Method for reducing line edge roughness of EUV photoresist pattern

Abstract

A method is described for depositing a conformal carbon-containing film on an EUV photoresist to reduce line edge roughness (LER). Exemplary processing methods can include flowing a first precursor over a patterned EUV surface to form a first portion of an initial carbon-containing film on the structure. The method can include removing the first precursor effluent from the patterned EUV photoresist. Then, a second precursor can be flowed over the patterned EUV photoresist to react with the first portion of the initial carbon-containing film. The method can include removing the second precursor effluent from the patterned EUV photoresist. The method can include etching the substrate to remove a portion of the carbon-containing film, exposing the upper surface of the patterned surface, and exposing the substrate between the patterned surfaces.

Description

Technical Field

[0001]

[0001] Embodiments of the present disclosure relate to a method for depositing a carbon-based film on a nanostructure. Specifically, embodiments of the present disclosure are directed to a method for depositing a carbon-based film to improve the line edge roughness (LER) and / or line width roughness (LWR) of a patterned EUV photoresist.

Background Art

[0002]

[0002] Photolithography transfers a negative or positive image onto a substrate (e.g., a semiconductor wafer) using a photoresist, which is a photosensitive film. After coating the substrate with the photoresist, the coated substrate is exposed to an actinic radiation source, thereby causing a chemical transformation in the exposed regions of the surface. Depending on the type of photoresist used, the substrate coated with the photoresist is then treated with a developer to dissolve or otherwise remove either the exposed or unexposed regions of the coated substrate.

[0003]

[0003] However, lithography techniques for creating features smaller than 30 nanometers suffer from many drawbacks. For example, the line width variations of the resist films produced by such techniques can become unacceptably large from the perspective of tightening the dimensional tolerances typically required in this range (e.g., tolerances on the order of the scale of the molecular components of the resist film). Such line width variations can be classified as line edge roughness (LER) and / or line width roughness (LWR).

[0004]

[0004] Line edge roughness and line width roughness represent line width variations that can lead to device property variations. As the critical dimensions of integrated circuits continue to shrink, line width variations will play an increasingly important role in the error budget of lithography's critical dimensions (CD). Some suspected causes of LER and LWR in resist patterns include reticle features, aerial image features, and resist material properties.

[0005]

[0005] Extreme ultraviolet (EUV) lithography (EUVL) is promising as a next-generation lithography technique. Current important issues in EUV technology include the roughness of photoresist. Currently, plasma post-treatment is used to smooth the surface of the photoresist, but this plasma post-treatment may damage the photoresist pattern or reduce the height of the photoresist.

[0006]

[0006] Therefore, there is currently a need in the art for alternative methods to reduce the line edge roughness of EUV photoresist patterns.

Summary of the Invention

[0007]

[0007] One or more embodiments of the present disclosure are directed to a method of depositing a carbon-containing film. The method includes flowing a first precursor over an EUV photoresist including a 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 the carbon-containing film on the patterned surface; and removing a second precursor effluent including the second precursor from the EUV photoresist.

[0008]

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

[0009]

[0009] A further embodiment of the present disclosure is directed to a method for reducing 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 an EUV photoresist, the molecular layer deposition comprising 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 the 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 the carbon-containing film on the patterned surface; and removing the second precursor effluent comprising the second precursor from the EUV photoresist, wherein the carbon-containing film is formed on the sidewalls of the EUV photoresist to reduce line edge roughness (LER).

[0010]

[0010] To better understand the above-described features of the present disclosure, a more specific description of the present disclosure briefly summarized above can be obtained by referring to the embodiments. Some of these embodiments are illustrated in the accompanying drawings. It should be noted, however, that the present disclosure may admit other equally effective embodiments, so the accompanying drawings illustrate only typical embodiments of this disclosure and should not be regarded as limiting the scope of the present disclosure. The embodiments described in this document are shown by way of example and not limitation in the figures of the accompanying drawings, and like reference numerals indicate like elements.

Brief Description of the Drawings

[0011]

Figure 1A

[0011] A cross-sectional view of a substrate according to one or more embodiments is shown.

Figure 1B

[0012] A cross-sectional view of a substrate according to one or more embodiments is shown.

Figure 1C

[0013] A cross-sectional view of a substrate according to one or more embodiments is shown.

Figure 1D

[0014] A cross-sectional view of a substrate according to one or more embodiments is shown.

Figure 2

[0015] A process flow diagram of a method for depositing a film on a substrate according to one or more embodiments is shown. **DETAILED DESCRIPTION OF THE INVENTION**

[0012]

[0016] Before describing some exemplary embodiments of the present invention, it should be understood that the present invention is not limited to the details of the structures or processing 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.

