Method for reducing line edge roughness of EUV photoresist pattern

Abstract

Methods of depositing a conformal carbon-containing film on an EUV photoresist to reduce line edge roughness (LER) are described. An exemplary processing method may include flowing a first precursor over a patterned EUV surface to form a first portion of an initial carbon-containing film on a structure. The methods may include removing a first precursor effluent from the patterned EUV photoresist. A second precursor may then be flowed over the patterned EUV photoresist to react with the first portion of the initial carbon-containing film. These methods may include removing the second precursor effluent from the patterned EUV photoresist. The methods may include etching the substrate to remove a portion of the carbon-containing film and expose a top surface of the patterned surfaces and expose the substrate between the patterned surfaces.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to methods for depositing carbon-based films on nanostructures. Specifically, embodiments of the present disclosure relate to methods for depositing carbon-based films to improve line edge roughness and / or line width roughness (LWR) of patterned EUV photoresists. Background Art

[0002] Photolithography uses a photoresist, which is a light-sensitive film, to transfer a negative or positive image onto a substrate (e.g., a semiconductor wafer). After coating the substrate with the photoresist, the coated substrate is exposed to an activating radiation source, which results in a chemical transformation in the exposed areas of the surface. Depending on the type of photoresist employed, the photoresist-coated substrate is then treated with a developer solution to dissolve or otherwise remove the areas of the coated substrate that were exposed to the radiation or the unexposed areas.

[0003] However, lithographic techniques for producing features having a size of thirty nanometers or less have several disadvantages. For example, given the tight dimensional tolerances typically required in this range, e.g., tolerances on the order of the scale of the molecular components of the resist film, line width variations in resist films produced by such techniques may be too large to be acceptable. Such line width variations may be categorized as line edge roughness (LER) and / or line width roughness (LWR).

[0004] Line edge roughness and line width roughness reflect line width fluctuations that can lead to variations in device characteristics. As the critical dimensions of integrated circuits continue to shrink, line width fluctuations will play an increasingly important role in the critical dimension (CD) error budget of lithography. Several suspected sources of LER and LWR in resist patterns include master mask quality, aerial image quality, and resist material properties.

[0005] Extreme ultraviolet (EUV) lithography (EUVL) shows promise as a next-generation lithography technology. Current key challenges for EUV technology include photoresist roughness. Currently, plasma post-treatment is used to smooth the photoresist surface, but this plasma post-treatment can damage the photoresist pattern or reduce the photoresist height.

[0006] Thus, there continues to be a need in the art for alternative methods of reducing the line edge roughness of EUV photoresist patterns. Summary of the invention

[0007] One or more embodiments of the present disclosure relate to a method for depositing a carbon-containing film. The method includes: flowing a first precursor over an EUV photoresist comprising a patterned surface to form a first portion of a carbon-containing film on the patterned surface, the first precursor comprising a first reactive group; removing a first precursor effluent comprising the first precursor from the EUV photoresist; flowing a second precursor comprising a second reactive group over the EUV photoresist to react with the first reactive group to conformally form a carbon-containing film on the patterned surface; and removing a second precursor effluent comprising the second precursor from the EUV photoresist.

[0008] Another embodiment of the present disclosure is directed to a method for depositing a carbon-containing film. The method includes: flowing a first precursor having a general formula R 1 -(X) n , where R 1 Contains one or more of the following: alkyl, alkenyl, aryl, aromatic group, and cycloalkyl, X n The method comprises one or more of the following: a hydroxyl group, an aldehyde group, a ketone group, an acid group, an amine group, an isocyanate group, a thiocyanate group, and an acyl chloride group, and n is an integer in the range of from 1 to 6, wherein a first precursor reacts with a reactive group on a patterned surface to form a first portion of a carbon-containing film; removing a first precursor effluent comprising the first precursor from an EUV photoresist; flowing a second precursor over the EUV photoresist, the second precursor having a general formula R 2 -(Y) n , where R 2 Contains one or more of the following: an alkyl group, an alkenyl group, an aryl group, an aromatic group, and a cycloalkyl group, Y n comprising one or more of: a hydroxyl group, an aldehyde group, a ketone group, an acid group, an amine group, an isocyanate group, a thiocyanate group, and an acyl chloride group, and n is an integer in the range from 1 to 6, wherein a second precursor reacts with the first portion to form a conformal carbon-containing film; removing a second precursor effluent comprising the second precursor from the EUV photoresist; and etching the EUV photoresist to remove a portion of the carbon-containing film from a top surface of the patterned surface.

[0009] Another embodiment of the present disclosure relates to a method for reducing the line edge roughness (LER) of an EUV photoresist. In one or more embodiments, the method includes molecular layer deposition of a carbon-containing film on a patterned surface of the EUV photoresist, wherein the molecular layer deposition includes: flowing a first precursor over the EUV photoresist including the patterned surface to form a first portion of the carbon-containing film on the patterned surface, the first precursor including a first reactive group; removing a first precursor effluent including the first precursor from the EUV photoresist; flowing a second precursor including a second reactive group over the EUV photoresist to react with the first reactive group to conformally form a carbon-containing film on the patterned surface; and removing a second precursor effluent including the second precursor from the EUV photoresist, wherein the carbon-containing film is formed on the sidewalls of the EUV photoresist and reduces the line edge roughness (LER). BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to be able to understand in detail the manner in which the above-mentioned features of the present disclosure are used, a more specific description of the present disclosure briefly summarized above may be made with reference to embodiments, some of which are illustrated in the accompanying drawings. However, it will be noted that the accompanying drawings illustrate only common embodiments of the present disclosure and are not to be considered limiting of its scope, as the present disclosure may admit of other equally effective embodiments. The embodiments as described herein are illustrated by way of example and are not limited in the drawings of the accompanying drawings, in which like references indicate similar components.

