The chuck may include, for example, edge contacts, lift pins, end effectors, and center wheel contacts for holding, moving, and aligning the stack. This contact may occur on the front side of the stack 105 where the pellicle layer 32 is located, thereby presenting a higher risk of damaging the pellicle layer 32.

[0092] The present invention has the advantage of reducing this risk of damage by providing a different manufacturing process, which will be referred to below. Figure 4A and Figure 4B This is described in more detail.

[0093] Figure 4A and Figure 4B The stages of manufacturing a diaphragm assembly according to an embodiment of the present invention are schematically illustrated. A cross-section of the stack is used for illustration. The manufacturing stages are discussed below. Some of the stages and materials described are comparable to those described above and, therefore, will not be described in detail but can be considered equivalent.

[0094] A stack 200 is provided, comprising a planar substrate 30 and a first sacrificial layer 31. An optional protective layer 34 is applied to the front side of the stack 200 to protect the surface at the front side of the stack 201. This allows for a clean deposition surface to be maintained during subsequent processing steps prior to depositing the pellicle layer 32. It should be understood that the protective layer 34 may not be present in situations where etching of the back side of the stack does not pose a risk of damaging the front side of the stack. Even so, the protective layer 34 is preferred.

[0095] The stack 201 is inverted, and a first resist 35 is applied to the rear side (i.e., backside) of the stack 202. Inverting the stack 201 is optional, and the process can be performed without inversion. The resist 35 is patterned to define portions of the stack 202 that will be etched in a subsequent etching step and used to define the pellicle boundary of the final pellicle assembly. The stack 202 can then be etched using any suitable etching means to remove portions of the first sacrificial layer 31 not protected by the resist 35. This is when the pellicle boundary of the final pellicle assembly has been defined and before the material for forming the final pellicle diaphragm has been provided. At this point in the manufacturing process, contact may occur between the stack 202 and a chuck (not shown). This contact may occur on the front side of the stack 202, where the pellicle layer 32 is not present. Therefore, the present invention reduces the higher risk of damage to the pellicle layer 32.

[0096] The resulting stack 203 can then be used for subsequent deposition of the pellicle layer and, therefore, for pellicle assembly fabrication. The resulting stack 203 can also be referred to as the pellicle base 203. The pellicle base 203 can be retained for an extended period of time prior to other fabrication steps without degrading or contaminating the front side of the stack 203. Therefore, if the pellicle layer is damaged during other fabrication steps, fabrication can be restarted from stack 203 (rather than stack 100 in the alternative fabrication process), thereby reducing process learning time.

[0097] After removing the protective layer 34, at least one pellicle layer 32 is disposed on the stack 203 to define a new stack 204. Additionally, while the pellicle layer 32 is depicted as surrounding the entire stack 203, in alternative embodiments, the membrane layer 32 may only partially surround the stack 203 or be deposited on one side of the stack 203. The pellicle layer may also be referred to as a pellicle, a membrane layer, or a membrane.

[0098] Although a single pellicle layer 32 is shown, it should be understood that there may be layers other than the pellicle layer 32. The pellicle layer may include at least one pellicle core layer. The pellicle core layer may comprise, for example, polycrystalline silicon (pSi) or MoSiN x The pellicle core layer has two main purposes: to provide mechanical strength to the pellicle layer 32 and to allow transmission of radiation (eg, EUV).

[0099] In alternative embodiments, the pellicle layer 32 may also include at least one additional layer, a layer having various protective functions during the manufacturing process of the pellicle assembly 15, or a layer for enhancing the properties of the pellicle assembly 15 (such as resistance to chemicals / environment and / or improved (thermo)mechanical strength and / or reduced imaging effects (e.g. by reducing pellicle reflection) and / or increasing emissivity. For example, this may be the case where at least one additional layer (such as a boron or boron-containing layer) may have been provided before the pellicle layer was provided. This will be discussed below and in Figure 5 Some additional embodiments are described in more detail in FIG. 8 .

[0100] After the at least one pellicle layer 32 is deposited, the stack 204 can be further processed to remove portions of material to form the final pellicle assembly 15. Selectively removing portions of the material allows the pellicle assembly 15 to be removed from the surrounding portions of the planar substrate 30 and the sacrificial layer 31. The area for removal is defined using a resist 35. Selectively removing portions of the material further defines the pellicle layer 19 and the pellicle boundary 17. Other processing steps are not particularly relevant to the present invention and, therefore, will not be described in detail herein. Conventional processing steps include, but are not limited to, the application of other resist and / or masking layers, etching steps, and the addition and removal of protective layers.