[0013]

[0017] As used herein, the term "about" means "approximately" or "substantially" and means a variation of up to ±15% of the specified numerical value or range in light of the specified numerical value or range. For example, values that differ by ±14%, ±10%, ±5%, ±2%, or ±1% satisfy the definition of about.

[0014]

[0018] As used in this specification and the appended claims, the term "substrate" or "wafer" refers to the surface or portion of the surface on which processing acts. It will also be understood by those skilled in the art that, unless the context clearly dictates otherwise, a reference to a substrate may refer only to a portion of the substrate. Further, a reference to deposition on a substrate can mean both a bare substrate and a substrate having one or more films or features deposited or formed thereon.

[0015]

[0019] As used herein, the "substrate" or "substrate surface" refers to a portion of the substrate or a portion of the surface of a material formed on the substrate on which film treatment is performed. For example, the substrate surface on which treatment can be performed may be, depending on the application, materials such as silicon, silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials. The substrate includes, but is not limited to, semiconductor wafers. The substrate can 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 directly performing film treatment on the surface of the substrate itself, in the present disclosure, any of the disclosed film treatment steps may be performed on a lower layer formed on the substrate, as will be disclosed in more detail below, and the term "substrate surface" is intended to include this lower layer as the context indicates. Thus, for example, when a film / layer or a partial film / layer is deposited on the substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate. The substrate can have various dimensions, such as wafers with a diameter of 200 mm or 300 mm, as well as rectangular or square panels, etc. In some embodiments, the substrate includes a separate rigid material.

[0016]

[0020] The term "on" indicates direct contact between elements. The term "direct" indicates direct contact between elements without intervening elements.

[0017]

[0021] As used herein, terms such as "extreme ultraviolet", "EUV", etc. refer to radiation in the range of about 10 nm to 124 nm. In some embodiments, it refers to EUV radiation in the range of 10 nm to 15 nm. In one or more embodiments, EUV light having a wavelength of about 13.5 nm is used. (Also referred to as EUV light)

[0018]

[0022] Terms such as "precursor", "reactant", "reactive gas", etc. used in this book and the appended claims are used interchangeably to refer to any gas species that can react with the substrate surface.

[0019]

[0023] The terms "reactive compound", "reactive gas", "reactive species", "precursor", "process gas", etc., as used in this specification and the appended claims, are used interchangeably to mean a substance having 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 a part of the substrate is continuously exposed to two or more reactive compounds introduced into the reaction zone of the processing chamber.

[0020]

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

[0021]

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

[0022]

[0026] Embodiments of the present technology include a molecular layer deposition (MLD) method and system for forming a carbon-containing material on a patterned photoresist. An exemplary MLD method may include providing a first deposition precursor on the surface of a patterned EUV photoresist, the precursor forming a first layer (e.g., a first monolayer) on the surface of the mandrel. During or after the formation of the first layer, unbound deposition effluent, which may contain unbound molecules of the first deposition precursor, is removed from the processing region where the patterned EUV photoresist is exposed. Thereafter, a second deposition precursor may be introduced into the patterned EUV photoresist. In the EUV photoresist, 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 the formation of the second layer, unbound deposition effluent, which may contain unbound molecules of the second deposition precursor, is removed from the processing region. The patterned EUV photoresist now has a carbon-containing material layer bonded to the patterned mandrel surface of the EUV photoresist. Additional compound layers of the first and second layers may be built on top of the deposited layers until the number of compound layers reaches the desired thickness of the carbon-containing material on the patterned surface of the EUV photoresist. Thereafter, the compound layer is annealed or plasma treated to form a carbon-containing material on the surface of the EUV photoresist.

[0023]

[0027] One or more embodiments advantageously provide a solution to problems in conventional methods of forming a carbon-containing material on an EUV photoresist. For example, the present technology forms a carbon-containing material with significantly fewer voids, fractures, and other physical defects than carbon-containing materials formed using methods of spin-on-carbon (SOC) and flowable chemical-vapor-deposition (FCVD). The present technology can also form a carbon-containing material that is denser and less porous than materials formed by SOC and FCVD. The high hydrogen levels found in many SOC and FCVD precursors cause high shrinkage rates when the as-deposited material is processed to form the final material. High shrinkage rates of up to 50 volume % are not uncommon in processed as-deposited SOC and FCVD materials, creating gaps, fractures, and voids in the processed material and stressing substrate features in contact with the material. The technology of the present invention produces a carbon-containing material in which the as-deposited material has a shrinkage rate of 10 volume % or less (e.g., a shrinkage rate of about 5 volume % or less, a shrinkage rate of 5-10 volume %).

