Method for preparing a patterned resistant layer and resistant solution

Abstract

The present disclosure discloses a method for preparing a patterned photoresist layer and a photoresist solution, and particularly discloses various methods and materials for improving the hardness of a metal photoresist used in EUV optical lithography. A variety of different additive types for use with the metal photoresist are described. The additives can be applied to the photoresist as part of existing solutions or as an ingredient in a treatment solution during various steps for coating, patterning, and developing the metal photoresist. The resulting photoresist layer has an increased hardness and a higher EUV light sensitivity, which permits a reduced radiation dose.

Description

Technical Field

[0001] The present disclosure relates to a method for preparing a patterned photoresist layer and a photoresist solution. Background Art

[0002] Integrated circuits are formed on semiconductor wafers. An optical lithography patterning process uses ultraviolet light to transfer a mask pattern to a photoresist on the semiconductor wafer. An etching process can then be used to transfer the pattern to the layers below the photoresist. This process is repeated multiple times with different patterns to build up different layers on the wafer substrate and create useful devices.

[0003] High-resolution lithography processes are useful for achieving smaller feature sizes. An example of such a process is extreme ultraviolet (EUV) lithography, which uses wavelengths of about 10 nanometers (nm) to about 100 nm. Summary of the invention

[0004] According to some embodiments of the present disclosure, a method for preparing a patterned photoresist layer includes the following operations. A substrate is coated with a photoresist solution, and the photoresist solution includes a photoresist and an additive. The additive includes at least one cyclic ether group, or at least one alkenyl or alkynyl group, or at least one phosphonic acid group or silane group, or at least one acrylate group, or at least one thiol group, or at least one amine group, or at least one isocyanate group, or at least one ureide group, or at least one anhydride group, or at least one halogenated acyl group, or at least one acyl ester group; or the additive is an alkoxy melamine or an aromatic alcohol or ether.

[0005] According to some embodiments of the present disclosure, a photoresist solution comprises a metal photoresist and an additive. The additive comprises at least one cyclic ether group, or at least one alkenyl or alkynyl group, or at least one phosphonic acid group or silane group, or at least one acrylate group, or at least one thiol group, or at least one amine group, or at least one isocyanate group, or at least one ureide group, or at least one anhydride group, or at least one halogenated acyl group, or at least one acyl ester group; or the additive is an alkoxy melamine or an aromatic alcohol or ether.

[0006] According to some embodiments of the present disclosure, a method for preparing a patterned photoresist layer includes the following operations. A substrate is coated with a photoresist solution. The coated substrate is pre-baked to cure the photoresist solution and form a photoresist layer. The photoresist layer is exposed to radiation to pattern the photoresist layer. A post-exposure bake of the coated substrate is performed as needed. The patterned photoresist layer is developed using a developer. The photoresist solution or the developer includes an additive; or the coated substrate is treated with a treatment solution containing an additive during or after the coating, pre-baking, exposure, optional post-exposure baking or development step; and the additive includes at least one cyclic ether group, or at least one alkenyl or alkynyl group, or at least one phosphonic acid group or silane group, or at least one acrylate group, or at least one thiol group, or at least one amine group, or at least one isocyanate group, or at least one ureide group, or at least one anhydride group, or at least one halogenated acyl group, or at least one acyl ester group; or the additive is an alkoxy melamine or an aromatic alcohol or ether. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0008] Figure 1A is a flow chart illustrating a method for preparing a patterned photoresist layer and etching a semiconductor device layer according to some embodiments;

[0009] Figure 1B A second flow chart showing another aspect of the method;

[0010] Figure 2A For the substrate at the start Figure 1A and Figure 1B Cross-sectional view before the method;

[0011] Figure 2B The substrate and the first material layer on the substrate are again at the starting Figure 1A and Figure 1B Cross-sectional view before the method;

[0012] Figure 3 is a cross-sectional view of a substrate and two bottom layers applied on a first material layer;

[0013] Figure 4 is a cross-sectional view of a substrate and a photoresist layer applied on two bottom layers;

[0014] Figure 5 is a cross-sectional view of the substrate after exposure to radiation, wherein the photoresist layer now includes soluble regions and insoluble regions;

[0015] Figure 6 is a cross-sectional view of the substrate and the patterned photoresist layer after development;

[0016] Figure 7 is a cross-sectional view of the final structure and the patterned first material layer;

[0017] Figure 8 is an illustration of an extreme ultraviolet (EUV) optical lithography system for exposing a photoresist layer to EUV radiation, according to some embodiments.