[0101] Other processing steps may be performed after the diaphragm assembly 15 is removed from the surrounding portion of the planar substrate 30 and the sacrificial layer 31. For example, the diaphragm layer 32 of the diaphragm assembly 15 may include additional sacrificial layers or capping layers as described in detail above. These additional layers may be removed or processed in other processing steps.

[0102] Figure 5 FIG6 and FIG6 depict a preferred embodiment of the present invention, wherein the composition of the pellicle layer 32 is further defined. A feature of the present invention is that depositing the pellicle layer 32 later in the manufacturing process allows for a wider range of materials and layer thicknesses to be used. This is due, in part, to depositing the pellicle layer 32 after selectively removing one or more portions from the backside of the stack, thereby reducing the risk of damage to the pellicle layer.

[0103] In this embodiment, as in Figure 5 As most clearly depicted in FIG, the pellicle layer 32 is deposited. In this embodiment, the pellicle layer includes a pellicle core layer 51, two capping films 52, and a spacer film 53. The pellicle core layer 51 is disposed between the two capping films 52 to form a covered pellicle layer 55. The pellicle core layer may also be referred to as a pellicle or core film. The spacer film 53 is disposed between the covered pellicle layer 55 and the sacrificial layer 31. Preferably, an optional additional spacer layer 56 is disposed between the spacer film 53 and the first capping layer 52. This optional additional spacer layer 56 can serve as an etch stop in a future etching step.

[0104] The pellicle core layer 51 may comprise, for example, polycrystalline silicon (pSi), which has high EUV transmittance and provides strength to the pellicle assembly. The spacer film 53 may be made of, for example, silicon oxide (preferably thermal oxide). The spacer film 53 defines a surface for receiving the other pellicle layers 51 and 52. The additional spacer layer 56 may comprise any material having an etch selectivity compared to silicon oxide (e.g., silicon) or silicon nitride.

[0105] Cap layer 52 can preferably be composed of silicon oxide, such as silicon dioxide (SiO2). Cap layer 52 is preferably a thin film compared to the thickness of the pellicle core layer. Thin SiO2 films can be easily manufactured with a well-defined thickness. A well-defined thickness is beneficial for pellicle manufacturing, as uneven layer thicknesses can lead to over-etching and, consequently, damage to the pellicle core layer 51. Therefore, a layer with a well-defined thickness is desirable.

[0106] like Figure 6A As best shown in FIG, after removing the pellicle assembly 15 from the surrounding portion of the material, the pellicle layer comprises multiple layers. In this preferred embodiment, the pellicle core layer 51 is preferably made of silicon (e.g., polycrystalline silicon (pSi)) or MoSiN x The cap layer 52 is preferably composed of silicon oxide (eg, silicon dioxide (SiO 2 )).

[0107] It is desirable to subsequently remove the cover layer 52, thereby leaving only the skin core layer 51, as in Figure 6B 1. This increases the transmittance of the pellicle assembly 15. The final pellicle assembly includes a pellicle core layer 51 supported on a pellicle boundary 17. The pellicle boundary 17 includes a sacrificial layer 31 disposed between a planar substrate 30 and a spacer film 53, wherein the spacer film 53 is disposed between the sacrificial layer 31 and an optional additional spacer film 56, and the spacer film 56 is adjacent to the cover film 52. The pellicle boundary 17 preferably includes an ordered layer of silicon, silicon dioxide, thermal oxide, optional silicon, and silicon dioxide before being abutted against the pellicle core layer 51.

[0108] While removal of the capping layer 52 may be performed using a variety of methods, removal of the capping layer 52 is preferably performed by etching.

[0109] Figure 7 8 depicts a preferred embodiment of the present invention, wherein the composition of the skin layer 32 is further defined. Many features are comparable to those described above, and therefore they will not be described in further detail.

[0110] In this embodiment, as in Figure 7As most clearly depicted in the figure, the pellicle layer 32 is disposed on the stack. The pellicle layer 32 is deposited on the first sacrificial layer 31. In this embodiment, the pellicle layer 32 includes a pellicle core layer 51, a first cap film 52a, at least one second cap film 52b, and a spacer film 53. Preferably, the pellicle layer 32 may also include a third cap film 52c and a fourth cap film 52d, wherein the second cap film 52b, the third cap film 52c and the fourth cap film 52d include an upper cap layer 52e, which is also called an emitter film. The pellicle core layer 51 is disposed between the first cap film 52a and the emitter film 52e to form a covered pellicle layer 55. The spacer film 53 is disposed between the covered pellicle layer 55 and the sacrificial layer 31. As in the previous embodiment, an optional additional spacer layer 56 may be disposed between the spacer film 53 and the first cap film 52a. The additional spacer layer 56 may serve as an etch stop in a future etching step.