[0024]

[0028] One or more embodiments advantageously provide a solution to problems in conventional plasma deposition methods of forming a carbon-containing material on an EUV photoresist. Conventional plasma deposition methods, such as plasma-enhanced chemical-vapor-deposition (PECVD) and high-density-plasma chemical-vapor-deposition (HDPCVD), often generate ion sputtering that can damage substrate features on the EUV photoresist and can also generate re-sputtered ions and other species that can cause defects within the deposited carbon-containing material. Additionally, conventional plasma deposition methods often volumetrically deposit material non-uniformly inside and around substrate features, generate voids inside and around substrate trenches and steps, and generate non-uniform surfaces on flat substrate regions. The present technology can form a carbon-containing material that does not require a plasma that can damage substrate features during deposition, has a high level of conformality with narrow substrate features (e.g., a dimension width of about 25 nm or less), and has a high aspect ratio (e.g., an aspect ratio of 10:1 or greater).

[0025]

[0029] Embodiments of the present disclosure are illustrated by figures showing processes for forming devices (e.g., transistors) and semiconductor structures according to one or more embodiments of the present disclosure. The illustrated processes are merely illustrative of possible uses of the disclosed processes, and one of ordinary skill in the art will recognize that the disclosed processes are not limited to the illustrated uses.

[0026]

[0030] Figures 1A - 1D show cross - sectional views of EUV photoresist processed by the method of one or more embodiments. Figure 2 shows a process flow diagram of method 200 for depositing a carbon - containing film according to one or more embodiments. Referring to Figures 1A - 1D and Figure 2, in one or more embodiments, a patterned EUV photoresist is provided in step 202. As used in this specification and the appended claims, the term "provided" means that the substrate is made available for processing (e.g., placed in a processing chamber). Figure 1A is a cross - sectional view 100 of EUV photoresist processed by the method of Figure 2. Figure 1B is a top view 105 of the EUV photoresist.

[0027]

[0031] Referring to Figures 1A and 1B, in 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 trench, a via, a hole, etc. In a particular 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 by exposing a portion using EUV radiation and a developer and leaving a residue of the photoresist. As used in this specification, "photoresist" refers to all photosensitive materials used in processes (such as photolithography and photogravure) for forming a patterned coating on a surface. The patterned surface 104 and the mandrel patterned with the photoresist can be formed by one or more of EUV lithography or deep ultraviolet (DUV) electron beam lithography.

[0028]

[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 shown in FIG. 1B, the patterned surface 104 includes a plurality of surface irregularities 199, whereby the patterned surface 104 is rough and not smooth. In one or more embodiments, the patterned surface 104 (which may also be referred to as a photoresist mandrel) may have pattern variations along the line edges (surface irregularities 199), and these pattern variations cause line width roughness (LWR) and line edge roughness (LER) that can result in variations in each layer during pattern transfer. Without being bound by theory, in one or more embodiments, a thin molecular layer deposition (MLD) carbon-based film 106 is coated over the photoresist pattern of the patterned surface 104 to smooth the photoresist mandrel surface and reduce LWR and LER.

[0029]

[0033] Although not shown in FIGS. 1A and 1C for ease of drawing, those skilled in the art will recognize that surface irregularities 199 are present on the patterned surface 104.

[0030]

[0034] As will be recognized by those skilled in the art, a plurality of patterned surfaces 104, mandrels may be present on the EUV photoresist 102. In some embodiments, there are at least two patterned surfaces 104 that are separate from the feature 101.

[0031]

[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 can be formed internally. The feature 101 can be characterized by any shape or configuration according to the present technology. In some embodiments, the feature 101 can be or include a trench structure, via structure, or aperture formed in the substrate. The feature 101 can be characterized by any shape or size, but in some embodiments, the substrate feature 101 can be characterized by a higher aspect ratio, or the ratio of the depth to the width of the feature across the feature 101. For example, in some embodiments, the substrate feature can be characterized by an aspect ratio of 5:1 or more, 10:1 or more, 15:1 or more, 20:1 or more, 25:1 or more, 30:1 or more, 40:1 or more, 50:1 or more, or a higher aspect ratio. Additionally, the feature 101 can be characterized by a narrow width or diameter, including between two sidewalls, across the entire feature, such as a critical dimension in the range of 5 nm to 500 nm, 10 nm to 200 nm, or 20 nm to 100 nm.

[0032]

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

[0033]

[0037] FIG. 1C is a cross-sectional view 100 of an EUV photoresist processed by the method of FIG. 2. FIG. 1D is a top view 105 of the EUV photoresist. Referring to FIGS. 1C, 1D, and 2, in one or more embodiments, in step 204, the EUV photoresist 102 and the patterned surface 104 are optionally exposed to a pretreatment process for polishing, coating, doping, etching, reducing, oxidizing, hydroxylation, annealing, UV curing, electron beam curing, and / or baking the substrate.