[0011] Figure 1A illustrates a cross-sectional view of a substrate according to one or more embodiments;

[0012] Figure 1B illustrates a cross-sectional view of a substrate according to one or more embodiments;

[0013] Figure 1C illustrates a cross-sectional view of a substrate according to one or more embodiments;

[0014] Figure 1D illustrates a cross-sectional view of a substrate according to one or more embodiments; and

[0015] Figure 2 A process flow diagram illustrating a method of depositing a film on a substrate according to one or more embodiments. DETAILED DESCRIPTION

[0016] Before describing several exemplary embodiments of the present invention, it is to be understood that the present invention is not limited to the details of construction or process steps set forth in the following description. The present invention is capable of other embodiments and of being practiced or carried out in various ways.

[0017] As used herein, the term "about" means approximately or nearly, and in the context of a stated numerical value or range means a variation of ±15% or less of the value. For example, values ​​that differ by ±14%, ±10%, ±5%, ±2%, or ±1% will satisfy the definition of about.

[0018] As used in this specification and the appended claims, the term "substrate" or "wafer" refers to a surface, or portion of a surface, on which a process is performed. As will also be understood by those skilled in the art, reference to a substrate may also refer to only a portion of a substrate unless the context clearly indicates otherwise. In addition, reference to depositing on a substrate may mean both a bare substrate and a substrate having one or more films or features deposited or formed thereon.

[0019] As used herein, "substrate" or "substrate surface" refers to any portion of a substrate on which film processing is performed or a portion of a material surface formed on a substrate. For example, depending on the application, the substrate surface on which processing can be performed includes materials such as silicon, silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other material, such as metals, metal nitrides, metal alloys, and other conductive materials. Substrates include, but are not limited to, semiconductor wafers. The substrate may be exposed to a pretreatment process to polish, etch, reduce, oxidize, hydroxylate, anneal, UV cure, electron beam cure, and / or bake the substrate surface. In addition to processing directly on the surface of the substrate itself, in the present disclosure, as disclosed in more detail below, any film processing step disclosed may also be performed on an underlying layer formed on the substrate, and the term "substrate surface" is intended to include such an underlying layer as indicated by the context. Thus, for example, in the case where a film / layer or a portion of a film / layer has been deposited onto the substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate. The substrate may have various sizes, such as 200 mm or 300 mm diameter wafers, and rectangular or square panels. In some embodiments, the substrate comprises a rigid discrete material.

[0020] The term “on” indicates that there is direct contact between components. The term “directly on” indicates that there is direct contact between components without intervening components.

[0021] As used herein, "extreme UV," "EUV," or the like refers to radiation in the approximate range of 10 nm to 124 nm. In some embodiments, EUV radiation (also referred to as EUV light) is in the range of 10 nm to 15 nm. In one or more embodiments, EUV light at a wavelength of about 13.5 nm is employed.

[0022] As used in this specification and the appended claims, the terms "precursor," "reactant," "reactive gas," and the like are used interchangeably to refer to any gas species that can react with a substrate surface.

[0023] As used in this specification and the appended claims, the terms "reactive compound," "reactive gas," "reactive substance," "precursor," "processing gas," and the like are used interchangeably to mean a substance having a species capable of reacting with a substrate or a material on the substrate in a surface reaction (e.g., chemisorption, oxidation, reduction, cycloaddition). The substrate, or portion of the substrate, is sequentially exposed to two or more reactive compounds that are introduced into a reaction zone of a processing chamber.

[0024] Carbon-containing materials can be used in several structures and processes in semiconductor device manufacturing, including as mask materials, etch-resistant materials, and trench fill materials, among other applications. More specific examples of applications for carbon-containing materials include forming thermal implant hard masks, metal gate (MG)-cut hard masks, metal gate manufacturing, and reverse tone patterning, self-aligned patterning, and the like. One or more embodiments include forming these carbon-containing materials as a film on a patterned EUV photoresist using molecular layer deposition (MLD).

[0025] Embodiments of the present disclosure provide methods for depositing films (e.g., carbon-containing films) on features having small dimensions. Some embodiments advantageously provide conformal films to completely cover features. Other embodiments advantageously provide conformal films that completely or partially cover features. The carbon-containing films of one or more embodiments have high conformality. In one or more embodiments, the conformal carbon-containing film is deposited on EUV photoresist.

[0026] Embodiments of the present technology include molecular layer deposition (MLD) methods and systems for forming carbon-containing materials on patterned photoresists. An exemplary MLD method may include providing a first deposition precursor to a surface of a patterned EUV photoresist, wherein the precursor forms a first layer (e.g., a first monolayer) on a mandrel surface. During or after forming the first layer, unbound deposition effluent (which may include unbound molecules of the first deposition precursor) is removed from a processing area that exposes the patterned EUV photoresist. A second deposition precursor may then be introduced into the patterned EUV photoresist, wherein molecules of the second deposition precursor bind to reactive moieties on the first layer to form a second layer (e.g., a second monolayer) on the patterned surface. During or after forming the second layer, unbound deposition effluent (which may include unbound molecules of the second deposition precursor) is removed from the processing area. The patterned EUV photoresist now has a layer of carbon-containing material bound to the patterned mandrel surface of the EUV photoresist. Additional compound layers of the first and second layers may be accumulated on the deposited layer until the number of accumulated compound layers reaches the desired thickness of the carbon-containing material on the patterned surface of the EUV photoresist. The compound layer may then be annealed, or plasma treated to form a carbon-containing material on the surface of the EUV photoresist.

[0027] One or more embodiments advantageously provide solutions to problems with conventional methods of forming carbon-containing materials on EUV photoresists. For example, the present technology forms carbon-containing materials with significantly fewer voids, fractures, and other physical defects than carbon-containing materials formed using spin-on-carbon (SOC) and flowable chemical vapor deposition (FCVD) methods. The present technology can also form carbon-containing materials with higher density and lower porosity than materials formed using SOC and FCVD. When the deposited material is processed to form the final material, the high hydrogen levels found in many SOC and FCVD precursors lead to high shrinkage levels. Shrinkage of up to 50% by volume after processing is not uncommon for deposited SOC and FCVD materials, which creates gaps, features, and voids in the processed material, as well as stresses on substrate features in contact with the material. The present technology produces carbon-containing materials with less than 10% shrinkage of the deposited material (e.g., 5-10% shrinkage by volume, less than about 5% shrinkage by volume).