[0018]

Explanation of symbols

[0019] 100: Method

[0020] 101: Optional heating step

[0021] 102: Optional Steps

[0022] 104: Optional Steps

[0023] 105: Steps

[0024] 106: Optional Steps

[0025] 110: Steps

[0026] 112: Optional Steps

[0027] 115: Steps

[0028] 120: Steps

[0029] 122: Optional Steps

[0030] 125: Steps

[0031] 126: Optional Step

[0032] 130: Optional Step

[0033] 132: Optional Steps

[0034] 134: Optional Steps

[0035] 140: Steps

[0036] 145: Steps

[0037] 146: Optional Steps

[0038] 200:Substrate

[0039] 202: First material layer

[0040] 204: Lower bottom layer

[0041] 206: Upper bottom layer

[0042] 210: Photoresist (PR) layer

[0043] 212: Soluble area

[0044] 214: Insoluble region

[0045] 215:Thickness

[0046] 800: Optical lithography system

[0047] 840: Extreme Ultraviolet (EUV) Light Source

[0048] 850: Irradiation stage

[0049] 852: Field facet mirror

[0050] 854: Relay mirror

[0051] 860: Photomask

[0052] 862: Surface membrane

[0053] 870: Projection optics module

[0054] 872: Mirror

[0055] 874: Mirror DETAILED DESCRIPTION

[0056] The following disclosure provides many different embodiments or examples for implementing the different features of the subject matter provided. Specific examples of components and configurations are described below to simplify the present disclosure. Of course, these components and configurations are only examples and are not intended to be restrictive. For example, in the following description, forming a first feature above or on a second feature may include an embodiment in which the first and second features are formed in direct contact, and may also include an embodiment in which additional features may be formed between the first and second features so that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numbers and / or letters in various examples. This repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or configurations discussed.

[0057] Additionally, spatially relative terms, such as "below," "beneath," "lower," "above," "upper," and the like, may be used herein for ease of description to describe the relationship of one element or feature to another element or feature as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0058] The numerical values ​​in the specification and claim range of this application should be understood to include the same numerical values ​​when reduced to the same significant figures, and the numerical values ​​that differ from the stated values ​​by less than the experimental error of the conventional measurement technology of the type described in this application to determine the values. All ranges disclosed herein include the stated endpoints.

[0059] The term "about" can be used to include any numerical value that can vary without changing the basic function of the value. When used with this range, "about" also discloses a range defined by the absolute values ​​of the two endpoints, for example, "about 2 to about 4" also discloses a range "from 2 to 4". The term "about" can refer to plus or minus 10% of the indicated number.

[0060] The term "alkyl" is used herein to refer to a radical consisting of a chain of carbon atoms that is completely saturated (ie, contains only single bonds). Alkyl radicals may be linear, branched or cyclic.

[0061] The term "aromatic" or "aromatic" refers to a group having a ring system containing an electron conjugated π system with multiple π electrons that obey Huckel's rule. The ring system is composed of carbon atoms and hydrogen atoms. Examples of aryl groups include phenyl (derived from benzene) and other polycyclic aromatic hydrogens, such as naphthyl (derived from naphthalene) or phenanthrenyl (derived from phenanthrene). In general, aryl groups are planar and uncharged.

[0062] The term "heteroaryl" refers to a cyclic radical consisting of carbon atoms, hydrogen atoms and heteroatoms within the radical ring, which is an aromatic radical. The heteroatom may be nitrogen, sulfur or oxygen. Exemplary heteroaryls include thienyl, pyridyl, furyl, pyrrolyl, indolyl and quinolyl. Depending on the context, the heteroaryl radical has the ability to form a single bond with one or two different non-hydrogen atoms. For example, the radicals -C4H3S and -C4H2S- can both be referred to as thienyl and should both be considered heteroaryl radicals. As used herein, a heteroaryl group has 5 to about 18 carbon atoms.

[0063] The term "alkenyl" as used herein refers to a radical consisting of a chain of carbon atoms containing at least one carbon-carbon double bond and which is not aromatic. The alkenyl radical may be linear, branched or cyclic.