[0034]

[0038] In one or more embodiments, the carbon-containing film 106 is formed very conformally over the EUV photoresist 102 and the patterned surface 104. As used herein, a "very conformal" layer refers to a layer that is substantially the same thickness throughout (e.g., at the top, middle, and bottom of sidewalls, and at the bottom of feature 101). A very conformal layer has a thickness difference of about 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or 0.5% or less.

[0035]

[0039] Referring to FIG. 2, in step 206, a first type of precursor is introduced / flowed into the substrate processing region of the processing chamber and onto the substrate surface. The first precursor strongly binds to the EUV photoresist 102 and the patterned surface 104.

[0036]

[0040] In one or more embodiments, the first precursor may be a carbon-containing precursor having at least two reactive groups capable of forming a bond with a group linked 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 such that a bond connecting the first precursor molecules to the EUV photoresist 102 and the patterned surface 104 can be formed. The reaction between the first precursor molecules and the groups in the EUV photoresist 102 and the patterned surface 104 continues until most or all of the surface groups are bonded to the reactive groups in the first precursor molecules. A first portion 106 of the carbon-containing film is formed that inhibits further reaction between the first precursor molecules in the first precursor effluent and the substrate.

[0037]

[0041] The first precursor can include any suitable precursor known to those skilled in the art. In one or more embodiments, the first precursor may have the general formula R 1 -(X) n where n is an integer in the range of 1 to 6, and R 1 includes one or more of an alkyl group, an alkenyl group, an aryl or aromatic group, and a cycloalkyl group. Xn contains one or more of a hydroxy group, an aldehyde group, a ketone group, an acidic group, an amino group, an isocyanate group, a thiocyanate group, and an acyl chloride group.

[0038]

[0042] Unless otherwise specified, the terms "lower alkyl", "alkyl", or "alk" as used herein, either alone or as part of another group, generally refer to a hydrocarbon having 1 to 20 carbon atoms, or 1 to 10 carbon atoms, in a normal chain, including both linear and branched hydrocarbons such as, for example, methyl, ethyl, propyl, isopropyl, butyl, t-butyl, isobutyl, pentyl, hexyl, isohexyl, heptyl, 4,4-dimethylpentyl, octyl, 2,2,4-trimethylpentyl, nonyl, decyl, undecyl, dodecyl, and various branched isomers thereof. Such groups may optionally contain up to 1 to 4 substituents. Alkyl may or may not be substituted.

[0039]

[0043] Such groups may optionally contain up to 1 to 4 substituents such as, in some cases, halo, for example, F, Br, Cl, or I, or CF3, alkyl, alkoxy, aryl, aryloxy, aryl(aryl) or diaryl, arylalkyl, arylalkyloxy, alkenyl, cycloalkyl, cycloalkylalkyl, cycloalkylalkyloxy, amino, hydroxy, hydroxyalkyl, acyl, heteroaryl, heteroaryloxy, heteroarylalkyl, heteroarylalkoxy, aryloxyalkyl, alkylthio, arylalkylthio, aryloxyaryl, alkylamide, alkanoylamino, arylcarbonylamino, nitro, cyano, thiol, haloalkyl, trihaloalkyl, and / or alkylthio, etc. In one or more embodiments, R 1 is independently selected from C1-C 20 alkyl. In other embodiments, R 1 is derived from C1-C 12 alkyl.

[0040]

[0044] As used herein, the terms "alkene", "alkenyl", or "lower alkenyl" mean a vinyl, 2-propenyl, 3-butenyl, 2-butenyl, 4-pentenyl, 3-pentenyl, 2-hexenyl, 3-hexenyl, 2-heptenyl, 3-heptenyl, 4-heptenyl, 3-octenyl, 3-nonenyl, 4-decenyl, 3-undecenyl, 4-dodecenyl, 4,8,12-tetradecatrienyl, etc., a straight-chain or branched-chain radical having 2 to 20 carbons, or 2 to 12 carbons, and having 1 to 8 carbons in the straight chain, and containing 1 to 6 double bonds in the straight chain, and these may be optionally substituted with 1 to 4 substituents, namely, halogen, haloalkyl, alkyl, alkoxy, alkenyl, alkynyl, aryl, arylalkyl, cycloalkyl, amino, hydroxy, heteroaryl, cycloheteroalkyl, alkanoylamino, alkylamide, arylcarbonyl-amino, nitro, cyano, thiol, alkylthio, and / or any of the alkyl substituents described herein.

[0041]

[0045] As used herein, the term "alkynyl" or "lower alkynyl" means a straight-chain or branched-chain radical having 2 to 20 carbon atoms, or 2 to 12 carbon atoms, or 2 to 8 carbon atoms 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-decynyl, 3-undecynyl, 4-dodecynyl, etc., which contains one triple bond in the straight chain, and these may be optionally substituted with 1 to 4 substituents, namely, halogen, haloalkyl, alkyl, alkoxy, alkenyl, alkynyl, aryl, arylalkyl, cycloalkyl, amino, heteroaryl, cycloheteroalkyl, hydroxy, alkanoylamino, alkylamide, arylcarbonylamino, nitro, cyano, thiol, and / or alkylthio, and / or any of the alkyl substituents described herein.