[0028] One or more embodiments advantageously provide solutions to problems with conventional plasma deposition methods for forming carbon-containing materials on EUV photoresists. Conventional plasma deposition methods, such as plasma enhanced chemical vapor deposition (PECVD) and high density plasma chemical vapor deposition (HDPCVD), often produce ion sputtering that causes damage to substrate features on EUV photoresists and can also produce re-sputtered ions and other species that can cause defects in the deposited carbon-containing material. In addition, they often deposit material unevenly in and around substrate features, thereby producing voids in and around substrate grooves and steps, and producing uneven surfaces in flat substrate areas. The present technology can form carbon-containing materials with high conformality levels and high aspect ratios (e.g., AR of 10:1 or greater) in narrow substrate features (e.g., dimensions less than about 25 nm in width) without requiring plasma that can damage substrate features during deposition.

[0029] Embodiments of the present disclosure are described by way of drawings, which illustrate devices (e.g., transistors) and processes for forming semiconductor structures according to one or more embodiments of the present disclosure. The processes shown are merely illustrative of possible uses of the disclosed processes, and those skilled in the art will recognize that the disclosed processes are not limited to the applications shown.

[0030] Figures 1A to 1D A cross-sectional view of EUV photoresist processed according to methods of one or more embodiments is illustrated. Figure 2 2 is a process flow diagram of a method 200 for depositing a carbon-containing film according to one or more embodiments. Figures 1A to 1D and Figure 2 In one or more embodiments, a patterned EUV photoresist is provided at operation 202. As used in this specification and the appended claims, the term "provided" means that the substrate is available for processing (eg, positioned in a processing chamber). Figure 1A is based on Figure 2 A cross-sectional view 100 of a method of processing EUV photoresist. Figure 1B 105 is a top view of EUV photoresist.

[0031] See also Figure 1A and Figure 1BIn one or more embodiments, the EUV photoresist 102 includes a patterned surface 104. In one or more embodiments, the patterned surface 104 includes one or more of a photoresist, a mandrel, a groove, a via, a hole, and the like. In a specific embodiment, the patterned surface 104 includes a patterned EUV photoresist having a photoresist mandrel. The photoresist can be patterned to form the patterned surface 104 using EUV radiation and a developer for exposing portions of the photoresist and leaving a residue of the photoresist. As used herein, "photoresist" refers to any photosensitive material used in such processes for photolithography and photoengraving to form a patterned coating on a surface. The photoresist patterned surface 104 (mandrel) can be formed by one or more of EUV lithography, or deep ultra-violet (DUV) electron beam lithography.

[0032] In one or more embodiments, the patterned surface 104 includes a top surface 110, a first sidewall 109, and a second sidewall 111. In one or more embodiments, as in Figure 1B In the middle figure, the patterned surface 104 includes a plurality of surface unevenness 199, so that the patterned surface 104 is rough and not smooth. In one or more embodiments, the patterned surface 104 (also referred to as the photoresist mandrel) may have pattern variations along the line edges (surface unevenness 199), resulting in line width roughness (LWR) and line edge roughness (LER), which may cause layer-to-layer variations during pattern transfer. Without intending to be bound by theory, in one or more embodiments, a thin molecular layer deposition (MLD) carbon-based film 106 is coated on the photoresist pattern of the patterned surface 104 to smooth the photoresist mandrel surface to reduce LWR and LER.

[0033] Those skilled in the art will recognize that although not shown in the illustration for ease of illustration, Figure 1A and Figure 1C As shown in FIG. 1 , surface unevenness 199 exists in the patterned surface 104 .

[0034] As one skilled in the art will appreciate, there may be more than one patterned surface 104 (mandrels) on the EUV photoresist 102. In some embodiments, there are at least two patterned surfaces 104 separated by features 101.

[0035] In one or more embodiments, the patterned surface 104 on which the carbon-containing material is formed may include a material in which one or more features 101 may be formed. The features 101 may be characterized by any shape or configuration according to the present technology. In some embodiments, the features 101 may be or include a trench structure, a via structure, or a hole formed in a substrate. Although the features 101 may be characterized by any shape or size, in some embodiments, the substrate features 101 may be characterized by a higher aspect ratio, or a ratio of the depth across the feature to the width across the feature 101. For example, in some embodiments, the substrate features may be characterized by an aspect ratio greater than or equal to 5:1, and may be characterized by an aspect ratio greater than or equal to 10:1, greater than or equal to 15:1, greater than or equal to 20:1, greater than or equal to 25:1, greater than or equal to 30:1, greater than or equal to 40:1, greater than or equal to 50:1, or greater. Furthermore, feature 101 may be characterized by including a narrow width or diameter across the feature between two sidewalls, such as a critical dimension in a range from 5 nm to 500 nm, or in a range from 10 nm to 200 nm, or in a range from 20 nm to 100 nm.

[0036] In one or more embodiments, the distance d1 between each of the patterned surfaces 104 is in a range from 5 nm to 500 nm, or in a range from 10 nm to 200 nm, or in a range from 20 nm to 100 nm.

[0037] Figure 1C is based on Figure 2 A cross-sectional view 100 of a method of processing EUV photoresist. Figure 1D is a top view 105 of EUV photoresist. Figure 1C and Figure 1D , and see Figure 2 In one or more embodiments, at operation 204, the EUV photoresist 102 and the patterned surface 104 may be exposed to a pre-treatment process to polish, coat, dope, etch, reduce, oxidize, hydroxylate, anneal, UV cure, e-beam cure, and / or bake the substrate as appropriate.

[0038] In one or more embodiments, the carbon-containing film 106 is formed substantially conformally over the EUV photoresist 102 and the patterned surface 104. As used herein, a "substantially conformal" layer refers to a layer where the thickness is approximately the same throughout the layer, for example, on the top, middle, and bottom of the sidewalls and on the bottom of the feature 101. A substantially conformal layer has a thickness variation of less than or equal to about 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or 0.5%.

[0039] refer to Figure 2At operation 206 , a first type of precursor is introduced / flowed into the substrate processing region of the processing chamber and over the substrate surface. The first precursor strongly binds to the EUV photoresist 102 and the patterned surface 104 .