[0111] The pellicle core layer 51 is preferably made of silicon (eg polycrystalline silicon (pSi)) or MoSiN x The spacer film 53 is preferably composed of silicon oxide (e.g., silicon dioxide (SiO2)) or thermal oxide (e.g., heat-treated SiO2). The spacer film 53 defines a flat surface for receiving the other pellicle layers 51, 52a, 52b, 52c, and 52d. The optional additional spacer layer 56 can be composed of any material with an etch selectivity compared to silicon oxide (e.g., silicon) or silicon nitride.

[0112] The first cover layer 52 a is preferably made of silicon oxide, such as silicon dioxide (SiO 2 ). Compared to the thickness of the skin core layer 51 , the first cover layer 52 a is preferably a thin film.

[0113] At least one second cover film 52b may preferably be metallic. In a preferred embodiment, the second cover film 52b, the third cover film 52c, and the fourth cover film 52d may all be metallic. In this preferred embodiment, the second cover film 52b and the fourth cover film 52d are preferably composed of boron or a boron-containing material, and the third cover film 52c is composed of zirconium or a zirconium-containing material. The upper cover film 52e may provide strength and / or increased emissivity to the resulting pellicle assembly 15.

[0114] This embodiment is superior to the prior art because previously, the emissive layer was deposited on the pellicle membrane after removal from the surrounding material, also known as deposition on a freestanding pellicle. Deposition on a freestanding pellicle presents significant manufacturing difficulties. The present invention allows the emissive layer to be deposited before removal, thus avoiding these problems.

[0115] As in Figure 8AAs best seen in the figure, after pellicle assembly 15 is removed from the surrounding portion of the material, the pellicle layer comprises multiple layers, including pellicle core layer 51 disposed between first cover layer 52a and emissive film 52e. It is desirable to subsequently remove first cover layer 52a, leaving only pellicle core layer 51 and emissive film 52e. This increases the emissivity of pellicle assembly 15 while maintaining mechanical strength.

[0116] Can be Figure 8B The final pellicle assembly 15 of this embodiment is most clearly seen in FIG. pellicle assembly 15 includes a pellicle layer 19 supported on a pellicle boundary 17, which includes a cap layer 52a, an optional spacer layer 56, a spacer layer 53, a sacrificial layer 31, and a portion of a planar substrate 30. Optional spacer layer 56 can be further defined as comprising sacrificial layer 31 disposed between planar substrate 30 and spacer membrane 53, wherein spacer membrane 53 is disposed between the sacrificial layer and optional spacer membrane 56, and the spacer membrane is in contact with cap film 52a. Optional spacer layer 56 preferably comprises an ordered layer of silicon, silicon dioxide, thermal oxide, optional silicon, and silicon dioxide prior to being abutted against pellicle core layer 51.

[0117] The pellicle layer 19 can be further defined as including a pellicle core layer 51 preferably made of a silicon-based material (such as pSi or MoSiN) adjacent to the pellicle boundary 17. x ) and an emission layer 52e (preferably metallic), wherein the surface film core layer 51 is arranged between the surface film boundary 17 and the emission film 52e. Figure 9 , for example, at least one additional emissive layer 58 can be added to the pellicle layer. The at least one additional emissive layer 58 can preferably be metallic. For example, the emissive layer can include boron or a boron-containing material, or zirconium or a zirconium-containing material. This additional emissive layer 58 can provide strength and / or increased emissivity to the resulting pellicle assembly 15. The at least one additional emissive layer 58 can be provided after a portion of the planar substrate 30 and sacrificial layer 31 has been removed, but before the pellicle assembly 15 has been completely removed from the surrounding planar substrate 30 and sacrificial layer 31 or the optional protective layer.

[0118] Optional at least one additional emissive layer 58 may be provided to the underside (i.e., rear side or backside) of pellicle layer 19, where the underside is defined as the plane of pellicle layer 19 adjacent to pellicle boundary 17. That is, additional emissive layer 58 may be provided within the region of pellicle layer 19 that is contained within the cavity defined by pellicle boundary 17. Additional emissive layers may also be provided to regions outside of pellicle boundary 17. Figure 9As depicted in the embodiment of FIG, the final pellicle assembly 15 can include a pellicle core layer 51 positioned between two emissive layers 52e, 58. Additionally, the final pellicle assembly 15 can include an emissive layer 58 at least partially surrounding the pellicle boundary 17.