[0042]

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

[0043]

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

[0044]

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

[0045]

[0049] In one or more embodiments, the formation ratio 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. The substrate temperature during an exemplary formation process may be 50 °C or higher, 60 °C or higher, 70 °C or higher, 80 °C or higher, 90 °C or higher, 100 °C or higher, 110 °C or higher, 120 °C or higher, 130 °C or higher, 140 °C or higher, 150 °C or higher, or higher. By maintaining an elevated substrate temperature (e.g., about 100 °C or higher in some embodiments), increased nucleation sites may be available along the EUV photoresist 102 and the patterned surface 104, improving formation by improving coverage at each location and reducing void formation. In one or more embodiments, the temperature ranges from 60 °C to 150 °C, or from 25 °C to 300 °C.

[0046]

[0050] The first precursor effluent may remain in the substrate processing region for a time sufficient to form most or all of the first portion of the carbon-containing film 106. The precursors may be provided in alternating pulses to grow the material. In some embodiments, the pulse time of one or both of the first precursor and the second precursor may be 0.1 seconds or longer, 1 second or longer, 2 seconds or longer, 3 seconds or longer, 4 seconds or longer, 5 seconds or longer, 10 seconds or longer, 20 seconds or longer, 40 seconds or longer, 60 seconds or longer, 80 seconds or longer, 100 seconds or longer, or longer.

[0047]

[0051] Referring to FIG. 2, in step 208, after the first portion 110 of the carbon-containing film 106 is formed, the first precursor is purged from or removed from the substrate processing region. The effluent of the first precursor can be removed by pumping from the substrate deposition region over a time range of about 10 seconds to about 100 seconds. Additional exemplary time ranges can include, among other exemplary time ranges, about 20 seconds to about 50 seconds, and 25 seconds to about 45 seconds. However, in some embodiments, as the purge time increases and the reactive sites begin to be removed, uniform formation may decrease. Thus, in some embodiments, the purge may be performed over a time of 60 seconds or less, 50 seconds or less, 40 seconds or less, 30 seconds or less, or even less time. In some embodiments, a purge gas can be introduced into the substrate processing region to assist in removing the effluent. Exemplary purge gases include, among other purge gases, argon (Ar), helium (He), and nitrogen (N2).

[0048]

[0052] Referring to FIG. 2, in step 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 can advantageously have a functional group that thickens the carbon-containing film 106 at one end.

[0049]

[0053] In one or more embodiments, the second precursor can be a carbon-containing precursor having at least two reactive groups that can form bonds with unreacted reactive groups of the first precursor that formed the 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 of the second precursor molecules to the first precursor molecules. The reaction between the second precursor molecules and the 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 deposition precursor is formed that inhibits further reaction between the second precursor molecules in the second precursor effluent and the first portion of the carbon-containing film 106.

[0050]

[0054] The second precursor may include any suitable precursor known to those skilled in the art. In one or more embodiments, the second precursor has the general formula R 2 -(Y) n where n is an integer in the range of 1 to 6, and R 2 includes one or more of an alkyl group, an alkenyl group, an aryl or aromatic group, and a cycloalkyl group. In one or more embodiments, R 2 is independently selected from C1-C 20 alkyl. In other embodiments, R 2 is derived from C1-C 12 alkyl. Y n includes one or more of a hydroxy group, an aldehyde group, a ketone group, an acidic group, an amino group, an isocyanate group, a thiocyanate group, and an acyl chloride group.

[0051]

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

[0052]

[0056] Specific examples of the second precursor include, but are not limited to, one or more of terephthalaldehyde, phenylenediamine, ethylenediamine, hexamethylenediamine, terephthaloyl chloride, 1,3,5-benzenetricarbonyl trichloride, pyromellitic anhydride, benzene-1,3,5-tricarboxyaldehyde, 1,4-phenylene diisocyanate, 4,4'-oxydianiline, tris(2-aminoethyl)amine, etc.

[0053]

[0057] Referring to FIG. 2, in one or more embodiments, method 200 also includes step 212 for purging or removing the second precursor effluent from the substrate processing region after the second portion of carbon-containing film 106 is formed. The effluent can be removed by pumping from the substrate deposition region over a time range of about 10 seconds to about 100 seconds. Additional exemplary time ranges can include, among other exemplary time ranges, about 20 seconds to about 50 seconds, and 25 seconds to about 45 seconds. In some embodiments, a purge gas can be introduced into the substrate processing region to assist in removing the effluent. Exemplary purge gases include, among other purge gases, argon, helium, and nitrogen.