[0040] In one or more embodiments, the first precursor may be a carbon-containing precursor having at least two reactive groups that can form bonds with groups attached to the EUV photoresist 102 and the patterned surface 104. The molecules of the first precursor react with the surface groups of the EUV photoresist 102 and the patterned surface 104 to form bonds linking the first precursor molecules to the EUV photoresist 102 and the patterned surface 104. The reaction between the first precursor molecules and the groups on the EUV photoresist 102 and the patterned surface 104 continues until most or all of the surface groups are bound to the reactive groups on the first precursor molecules. A first portion of the carbon-containing film 106 is formed that blocks further reactions between the first precursor molecules in the first precursor effluent and the substrate.

[0041] The first precursor may include any suitable precursor known to those skilled in the art. In one or more embodiments, the first precursor may have a general formula R 1 -(X) n , wherein n is an integer in the range from 1 to 6, and R 1 Contains one or more of the following: alkyl, alkenyl, aryl, aromatic group, and cycloalkyl. n Contains one or more of the following: hydroxyl group, aldehyde group, ketone group, acid group, amine group, isocyanate group, thiocyanate group, and acyl chloride group.

[0042] Unless otherwise indicated, the terms "lower alkyl", "alkyl", or "alk" as used herein alone or as part of another group include straight and branched hydrocarbons containing 1 to 20 carbons, or 1 to 10 carbon atoms in the normal chain, such as methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, isobutyl, pentyl, hexyl, isohexyl, heptyl, 4,4-dimethylpentyl, octyl, 2,2,4-trimethyl-pentyl, nonyl, decyl, undecyl, dodecyl, various branched isomers thereof, and the like. Such groups may optionally include up to 1 to 4 substituents. Alkyl groups may be substituted or unsubstituted.

[0043] Such alkyl groups may optionally include up to 1 to 4 substituents, such as halogen, e.g., F, Br, Cl, or I, or CF3, alkyl, alkoxy, aryl, aryloxy, aryl (aryl) or diaryl, aralkyl, arylalkoxy, alkenyl, cycloalkyl, cycloalkylalkyl, cycloalkylalkoxy, amine, hydroxyl, hydroxyalkyl, acyl, heteroaryl, heteroaryloxy, heteroarylalkyl, heteroarylalkoxy, aryloxyalkyl, alkylthio, arylalkylthio, aryloxyaryl, alkylamide, alkylamide, arylcarbonylamino, nitro, cyano, thiol, haloalkyl, trihaloalkyl, and / or alkylthio, and the like. In one or more embodiments, R 1 Independently selected from C 1-20 In other embodiments, R 1 It is from C 1-12 alkyl.

[0044] As used herein, the term "alkene" or "alkenyl" or "lower alkenyl" refers to a straight or branched chain radical of 2 to 20 carbons or 2 to 12 carbons and 1 to 8 carbons in the normal chain, which includes one to six double bonds in the normal chain, such as vinyl, 2-propenyl, 3-butenyl, 2-butenyl, 4-pentenyl, 3-pentenyl, 2-hexenyl, 3-hexenyl, 2-heptenyl, 3-heptenyl, 4-heptenyl, 2 ... -heptenyl, 3-octenyl, 3-nonenyl, 4-decenyl, 3-undecenyl, 4-dodecenyl, 4,8,12-tetradecatrienyl, and the like, and optionally substituted with 1 to 4 substituents, i.e., halogen, haloalkyl, alkyl, alkoxy, alkenyl, alkynyl, aryl, aralkyl, cycloalkyl, amino, hydroxy, heteroaryl, cycloheteroalkyl, alkanoyl, alkylamido, alkylamido, arylcarbonyl-amino, nitro, cyano, thiol, alkylthio, and / or any alkyl substituent described herein.

[0045] As used herein, the term "alkynyl" or "lower alkynyl" refers to a straight or branched chain radical of 2 to 20 carbons, or 2 to 12 carbons, or 2 to 8 carbons in the normal chain, which includes a triple bond in the normal chain, such as 2-propynyl, 3-butynyl, 2-butynyl, 4-pentynyl, 3-pentynyl, 2-hexynyl, 3-hexynyl, 2-heptynyl, 3-heptynyl, 4-heptynyl, 3-octynyl, 3-nonynyl, 4 4-decynyl, 3-undecynyl, 4-dodecynyl, and the like, and optionally substituted with 1 to 4 substituents, i.e., halogen, haloalkyl, alkyl, alkoxy, alkenyl, alkynyl, aryl, aralkyl, cycloalkyl, amino, heteroaryl, cycloheteroalkyl, hydroxy, alkanoylamino, alkanoylamido, arylcarbonylamino, nitro, cyano, thiol, and / or alkylthio, and / or any alkyl substituent described herein.

[0046] The term "halogen" or "halo" as used herein alone or as part of another group refers to chlorine, bromine, fluorine, and iodine as well as CF3.

[0047] As used herein, the term "aryl" refers to monocyclic and bicyclic aromatic groups containing 6 to 10 carbons in the ring portion (such as phenyl, biphenyl or naphthyl, including 1-naphthyl and 2-naphthyl) and may optionally include 1 to 3 additional rings fused to a carbocyclic or heterocyclic ring (such as an aryl, cycloalkyl, heteroaryl, or cycloheteroalkyl ring). The aryl group may optionally be substituted with 1, 2, or 3 substituents, for example, hydrogen, halogen, haloalkyl, alkyl, haloalkyl, alkoxy, haloalkoxy, alkenyl, trifluoromethyl, trifluoromethoxy, alkynyl, and the like, through available carbon atoms.

[0048] Specific examples of the first precursor include, but are not limited to, one or more of the following: terephthalaldehyde, phenylenediamine, ethylenediamine, hexamethylenediamine, terephthaloyl chloride, 1,3,5-benzene trimellitic acid trichloride, pyromellitic dianhydride, benzene-1,3,5-tricarbaldehyde, 1,4-phenylene diisocyanate, 4,4'-oxydianiline, tris(2-aminoethyl)amine, and the like.