[0064] The term "alkynyl" as used herein refers to a radical consisting of a chain of carbon atoms containing at least one carbon-carbon triple bond and which is not aromatic. Alkynyl radicals may be linear, branched or cyclic.

[0065] The term "vinyl" or "ethylene" as used herein specifically refers to a functional group having the formula -(C=C)- with a carbon-carbon double bond, wherein each carbon atom is bonded to two other carbon atoms and which is not an aromatic group. Vinyl groups are usually found in hydrocarbons (linear, branched or cyclic groups). Vinyl groups are able to participate in crosslinking reactions, and therefore the carbon-carbon double bonds present in aromatic groups are not considered vinyl groups.

[0066] The term "acetylene" or "ethynyl" as used herein specifically refers to a functional group having the formula -(C≡C)- with a carbon-carbon triple bond, wherein each carbon atom is bonded to another other atom and which is not an aromatic group. Acetylenes are usually found in hydrocarbons (linear, branched or cyclic groups).

[0067] The term "hydrocarbon" is used herein to refer to a radical consisting of a carbon chain that may be fully saturated or unsaturated, and is not an aromatic radical. Hydrocarbon radicals may be linear, branched or cyclic. Hydrogen atoms may be replaced by other radicals. Alkyl, alkenyl and alkynyl are subsets of hydrocarbons.

[0068] The term "halogen" as used herein refers to fluorine, chlorine, bromine and iodine.

[0069] The term "ether" refers to a free radical in which an oxygen atom is covalently bonded to two different carbon atoms.

[0070] The term "substituted" refers to the replacement of at least one carbon atom or hydrogen atom on the named free radical by a heteroatom or another functional group. An example of a substituted alkyl group is a perhaloalkyl group, in which the hydrogen atoms in the alkyl group are replaced by halogen atoms. Another example of a substituted alkyl group is tetrahydrofuran, in which the methylene group is replaced by an oxygen atom. Aryl and heteroaryl groups can be substituted by alkyl, alkenyl or alkynyl groups.

[0071] The present disclosure may refer to temperatures used for certain process steps. Note that these temperatures generally refer to the temperatures at which the heat source (e.g., furnace) is set, and do not necessarily refer to the temperatures that must be obtained by the material exposed to heat.

[0072] The term "ambient temperature" or "room temperature" refers to a temperature of 20°C to 25°C.

[0073] The present disclosure is about structures made of different layers. When the terms "on" or "over" are used with reference to two different layers (including a substrate), the terms indicate that only one layer is on the other layer. These terms do not require that the two layers are directly in contact with each other, and allow other layers to be between the two layers. For example, all layers of a structure may be considered to be "on a substrate," even though they are not all in direct contact with the substrate. The term "directly" may be used to indicate two layers that are in direct contact with each other without any layers in between. In addition, when it is mentioned that a process step is performed on a substrate, depending on the context, this should be interpreted as performing such a step on any layer that may also be present on the substrate.

[0074] The present disclosure relates to various methods for improving the operation of metal photoresists. In this regard, chemically amplified photoresists can be viewed as operating via a multi-step reaction mechanism. First, upon exposure to EUV radiation, the photoresist absorbs photons from the radiation. Second, secondary electrons are emitted by the photoresist, and hot electrons are also generated. Third, a photo-acid generator (PAG) reacts with these electrons to produce photoacid. Fourth, the photoacid diffuses through the photoresist matrix. Fifth and finally, the photoacid catalyzes the decomposition of acid-sensitive groups from the photoresist, also known as deprotection. The photoacid is not consumed in this reaction and can therefore catalyze multiple deprotection reactions. The deprotected photoresist differs in solubility from the original photoresist. This difference in photoresist between exposed and non-exposed areas allows patterning of the photoresist, which is used to build different layers on a wafer substrate. Metal photoresists include metal atoms to increase the photon absorption rate, i.e., the first step of the reaction mechanism. The patterned photoresist layer is then used as a mask for performing various processes, such as etching underlying layers or depositing new layers.