[0054]

[0058] In one or more embodiments, the formation rate of the second portion of carbon-containing film 106 can also depend on the pressure of the second precursor effluent within the substrate processing region. An exemplary effluent pressure within the substrate processing region can be in the range of about 1 mTorr to about 20 Torr. Additional exemplary ranges include, among other exemplary ranges, 5 Torr to 15 Torr, and 9 Torr to 12 Torr.

[0055]

[0059] Referring to FIG. 2, in one or more embodiments of method 200, after one or more cycles of forming carbon-containing film 106 (e.g., after forming the first and second portions of the compound layer), there is a measurement / determination point 214 as to whether the target thickness of carbon-containing film 106 remaining deposited on EUV photoresist 102 and patterned surface 104 has been achieved. If the target thickness of carbon-containing film 106 remaining deposited has not been achieved, another cycle of forming the first and second portions of carbon-containing film 106 is performed. If the target thickness of carbon-containing film 106 remaining deposited has been achieved, another cycle for forming another carbon-containing film 106 is not initiated. Exemplary cycle numbers for forming the carbon-containing film can include from 1 to 2000. Additional exemplary ranges for the cycle number can include, among other exemplary ranges, 50 to 1000, and 100 to 750.

[0056]

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

[0057]

[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 ranges from 0.1 nm to 50 nm, or from 0.1 nm to 200 nm, or from 1 nm to 20 nm, or from 1 nm to 10 nm, or from 3 nm to 10 nm, or from 1 nm to 5 nm.

[0058]

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

[0059]

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

[0060]

[0064] In the embodiment shown by method 200 of FIG. 2, the carbon-containing film 106 as-deposited on the EUV photoresist 102 and the patterned surface 104 can be optionally post-treated in step 216. Any post-treatment step 216 can be, for example, a treatment to modify film properties (e.g., annealing or plasma treatment), or a further film deposition treatment to grow an additional film (e.g., additional ALD or CVD treatment). In some embodiments, any post-treatment step 216 can be a treatment to modify the properties of the deposited film. In some embodiments, any post-treatment step 216 can include 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 an inert gas (e.g., molecular nitrogen (N2), argon (Ar)), a reducing gas (e.g., molecular hydrogen (H2), or ammonia (NH3)), or an oxidizing agent (e.g., but not limited to, oxygen (O2), ozone (O3), or peroxide). The annealing can be performed over any suitable length of time. In some embodiments, the carbon-containing film is annealed over 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, by annealing the as-deposited carbon-containing film, the density of the film increases, the resistivity of the film decreases, and / or the purity of the film increases.

[0061]

[0065] In another embodiment, in step 216, the carbon-containing film 106 is subjected to an etching process to remove a portion of the carbon-containing film 106, expose the upper surface 110 of the patterned surface 104, and expose a portion of the EUV photoresist 102 between the carbon-containing film 106 and the patterned surface 104. The etching process can 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.

[0062]

[0066] Some embodiments of the present disclosure are directed to electronic devices comprising nanostructures having a carbon-containing film 106 as a layer remaining after an etching process removes the carbon-containing film 106 from the bottom of trenches between structures. The carbon-containing film 106 may act as an etching protection layer or an etching resistance layer for the sidewalls of the nanostructures. In some embodiments, the carbon-containing film 106 acts as a liner material when etching is not performed. In some embodiments, the carbon-containing film 106 acts as a spacer when formed on the sidewalls of an EUV photoresist pattern to reduce line edge roughness (LER) and line width roughness (LWR).

[0063]

[0067] In some embodiments, the processing area is within a modular system with multiple chambers that perform various functions including substrate center detection 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 may house a robot capable of reciprocally transporting substrates between the processing chamber and the load lock chamber. The transfer chamber is typically maintained in a vacuum state and provides an intermediate stage for reciprocally transporting substrates from one chamber to another and / or to the load lock chamber located at the front end of the cluster tool. However, the actual chamber configuration and combination can be changed for the purpose of implementing the specific steps of the processes described herein. Other processing chambers that can be used include, but are not limited to, cyclical layer deposition (CLD), atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etching, pre-cleaning, chemical cleaning, heat treatments such as RTP, plasma nitridation, degassing, orientation, hydroxylation, and other substrate processing. By performing processing in the processing chambers of the modular system, surface contamination of the substrate by atmospheric impurities can be avoided without oxidation occurring prior to the deposition of subsequent films.