[0049] In one or more embodiments, the rate of formation of the first portion of the carbon-containing film may depend on the temperature of the substrate and the temperature of the deposition precursor flowing into the substrate processing region. Exemplary substrate temperatures during the forming operation may be greater than or equal to 50°C, greater than or equal to 60°C, greater than or equal to 70°C, greater than or equal to 80°C, greater than or equal to 90°C, greater than or equal to 100°C, greater than or equal to 110°C, greater than or equal to 120°C, greater than or equal to 130°C, greater than or equal to 140°C, greater than or equal to 150°C, or higher. By maintaining an elevated substrate temperature, such as greater than or about 100°C, in some embodiments, an increased number of nucleation sites may be available along the EUV photoresist 102 and the patterned surface 104, which may improve formation and reduce void formation by improving coverage at each location. In one or more embodiments, the temperature is in the range from 60°C to 150°C, or in the range from 25°C to 300°C.

[0050] The first precursor effluent may be maintained in the substrate processing region for a period of time to almost or completely form the first portion of the carbon-containing film 106. The precursors may be delivered in alternating pulses to grow the material. In some embodiments, the pulse time of either or both of the first and second precursors may be greater than or equal to 0.1 seconds, greater than or equal to 1 second, greater than or equal to 2 seconds, greater than or equal to 3 seconds, greater than or equal to 4 seconds, greater than or equal to 5 seconds, greater than or equal to 10 seconds, greater than or equal to 20 seconds, greater than or equal to 40 seconds, greater than or equal to 60 seconds, greater than or equal to 80 seconds, greater than or equal to 100 seconds, or greater.

[0051] refer to Figure 2 In operation 208, the first precursor is purged or removed from the substrate processing area after forming the first portion 110 of the carbon-containing film 106. The effluent of the first precursor can be removed by pumping it out of the substrate deposition area for a time period ranging from about 10 seconds to about 100 seconds. Additional exemplary time ranges may include about 20 seconds to about 50 seconds, and 25 seconds to about 45 seconds, as well as other exemplary time ranges. However, in some embodiments, the increased purge time may begin to remove reactive sites, which may reduce uniform formation. Thus, in some embodiments, the purge may be performed for less than or equal to 60 seconds and may be performed for less than or equal to 50 seconds, less than or equal to 40 seconds, less than or equal to 30 seconds, or less. In some embodiments, a purge gas may be introduced into the substrate processing area to assist in removing the effluent. Exemplary purge gases include argon (Ar), helium (He), and nitrogen (N2), as well as other purge gases.

[0052] See also Figure 2 At operation 210, a second type of precursor reacts with the first precursor to form a second portion of the carbon-containing film 106. The second precursor may advantageously have a functional group on one end that increases the thickness of the carbon-containing film 106.

[0053] In one or more embodiments, the second precursor may be a carbon-containing precursor having at least two reactive groups that can form bonds with unreacted reactive groups of the first precursor, which form a first portion of the carbon-containing film 106. The molecules of the second precursor react with the unreacted reactive groups of the first precursor to form bonds linking the second precursor molecules to the first precursor molecules. The reaction between the second and first precursor molecules continues until most or all of the unreacted reactive groups on the first precursor molecules have reacted with the second precursor molecules. A second portion of the carbon-containing film 106 of the deposited precursor is formed that blocks further reaction between the second precursor molecules in the second precursor effluent and the first portion of the carbon-containing film 106.

[0054] The second precursor may include any suitable precursor known to those skilled in the art. In one or more embodiments, the second precursor may have the general formula R 2 -(Y) n , wherein n is an integer in the range from 1 to 6, and R 2 Contains one or more of the following: alkyl, alkenyl, aryl, aromatic group, and cycloalkyl. In one or more embodiments, R 2 Independently selected from C 1-20 In other embodiments, R 2 It is from C 1-12 Alkyl. nContains one or more of the following: hydroxyl group, aldehyde group, ketone group, acid group, amine group, isocyanate group, thiocyanate group, and acyl chloride group.

[0055] Without intending to be bound by theory, it is believed that the second precursor includes a reactive group that can form a covalent bond with a reactive group of the first precursor.

[0056] Specific examples of the second precursor include, but are not limited to, one or more of the following: terephthalaldehyde, phenylenediamine, ethylenediamine, hexamethylenediamine, terephthaloyl chloride, 1,3,5-benzene trimellitic acid trichloride, pyromellitic dianhydride, benzene-1,3,5-tricarbaldehyde, 1,4-phenylene diisocyanate, 4,4'-oxydianiline, tris(2-aminoethyl)amine, and the like.

[0057] See also Figure 2 In one or more embodiments, method 200 also includes operation 212 for purging or removing the second precursor effluent from the substrate processing region after forming the second portion of the carbon-containing film 106. The effluent can be removed by pumping it out of the substrate deposition region for a time period ranging from about 10 seconds to about 100 seconds. Additional exemplary time ranges may include about 20 seconds to about 50 seconds, and 25 seconds to about 45 seconds, as well as other exemplary time ranges. In some embodiments, a purge gas may be introduced into the substrate processing region to assist in removing the effluent. Exemplary purge gases include argon, helium, and nitrogen, as well as other purge gases.

[0058] In one or more embodiments, the formation rate of the second portion of the carbon-containing film 106 may also depend on the pressure of the second precursor effluent in the substrate processing region. Exemplary effluent pressures in the substrate processing region may vary from about 1 mTorr to about 20 Torr. Additionally, exemplary ranges include 5 Torr to 15 Torr, and 9 Torr to 12 Torr, among other exemplary ranges.

[0059] refer to Figure 2In one or more embodiments of the method 200, there is a determination / decision point 214: whether a target thickness of the deposited carbon-containing film 106 on the EUV photoresist 102 and the patterned surface 104 is reached after one or more cycles of forming the carbon-containing film 106 (e.g., after forming the first and second portions of the compound layer). If the target thickness of the deposited carbon-containing film 106 has not been reached, another cycle of forming the first and second portions of the carbon-containing film 106 is performed. If the target thickness of the deposited carbon-containing film 106 has been reached, another cycle for forming another carbon-containing film 106 is not started. An exemplary number of cycles for forming the carbon-containing film may include 1 cycle to 2000 cycles. Additional exemplary ranges of the number of cycles may include 50 cycles to 1000 cycles, and 100 cycles to 750 cycles, among other exemplary ranges.