[0075] The present disclosure relates to methods and materials for increasing the hardness of the resulting metal photoresist layer and / or for reducing the radiation dose required for patterning metallized photoresists. The metal photoresist is exposed to an additive having a structure as described herein during a photoresist development process. The photoresist development process includes the following steps: coating the substrate, pre-baking or soft baking, radiation exposure, optional post-exposure baking, development, and optional hard baking. The additive may be applied during or between any of these process steps. The additive is triggered by hydrogen bonding and / or chemical bonding from an acid or base catalyst. The acid or base may be generated from an intrinsic acid / base or an acid / base generated by photons. The increased hardness provides better etch selectivity, better critical dimension (CD) control, and increases the achievable depth-to-width ratio. Initially, a metal photoresist is described. Next, an additive is described. Next, other components that may be present in a photoresist solution and methods for using the photoresist solution will be described.

[0076] Metal Photoresist

[0077] The metal photoresist disclosed herein comprises a metal core and one or more ligands attached to or linked to the metal core. The ligands may be attached to the metal core via covalent bonds, ionic bonds, or metallic bonds, or via van der Waals forces.

[0078] The metal core of the metal photoresist includes a metal element. The metal element may exist as a pure metal (i.e., an atom), an ion, a compound (e.g., a metal oxide, a metal nitride, a metal oxynitride, a metal silicide, a metal carbide, etc.), or as a core of multiple metal atoms. Desirably, the metal element has a high EUV light absorption rate. Examples of suitable metal elements include silver (Ag), cadmium (Cd), indium (In), tin (Sn), antimony (Sb), tellurium (Te), cesium (Cs), gold (Au), mercury (Hg), titanium (Ti), lead (Pb), bismuth (Bi), polonium (Po), astatine (At), barium (Ba), lanthanum (La), cerium (Ce), hafnium (Hf), zirconium (Zr), chromium (Cr), tungsten (W), molybdenum (Mo), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), zinc (Zn), aluminum (Al), gallium (Ga), thallium (Tl), and germanium (Ge). In more specific embodiments, the metal core of the metal photoresist comprises Ag, Cd, In, Sn, Sb, Te, Cs, Au, Hg, Ti, Pb, Bi, Po, At, Ba, La, or Ce. The metal element in the metal core of the metal photoresist may contain about 0.01 wt % to about 7 wt % of the photoresist solution. In some specific embodiments, only one metal element is present in the metal core. In other embodiments, multiple metal elements are present in the metal core.

[0079] The ligand is attached to the metal core, and this attachment determines whether the photoresist is soluble or insoluble when exposed to the developer. One function of the ligand is to protect the metal core from condensation prior to radiation exposure. In a particular embodiment, there are 1 to about 18 ligands attached to the metal core. In some embodiments, the ligand is hydrolyzable. Upon hydrolysis, the metal core can undergo a condensation reaction to form an organometallic polymer for the photoresist. In other embodiments, the ligand can be cleaved from the metal core during radiation exposure or heat treatment to allow the metal cores to crosslink with each other and form a metal photoresist.

[0080] The individual ligands themselves can be synthesized using conventional methods known in the art. The metal core can also be synthesized using conventional methods well known in the art. The ligands can be attached to the metal core using conventional methods well known in the art. Metal photoresists are suitable for EUV optical lithography processes that require a pitch of less than 40 nanometers (nm).

[0081] additive

[0082] During the photoresist development process, the metal photoresist can be exposed to additives to enhance the properties of the metal photoresist, particularly its hardness. In contrast to metal photoresists, additives do not contain metal. Thirteen different types or structures of additives are described herein. Please note that a given compound may belong to more than one type of additive, particularly when substituents are present. The additive is photosensitive. After exposure to radiation or heat, the additive may decompose and react with the photoresist, or the additive may crosslink, or the additive may polymerize. More than one additive type may be used in the photoresist development process when desired.

[0083] In certain embodiments, the additive has a molecular weight of about 30 to about 2000 Daltons (also referred to as atomic mass units or atomic mass units), although other values ​​or ranges are also within the scope of the present disclosure. In general, the additive typically contains a total of 1 to 30 carbon atoms or a minimum of 6 carbon atoms in some other embodiments, although other values ​​and ranges are also within the scope of the present disclosure.

[0084] The first type of additive (type 1) contains at least one cyclic ether group. Examples of cyclic ether groups include oxirane (C2O), oxetane (C3O), tetrahydrofuran (C4O) and tetrahydropyran (C5O). In certain embodiments, such additives may have a structure of formula (1-A) or formula (1-B):

[0085]

[0086] Where R 1 is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl;

[0087] Each R 2 are independently hydrocarbon or heteroatom-containing substituents;

[0088] m is an integer from 0 to 12;

[0089] Each L is -O-, -S-, a hydrocarbon, a substituted hydrocarbon, or a combination thereof;

[0090] Each R a and R b are independently alkylene groups having 0 to 3 carbon atoms, but together have a minimum of 2 carbon atoms;

[0091] Each R 3 are independently H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; and

[0092] n is an integer from 1 to 20.