[0119] Although specific reference may be made herein to the use of lithographic equipment in IC manufacturing, it should be understood that the lithographic equipment described herein may have other applications, such as the fabrication of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat panel displays, liquid crystal displays (LCDs), thin-film magnetic heads, and the like. The substrates referred to herein may be processed, before or after exposure, in, for example, a coating and development system (a tool that typically applies a resist layer to a substrate and develops the exposed resist), a metrology tool, and / or an inspection tool. Where applicable, the teachings herein may be applied to these and other substrate processing tools. Furthermore, a substrate may be processed more than once, for example, to form a multi-layer IC, so that the term "substrate" as used herein may also refer to a substrate that already contains multiple processed layers.

[0120] The figures are illustrative and therefore not drawn to scale. This is particularly important when considering, for example, the thickness of a skin layer relative to, for example, a planar substrate.

[0121] Although specific embodiments of the present invention have been described above, it should be appreciated that the present invention may be practiced in other ways than those described. For example, various layers may be replaced with other layers that perform the same functions.

[0122] The above description is intended to be illustrative rather than restrictive. It will therefore be apparent to those skilled in the art that modifications may be made to the invention as described without departing from the scope of the following appended claims.

Claims

1. A diaphragm membrane comprising: a pellicle boundary region for retaining at least a pellicle layer, the pellicle layer forming at least part of the pellicle membrane, wherein the pellicle boundary region is formed by a substrate having a front side and a back side and one or more layers on the back side of the substrate, The surface membrane diaphragm includes MoSiN x A core layer or MoSiN having at least one surface covered with a native oxide layer x core layer.

2. The pellicle membrane according to claim 1, wherein the pellicle layer is composed only of the MoSiN x The core layer is formed without other functional covering layers.

3. The diaphragm membrane according to claim 1, wherein the MoSiN x A core layer or MoSiN having at least one surface covered with a native oxide layer x The core layer is covered by a cap layer. The pellicle membrane according to claim 3 , wherein the cap layer can have a thickness of 0.5 nm to 10 nm. The pellicle membrane according to claim 4 , wherein the cap layer can have a thickness of 1 nm to 5 nm.

6. The pellicle membrane according to claim 1, wherein the MoSiN x The core layer has native oxide layers on both surfaces thereof.

7. The pellicle membrane according to any one of claims 1 to 6, wherein the MoSiN x The core layer has a variation of nitrogen in a material composition equivalent to Mo t Si p N z composition.

8. The pellicle membrane of claim 1, wherein the pellicle layer forming at least a portion of the pellicle membrane is a sacrificial layer. 9 . The diaphragm of claim 8 , wherein the sacrificial layer comprises silicon nitride, silicon oxide, tetraethyl orthosilicate (TEOS), chemical silicon oxide, or thermal silicon oxide. 10 . The pellicle membrane of claim 1 , wherein the pellicle layer forming at least a portion of the pellicle membrane is a spacer layer, the spacer layer serving as an etch stop layer. The diaphragm membrane according to claim 10 , wherein the spacer layer comprises a silicon layer, a silicon dioxide layer or a thermal oxide layer.

12. The pellicle membrane according to claim 1, wherein the pellicle layer forming at least a portion of the pellicle membrane is the MoSiN x core layer.

13. The pellicle membrane of claim 1, wherein the pellicle layer forming at least a portion of the pellicle membrane is an emissive layer. The diaphragm membrane of claim 13 , wherein the emissive layer comprises a metal layer.

15. The pellicle membrane of claim 13, wherein the emissive layer comprises at least a layer of B, Zr, Ru, or Mo.

16. The pellicle membrane according to claim 1, wherein the pellicle membrane comprises a native silicon oxide layer, MoSiN x core layer and MoSi2 cap layer.

17. The pellicle membrane according to claim 1, wherein the pellicle membrane comprises a x Two SiON cap layers on each surface of the core layer.

18. The pellicle diaphragm according to claim 1, wherein the pellicle layer further comprises one of pSi, SiC, MoSi2, or a carbon-based material. 19 . The pellicle membrane according to claim 18 , wherein the carbon-based material comprises a graphene film or a film formed of carbon nanotubes.

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