[0060] Thus, in one or more embodiments, the method 200 further includes depositing at least one additional carbon-containing film on the initial carbon-containing film, wherein the initial carbon-containing film and the at least one additional carbon-containing film form the carbon-containing film 106 on the metal surface of the substrate.

[0061] In one or more embodiments, the carbon-containing film 106 can have any suitable thickness. In one or more embodiments, the thickness of the carbon-containing film 106 is in a range from 0.1 nm to 50 nm, or in a range from 0.1 nm to 200 nm, or in a range from 1 nm to 20 nm, or in a range from 1 nm to 10 nm, or in a range from 3 nm to 10 nm, or in a range from 1 nm to 5 nm.

[0062] As in Figure 1D As shown in FIG. 1 , a carbon-containing film 106 may be formed on the patterned surface 104 so as to fill the surface asperities 199 of the patterned surface 104 , thereby reducing the line edge roughness (LER) of the patterned surface 104 and forming a smooth surface.

[0063] In one or more embodiments, the distance d2 between each of the patterned surfaces 104 after depositing the carbon-containing film is in a range from 5 nm to 500 nm, or in a range from 10 nm to 200 nm, or in a range from 20 nm to 100 nm. In one or more embodiments, the distance d2 between each of the patterned surfaces 104 after depositing the carbon-containing film 106 may be less than the distance d1 between each of the patterned surfaces 104 before depositing the carbon-containing film 106.

[0064] exist Figure 2In the embodiment illustrated in the method 200 of , the deposited carbon-containing film 106 on the EUV photoresist 102 and the patterned surface 104 may be optionally post-processed at operation 216. The optional post-processing operation 216 may be, for example, a process for modifying film properties (e.g., annealing or plasma treatment) or an additional film deposition process for growing additional films (e.g., additional ALD or CVD processes). In some embodiments, the optional post-processing operation 216 may be a process for modifying the properties of the deposited film. In some embodiments, the optional post-processing operation 216 includes annealing the carbon-containing film 106. In some embodiments, the annealing is performed at a temperature in the range of about 300°C, 400°C, 500°C, 600°C, 700°C, 800°C, 900°C, or 1000°C. The annealing environment of some embodiments includes one or more of the following: an inert gas (e.g., molecular nitrogen (N2), argon (Ar)) or a reducing gas (e.g., molecular hydrogen (H2) or ammonia (NH3)) or an oxidant, such as but not limited to oxygen (O2), ozone (O3), or peroxide. Annealing can be performed for any suitable length of time. In some embodiments, the carbon-containing film is annealed for a predetermined time in the range of about 15 seconds to about 90 minutes, or in the range of about 1 minute to about 60 minutes. In some embodiments, annealing the deposited carbon-containing film increases density, reduces resistivity, and / or increases purity of the film.

[0065] In other embodiments, at operation 216, the carbon-containing film 106 may be subjected to an etching process to remove a portion of the carbon-containing film 106 and expose the top surface 110 of the patterned surface 104 and a portion of the EUV photoresist 102 exposed between the patterned surfaces 104. The etching process may be any suitable etching process known to those skilled in the art. In one or more embodiments, the etching process is a dry etching process, such as plasma etching or reactive ion etching.

[0066] Some embodiments of the present disclosure relate to electronic devices including nanostructures having a carbon-containing film 106 as a layer remaining after an etching process removes the carbon-containing film 106 from the bottom portion of the trench between the structures. The carbon-containing film 106 can be used as an etching protection layer or an anti-etching layer for the sidewalls of the nanostructures. In some embodiments, when etching is not performed, the carbon-containing film 106 is used as a liner material. In some embodiments, when formed on the sidewalls of the EUV photoresist pattern, the carbon-containing film 106 is used as a spacer to reduce line edge roughness (LER) and light width roughness (LWR).

[0067] In some embodiments, the processing area is in a modular system comprising multiple chambers that perform various functions, including substrate centering and orientation, degassing, annealing, deposition and / or etching. According to one or more embodiments, the modular system includes at least a first processing chamber and a central transfer chamber. The central transfer chamber can accommodate a robot that can carry substrates between and in the processing chamber and the load lock chamber. The transfer chamber is typically maintained under vacuum conditions and provides an intermediate stage for carrying substrates from one chamber to another and / or to a load lock chamber located at the front end of the cluster tool. However, for the purpose of performing specific steps of the process as described herein, the actual arrangement and combination of chambers may be changed. Other processing chambers that may be used include, but are not limited to, cyclic layer deposition (CLD), atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etching, pre-cleaning, chemical cleaning, thermal treatments such as RTP, plasma nitridation, degassing, orientation, hydroxylation and other substrate processes. By performing the process in the processing chamber of the modular system, surface contamination of the substrate with atmospheric impurities can be avoided without oxidation before deposition of subsequent films.

[0068] According to one or more embodiments, the substrate remains under vacuum or "load lock" conditions and is not exposed to ambient air when moving from one chamber to the next. The transfer chamber is thus under vacuum and "pumped down" at vacuum pressure. An inert gas may be present in the processing chamber or the transfer chamber. In some embodiments, the inert gas is used to purge or remove some or all of the reactants (e.g., reactants). According to one or more embodiments, the inert gas is injected at the outlet of the processing chamber to prevent reactants (e.g., reactants) from moving from the processing chamber to the transfer chamber and / or additional processing chambers. Thus, the flow of the inert gas forms a curtain at the outlet of the chamber.

[0069] Substrates may be processed in a single substrate deposition chamber, where a single substrate is loaded, processed, and unloaded before another substrate is processed. Similar to the conveyor system, substrates may also be processed in a continuous manner, where multiple substrates are independently loaded into a first portion of the chamber, moved through the chamber, and unloaded from a second portion of the chamber. The shape of the chamber and associated conveyor system may form a straight path or a curved path. Additionally, the processing chamber may be a turntable, where multiple substrates are moved around a central axis throughout the turntable path and exposed to deposition, etching, annealing, cleaning, etc. processes.