[0093] Formula (1-B) includes oxetane (C3O), tetrahydrofuran (C4O) and tetrahydropyran (C5O), wherein the oxygen atom is located in any position relative to the linker L. 1 When not H, the cyclic ether group may be attached to any carbon atom or R 1 In some specific embodiments of formula (1-A) and formula (1-B), R 1 is an aryl or alkyl group having 1 to 20 carbon atoms. In other specific embodiments, each L is -O-, -S-, an alkyl group or a combination thereof. In additional specific embodiments of formula (1-B), R 3 is an alkyl group, a fluoroalkyl group, or an aryl group having 1 to 20 carbon atoms. Combinations of these embodiments are also contemplated.

[0094] R 2 Non-limiting examples of substituents may include halogen, -OH, -SH, -NO2, -SO2R, -SO3R, -CN, -COR, -CO2R, or -CONR2, wherein each R is independently hydrogen or alkyl.

[0095] Some non-limiting examples of type 1 additives containing one or more cyclic ether groups are shown below as formulas (1-1) to (1-4):

[0096]

[0097] Formula (1-1) corresponds to formula (1-A), where R 1 = benzene; m = 2, where each R 2 is ethyl; each L is -O-; and n=2. Formula (1-2) corresponds to formula (1-B), wherein R 1 = naphthalene; m = 0; each L is -O-; each R a and R b is a methylene group; and n=2. Formula (1-3) corresponds to formula (1-A), wherein R 1 = benzene; m = 0, wherein each L is -O-CH2-; and n = 3. Formula (1-4) corresponds to formula (1-A), wherein R 1 =C(CH2)4; m=0; each L is -O-; and n=4.

[0098] The second type of additive (type 2) contains at least one alkenyl group or at least one alkynyl group. In certain embodiments, such additives may have a structure of formula (2-A) or formula (2-B):

[0099]

[0100] Where R 1 is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl;

[0101] Each R 2 are independently hydrocarbon or heteroatom-containing substituents;

[0102] m is an integer from 0 to 12;

[0103] each L is -O-, -S-, a hydrocarbon, a substituted hydrocarbon, or a combination thereof; and

[0104] n is an integer from 1 to 20.

[0105] When R 1 When not H, alkenyl and alkynyl groups may be attached to any carbon atom or R 1 In some specific embodiments of formula (2-A) and formula (2-B), R 1 L is an aromatic group or an alkyl group having 1 to 20 carbon atoms. In other specific embodiments, each L is -O-, -S-, an alkyl group or a combination thereof. Combinations of these embodiments are also contemplated.

[0106] Furthermore, in formula (2-A) and formula (2-B), R 2 Non-limiting examples of substituents may include halogen, -OH, -SH, -NO2, -SO2R, -SO3R, -CN, -COR, -CO2R, or -CONR2, wherein each R is independently hydrogen or alkyl.

[0107] Some non-limiting examples of type 2 additives containing one or more alkenyl or alkynyl groups are shown below as formulas (2-1) to (2-5):

[0108]

[0109]

[0110] The structures of formula (2-2) and formula (2-5) are examples, wherein R 1 is a substituted hydrocarbon. In formula (2-2), the methylene group is substituted by an oxygen atom. In formula (2-5), the methylene group is substituted by an oxygen atom, and the hydrogen atom is substituted by an amino group.

[0111] The third type of additive (Type 3) is alkoxy melamine. In a specific embodiment, the alkoxy melamine has a structure of formula (3-A):

[0112]

[0113] wherein each R is independently H or And at least one R is

[0114] Each R 1are independently alkyl or substituted alkyl;

[0115] Each X is independently O or S; and

[0116] Each R 2 is H, alkyl, aryl or a combination thereof.

[0117] Melamine may have 1 to 6 isolated alkoxy chains. In a specific embodiment of formula (3-A), each R 2 Contains 1 to 20 carbon atoms. In some specific embodiments of formula (3-A), each R 2 is an alkyl group, a fluoroalkyl group or an aryl group having 1 to 20 carbon atoms. In a more specific embodiment of formula (3-A), each R 2 is H, methyl or benzyl (a combination of alkyl and aryl). In an even more specific embodiment of formula (3-A), R is hydroxymethyl.