[0064]

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

[0065]

[0069] The substrate can be processed in a single substrate deposition chamber where a single substrate is loaded, processed, and unloaded before another substrate is processed. The substrate can also be processed in a continuous manner similar to a conveyor system where multiple substrates are individually loaded into the first portion of the chamber, move through the chamber, and are unloaded from the second portion of the chamber. The shape of the chamber and the associated conveyor system can form a linear or curved path. Further, the processing chamber may be a carousel in which multiple substrates move around a central axis and are exposed to processes such as deposition, etching, annealing, cleaning, etc. over the entire carousel path.

[0066]

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

[0067]

[0071] The substrate may also be in a stationary state or rotated during processing. The rotating substrate can be rotated continuously or in non - continuous steps (about the substrate axis). For example, the substrate may be rotated throughout the process, or rotated incrementally during exposure to different reactive gases or purge gases. Rotating the substrate (continuously or step - wise) during processing can help minimize the effects of local variations in the gas flow pattern and produce more uniform deposition or etching.

[0068]

[0072] In spatial ALD processing, reactive gases are flowed to various processing regions within the processing chamber. The various processing regions are separated from adjacent processing regions so that the reactive gases do not mix. The substrate can be moved between the processing regions to individually expose the substrate to the reactive gases. During movement of the substrate, no point on the substrate is substantially simultaneously exposed to multiple reactive gases by exposing various portions of the substrate surface or the material on the substrate surface to two or more reactive gases. As will be understood by those skilled in the art, a very small portion of the substrate may be simultaneously exposed to multiple reactive gases by diffusion of the gas within the processing chamber, and such simultaneous exposure may not be intended.

[0069]

[0073] In another aspect of spatial ALD processing, the reactive gases are supplied to the reaction zone simultaneously but are separated by an inert gas curtain and / or a vacuum curtain. This gas curtain can be a combination of an inert gas flow into the processing chamber and a vacuum flow out of the processing chamber. The substrate is moved relative to the gas supply device such that any given point on the substrate is exposed to only one reactive gas.

[0070]

[0074] As used herein, "pulse" or "dose" refers to the amount of source gas introduced intermittently or discontinuously into the processing chamber. The amount of a particular compound within each pulse can vary over time depending on the duration of the pulse. A particular process gas can include a single compound or a mixture / combination of two or more compounds.

[0071]

[0075] In some embodiments, in time-domain ALD processing, the exposure to each reactive gas, including but not limited to metal materials and dielectric materials used in the ALD film, is separated by a time delay such that each compound can adhere to and / or react on the substrate surface and then be purged from the processing chamber. By purging the processing chamber between subsequent exposures, mixing of the reactive gases is avoided.

[0072]

[0076] In another aspect of the time-domain ALD processing 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, reaction product, or reaction by-product from the reaction zone. Alternatively, the purge gas can 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 pulsed multiple times, alternating with pulses of the purge gas in between. The purge can also be achieved using an inert gas or using a vacuum pump without using an inert gas.

[0073]

[0077] The duration of each pulse / dose is variable and can be adjusted, for example, to adapt to the spatial capacity of the processing chamber as well as the capabilities of the vacuum system connected to the processing chamber. Further, the dose 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 processing chamber used, and the ability of the process gas components to adsorb on the substrate. Also, the dose time can vary based on the type of layer being formed and the shape dimensions of the device being formed. The dose time must be long enough to provide a sufficient amount of the compound to substantially adsorb / chemisorb across the entire surface of the substrate and form a layer of the process gas components thereon.

[0074]

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

[0075]

[0079] According to the present disclosure, the process is generally stored in memory as a software routine and, when executed by a processor, can cause the process of the present disclosure to be executed in a processing chamber. The software routine can also be stored and / or executed by a second processor (not shown) located remotely from the hardware controlled by the processor. Also, some or all of the methods of the present disclosure can be executed in hardware. Thus, the process can be implemented in software and executed in hardware using a computer system, for example, as an application specific integrated circuit or other type of hardware implementation, or as a combination of software and hardware. When the software routine is executed by a processor or a controller, it converts a general-purpose computer into a dedicated computer (controller) that controls the chamber operation so that the process is executed. The process can be stored in a non-transitory computer-readable medium containing instructions, and when these instructions are executed by a controller of a substrate processing chamber, the substrate processing chamber is caused to perform the following steps. Flowing a first precursor containing a first reactive group onto a substrate including a patterned surface to form a first portion of a carbon-containing film on the patterned surface including sidewalls and an upper surface; removing a first precursor effluent containing the first precursor from the substrate; flowing a second precursor containing a second reactive group onto the substrate to react with the first reactive group to form a carbon-containing film on the patterned surface; removing a second precursor effluent containing the second precursor from the substrate; and etching the substrate to remove a portion of the carbon-containing film from the upper surface of the patterned surface to form a spacer layer on a first sidewall and a second sidewall of the patterned surface.