[0070] During processing, the substrate may be heated or cooled. Such heating or cooling may be achieved by any suitable means, including but not limited to changing the temperature of the substrate support and flowing a heated or cooled gas to the substrate surface. In some embodiments, the substrate support includes a heater / cooler that can be controlled to change the substrate temperature conductively. In one or more embodiments, the gas (reactive gas or inert gas) employed is heated or cooled to locally change the substrate temperature. In some embodiments, the heater / cooler is located in a chamber adjacent to the substrate surface to change the substrate temperature convectively.

[0071] The substrate may also be fixed or rotated during processing. A rotating substrate may be rotated continuously or in discrete steps (about the substrate axis). For example, the substrate may be rotated throughout the process, or the substrate may be rotated a small amount between exposures to different reactive or purge gases. Rotating the substrate during processing (continuously or in steps) may help produce a more uniform deposition or etch by minimizing the effects of local variability, such as gas flow geometry.

[0072] In a spatial ALD process, reactive gases flow into different processing areas within a processing chamber. Different processing areas are separated from adjacent processing areas so that the reactive gases do not mix. The substrate can be moved between processing areas to expose the substrate to reactive gases separately. During the movement of the substrate, different parts of the substrate surface, or materials on the substrate surface, are exposed to two or more reactive gases, so that any given point on the substrate is not substantially exposed to more than one reactive gas at the same time. As will be understood by those skilled in the art, there is the possibility that a small portion of the substrate may be exposed to multiple reactive gases at the same time due to the diffusion of the gases in the processing chamber, and is not intended to be exposed simultaneously unless otherwise specified.

[0073] In another aspect of the spatial ALD process, the reactive gases are delivered simultaneously to the reaction zone, but separated by an inert gas curtain and / or a vacuum curtain. The gas curtain can be a combination of an inert gas flow into the processing chamber and a vacuum vapor flow out of the processing chamber. The substrate moves relative to the gas delivery apparatus so that any given point on the substrate is exposed to only one reactive gas.

[0074] As used herein, "pulse" or "supply" refers to the amount of source gas that is intermittently or discontinuously introduced into a process chamber. Depending on the duration of the pulse, the amount of a particular compound in each pulse may vary over time. A particular process gas may include a single compound or a mixture / combination of two or more compounds.

[0075] In a time-domain ALD process, in some embodiments, exposure to each reactive gas (including but not limited to the metal and dielectric materials to be used for the ALD film) is separated by a time delay to allow each precursor to adhere and / or react on the substrate surface and then be purged from the processing chamber. Mixing of reactive gases is prevented by purging the processing chamber between subsequent exposures.

[0076] In another aspect of the time-domain ALD process of some embodiments, a time delay exists between pulses of the reactive gas. During each time delay, a purge gas, such as argon, is introduced into the processing chamber to purge the reaction zone or otherwise remove any residual reactive gas or reaction products or byproducts from the reaction zone. Alternatively, the purge gas may flow continuously throughout the deposition process, such that only the purge gas flows during the time delay between pulses of the reactive gas. The reactive gas is alternatively pulsed multiple times with pulses of the purge gas in between. Purging may also be accomplished using a vacuum pump with or without an inert gas.

[0077] The duration for each pulse / feed is variable and can be adjusted to accommodate, for example, the volumetric capacity of the process chamber and the capacity of the vacuum system coupled to the process chamber. In addition, the feed time of the reactive gas can vary depending on the flow rate of the reactive gas, the temperature of the process gas, the type of control valve, the type of process chamber employed, and the ability of the components of the process gas to adsorb onto the substrate. The feed time can also vary based on the type of layer being formed and the geometry of the device being formed. The feed time should be long enough to provide a volume of compound sufficient to adsorb / chemisorb onto substantially the entire surface of the substrate and form a layer of the process gas component thereon.

[0078] Once the carbon-containing film is deposited, the method may optionally include further processing (eg, bulk deposition of a dielectric film). In some embodiments, the further processing may be an ALD process.

[0079] The present disclosure provides that the process can be stored as a software routine in a memory, which, when executed by a processor, causes the processing chamber to perform the process of the present disclosure. The software routine can also be stored and / or executed by a second processor (not shown), which is located remotely from the hardware controlled by the processor. Some or all of the methods of the present disclosure can also be executed in hardware. Therefore, the process can be implemented in software and executed in hardware using a computer system, as, for example, a special application integrated circuit or other type of hardware implementation, or as a combination of software and hardware. When executed by a processor or controller, the software routine converts a general-purpose computer into a special-purpose computer (controller), which controls the operation of the chamber so that the process can be performed. The process may be stored on a non-transitory computer-readable medium comprising instructions that, when executed by a controller of a substrate processing chamber, cause the substrate processing chamber to perform operations comprising: flowing a first precursor over a substrate comprising a patterned surface to form a first portion of a carbon-containing film on the patterned surface, the first precursor comprising a first reactive group, and the patterned surface comprising a sidewall and a top surface; removing a first precursor effluent comprising the first precursor from the substrate; flowing a second precursor comprising a second reactive group over the substrate to react with the first reactive group to form a carbon-containing film on the patterned surface; removing a second precursor effluent comprising the second precursor from the substrate; and etching the substrate to remove a portion of the carbon-containing film from a top surface of the patterned surface to form a spacer on a first sidewall and a second sidewall of the patterned surface.

[0080] References throughout this specification to "one embodiment," "certain embodiments," "one or more embodiments," or "an embodiment" mean that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearance of phrases such as "in one or more embodiments," "certain embodiments," "in an embodiment," or "in an embodiment" in various places throughout this specification do not necessarily refer to the same embodiment of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0081] Although the disclosure herein has been described with reference to specific embodiments, it will be understood that these embodiments are merely illustrative of the principles and applications of the disclosure. It will be apparent to those skilled in the art that various modifications and variations may be made to the methods and apparatus of the disclosure without departing from the spirit and scope of the disclosure. Therefore, the disclosure is intended to include modifications and variations within the scope of the appended claims and their equivalents.