[0076]

[0080] Throughout this specification, references to "one embodiment", "a particular embodiment", "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 appearances of the phrases "in one or more embodiments", "in a particular embodiment", "in one embodiment", or "in an embodiment" in various places throughout this specification are not necessarily referring 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.

[0077]

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

Claims

1. A method of depositing a carbon-containing film, comprising: Flowing a first precursor over an EUV photoresist including the patterned surface to form a first portion of the carbon-containing film on the patterned surface, wherein the first precursor contains a first reactive group; Removing a first precursor effluent containing the first precursor from the EUV photoresist; Flowing a second precursor containing 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; Removing a second precursor effluent containing the second precursor from the EUV photoresist. A method.

2. The first precursor has the general formula R １ -(X) ｎ and has R １ contains one or more of an alkyl group, an alkenyl group, an aryl group, an aromatic group, and a cycloalkyl group, and X ｎ contains one or more of a hydroxy group, an aldehyde group, a ketone group, an acidic group, an amino group, an isocyanate group, a thiocyanate group, an acid group, and an acyl chloride group, and n is an integer in the range of 1 to 6 The method according to claim 1.

3. The second precursor has the general formula R ２ -(Y) ｎ and has R ２ contains one or more of an alkyl group, an alkenyl group, an aryl group, an aromatic group, and a cycloalkyl group, and Y ｎ contains one or more of a hydroxy group, an aldehyde group, a ketone group, an acidic group, an amino group, an isocyanate group, a thiocyanate group, and an acyl chloride group, and n is an integer in the range of 1 to 6 The method according to claim 1.

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

5. The first precursor contains terephthalaldehyde and the second precursor contains phenylenediamine. The method according to claim 4.

6. The method according to claim 1, further comprising etching the patterned surface to remove a portion of the carbon-containing film from the upper surface of the patterned surface. The method according to claim 1.

7. The method according to claim 1, further comprising repeating the method for forming a carbon-containing film having a thickness in the range of 0.1 nm to 50 nm. The method according to claim 1.

8. The carbon-containing film has a thickness in the range of 1 nm to 5 nm. The method according to claim 7.

9. Removing the first precursor comprises: Flowing a purge gas over the EUV photoresist; Removing a mixture of the first precursor effluent and the purge gas from the EUV photoresist. The method according to claim 1.

10. The patterned surface is an EUV photoresist pattern. The method according to claim 1.

11. The method according to claim 10, wherein the patterned surface comprises a mandrel. The method according to claim 10.

12. A method of depositing a carbon-containing film, comprising: Flowing a first precursor over an EUV photoresist comprising a patterned surface, wherein the first precursor has the general formula R １ -(X) ｎ and has R １ contains one or more of an alkyl group, an alkenyl group, an aryl group, an aromatic group, and a cycloalkyl group, and X ｎ contains one or more of a hydroxy group, an aldehyde group, a ketone group, an acidic group, an amino group, an isocyanate group, a thiocyanate group, and an acyl chloride group, and n is an integer in the range of 1 to 6, The first precursor reacts with a reactive group on the patterned surface to form a first portion of the carbon-containing film; Flowing a first precursor; Removing a first precursor effluent containing the first precursor from the EUV photoresist; Flowing a second precursor over the EUV photoresist, the second precursor having the general formula R ２ -(Y) ｎ and R ２ contains one or more of an alkyl group, an alkenyl group, an aryl group, an aromatic group, and a cycloalkyl group, and Y ｎ contains one or more of a hydroxy group, an aldehyde group, a ketone group, an acidic group, an amino group, an isocyanate group, a thiocyanate group, and an acyl chloride group, and n is an integer in the range of 1 to 6 The second precursor reacts with the first portion to form a conformal carbon-containing film; Flowing a second precursor; Removing a second precursor effluent containing the second precursor from the EUV photoresist; Etching the EUV photoresist to remove a portion of the carbon-containing film from the upper surface of the patterned surface. A method.

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

14. The first precursor comprises terephthalaldehyde and the second precursor comprises phenylenediamine. The method according to claim 13.

15. Removing the first precursor comprises: Flowing a purge gas over the EUV photoresist; Removing a mixture of the first precursor effluent and the purge gas from the EUV photoresist. The method according to claim 12.

16. The patterned surface is an EUV photoresist pattern, and the carbon-containing film is formed on the sidewalls to reduce line edge roughness (LER). The method according to claim 12.

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

18. Further comprising repeating the method for forming the carbon-containing film having a thickness in the range of 0.1 nm to 50 nm. The method according to claim 12.

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

20. A method for reducing line edge roughness (LER) of an EUV photoresist, comprising molecular layer deposition of a carbon-containing film on a patterned surface of the EUV photoresist, the molecular layer deposition comprising: 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 the 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 sidewalls of the EUV photoresist to reduce line edge roughness (LER). Method.

Images