Claims

1. A method for depositing a carbon-containing film, the method comprising the following steps: flowing a first precursor over an EUV photoresist comprising a patterned surface to form a first portion of a carbon-containing film on the patterned surface, the first precursor comprising a first reactive group; removing a first precursor effluent including the first precursor from the EUV photoresist; flowing a second precursor comprising a second reactive group over the EUV photoresist to react with the first reactive group to conformally form the carbon-containing film on the patterned surface; as well as A second precursor effluent including the second precursor is removed from the EUV photoresist.

2. The method of claim 1, wherein the first precursor has the general formula R 1 -(X) n Where R 1 Contains one or more of the following: alkyl, alkenyl, aryl, aromatic group, and cycloalkyl, X n Contains one or more of the following: a hydroxyl group, an aldehyde group, a ketone group, an acid group, an amine group, an isocyanate group, a thiocyanate group, and an acyl chloride group, and n is an integer ranging from 1 to 6.

3. The method of claim 1, wherein the second precursor has the general formula R 2 -(Y) n Where R 2 Contains one or more of the following: an alkyl group, an alkenyl group, an aryl group, an aromatic group, and a cycloalkyl group, Y n Contains one or more of the following: a hydroxyl group, an aldehyde group, a ketone group, an acid group, an amine group, an isocyanate group, a thiocyanate group, and an acyl chloride group, and n is an integer ranging from 1 to 6.

4. The method of claim 1, wherein the first precursor and the second precursor are independently selected from one or more of the following: terephthalaldehyde, phenylenediamine, ethylenediamine, hexamethylenediamine, terephthaloyl chloride, 1,3,5-benzene trimellitic acid trichloride, pyromellitic dianhydride, benzene-1,3,5-tricarbaldehyde, 1,4-phenylene diisocyanate, 4,4'-oxydianiline, and tris(2-aminoethyl)amine.

5. The method of claim 4, wherein the first precursor comprises terephthalaldehyde and the second precursor comprises phenylenediamine.

6. The method of claim 1, further comprising the steps of: The patterned surface is etched to remove a portion of the carbon-containing film from a top surface of the patterned surface.

7. The method of claim 1, further comprising the steps of: The method is repeated to form the carbon-containing film having a thickness in a range from 0.1 nm to 50 nm. 8 . The method of claim 7 , wherein the carbon-containing film has a thickness in a range from 1 nm to 5 nm.

9. The method of claim 1, wherein the step of removing the first precursor comprises the steps of: flowing a purge gas over the EUV photoresist; as well as The mixture of the first precursor effluent and the purge gas is removed from the EUV photoresist.

10. The method of claim 1, wherein the patterned surface is an EUV photoresist pattern. The method of claim 10 , wherein the patterned surface comprises a mandrel.

12. A method for depositing a carbon-containing film, the method comprising the following steps: Flowing a first precursor over an EUV photoresist comprising a patterned surface, the first precursor having a general formula R 1 -(X) n Where R 1 Contains one or more of the following: alkyl, alkenyl, aryl, aromatic group, and cycloalkyl, X n comprises one or more of the following: a hydroxyl group, an aldehyde group, a ketone group, an acid group, an amine group, an isocyanate group, a thiocyanate group, and an acyl chloride group, and n is an integer in the range from 1 to 6, wherein the first precursor reacts with reactive groups on the patterned surface to form a first portion of a carbon-containing film; removing a first precursor effluent including the first precursor from the EUV photoresist; A second precursor is flowed over the EUV photoresist, wherein the second precursor has a general formula R 2 -(Y) n Where R 2 Contains one or more of the following: an alkyl group, an alkenyl group, an aryl group, an aromatic group, and a cycloalkyl group, Y n comprises one or more of the following: a hydroxyl group, an aldehyde group, a ketone group, an acid group, an amine group, an isocyanate group, a thiocyanate group, and an acyl chloride group, and n is an integer in the range from 1 to 6, wherein the second precursor reacts with the first portion to form a conformal carbon-containing film; removing a second precursor effluent including the second precursor from the EUV photoresist; and The EUV photoresist is etched to remove a portion of the carbon-containing film from a top surface of the patterned surface.

13. The method of claim 12, wherein the first precursor and the second precursor are independently selected from one or more of the following: terephthalaldehyde, phenylenediamine, ethylenediamine, hexamethylenediamine, terephthaloyl chloride, 1,3,5-benzene trimellitic acid trichloride, pyromellitic dianhydride, benzene-1,3,5-tricarbaldehyde, 1,4-phenylene diisocyanate, 4,4'-oxydianiline, and tris(2-aminoethyl)amine.

14. The method of claim 13, wherein the first precursor comprises terephthalaldehyde and the second precursor comprises phenylenediamine.

15. The method of claim 12, wherein the step of removing the first precursor comprises the steps of: flowing a purge gas over the EUV photoresist; as well as The mixture of the first precursor effluent and the purge gas is removed from the EUV photoresist.

16. The method of claim 12, wherein the patterned surface is an EUV photoresist pattern, and the carbon-containing film is formed on a sidewall and reduces line edge roughness (LER).

17. The method of claim 12, wherein the patterned surface comprises a mandrel.

18. The method of claim 12, further comprising the steps of: The method is repeated to form the carbon-containing film having a thickness in a range from 0.1 nm to 50 nm.

19. The method of claim 18, wherein the carbon-containing film has a thickness in a range from 1 nm to 5 nm.

20. A method for reducing line edge roughness (LER) of EUV photoresist, the method comprising the following steps: Molecular layer deposition of a carbon-containing film on the patterned surface of the EUV photoresist, wherein the step of molecular layer deposition comprises the following steps: flowing a first precursor over the EUV photoresist comprising the patterned surface to form a first portion of the carbon-containing film on the patterned surface, the first precursor comprising a first reactive group; removing a first precursor effluent including the first precursor from the EUV photoresist; flowing a second precursor comprising a second reactive group over the EUV photoresist to react with the first reactive group to conformally form the carbon-containing film on the patterned surface; and removing a second precursor effluent including the second precursor from the EUV photoresist, The carbon-containing film is formed on the sidewall of the EUV photoresist and reduces line edge roughness (LER).

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