[0118] Some non-limiting examples of Type 3 melamine additives are shown below as formulas (3-1) to (3-6):

[0119]

[0120] The fourth type of additive (type 4) contains at least one phosphate group or at least one silane group. In certain embodiments, such additives may have a structure of formula (4-A) or formula (4-B):

[0121]

[0122] wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl;

[0123] Each R 1 are independently hydrogen or alkyl; and

[0124] n is an integer from 1 to 20.

[0125] In some specific embodiments, each R 1 is hydrogen. In some more specific embodiments of formula (4-A) and formula (4-B), R is an alkyl group, a fluoroalkyl group, or an aryl group having 1 to 20 carbon atoms. Combinations of these embodiments are also contemplated. Some non-limiting examples of type 4 additives containing phosphate groups or silane groups are shown below as formulas (4-1) and (4-2):

[0126]

[0127] The fifth type of additive (type 5) is an aromatic alcohol or ether derivative. In certain embodiments, such additives may have a structure of formula (5-A):

[0128]

[0129] Where R 1 Contains one or more aryl or heteroaryl groups linked together by covalent bonds or alkyl groups;

[0130] Each R 2 are independently alkyl, fluoroalkyl, aryl or a substituent containing a heteroatom;

[0131] m is an integer from 0 to 12;

[0132] Each L is a hydrocarbon, a substituted hydrocarbon, or a combination thereof;

[0133] Each X is O or S;

[0134] Each R 3 are independently hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; and

[0135] n is an integer from 1 to 20.

[0136] In some specific embodiments of formula (5-A), each R 3 is an alkyl group, a fluoroalkyl group or an aryl group having 1 to 20 carbon atoms. 1 is an aromatic group such as benzene, naphthalene, anthracene or phenanthrene. Combinations of these embodiments are also contemplated. Substituents (indicated by m and n) may be attached to any carbon atom or R 1 Suitable heteroatoms include:

[0137] Some non-limiting examples of Type 5 additives containing aromatic alcohol or ether groups are shown below as formulas (5-1) to (5-6):

[0138]

[0139] Formula (5-1) corresponds to formula (5-A), where R 1 =benzene; each L is -CH2-; each X is O, each R 3 =H; n = 2; R 2 = n-butyl; and m = 1. Formula (5-2) corresponds to formula (5-A), wherein R 2 = n-propoxy; and m = 1. In formula (5-3), n = 3, containing two alcohol groups and one ether group; and m = 3, wherein R 2 is two methyl groups and one trifluoromethyl group. In formula (5-4), R 1 = biphenyl (a combination of two aromatic groups linked together via a covalent bond); n = 4, with four alcohol groups; and m = 2, where R 2 is one n-propyl group and one isopropyl group. In formula (5-5), R 1 = phenanthrene; n = 3, with three alcohol groups; and m = 3, wherein R 2is one n-propyl group and two isopropyl groups. In formula (5-6), R 1 = two naphthyl groups linked together via a methylene group; and n = 5, with five alcohol groups.

[0140] The sixth type of additive (type 6) contains at least one acrylic acid group. In a specific embodiment, this type of additive has a structure of formula (6-A):

[0141]

[0142] wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl, or a combination thereof linked together by a covalent bond or an alkyl group;

[0143] Each R 1 are independently hydrogen or alkyl; and

[0144] n is an integer from 1 to 20.

[0145] In some specific embodiments of formula (6-A), R is an alkyl group, a fluoroalkyl group, or an aryl group having 1 to 20 carbon atoms. 1 Each acrylic acid group may be attached to any carbon atom or R 1 Combinations of these embodiments are also contemplated.

[0146] Some non-limiting examples of Type 6 additives containing one or more acrylic groups are shown below as formulas (6-1) to (6-3):

[0147]

[0148] The seventh type of additive (Type 7) contains at least one thiol group. In a specific embodiment, this type of additive has a structure of formula (7-A):

[0149] R-(SH) n Formula (7-A)

[0150] wherein R is a hydrocarbon, a substituted hydrocarbon, an aryl or a heteroaryl, or a combination thereof that may be linked together via a covalent bond or an alkyl group; and

[0151] n is an integer from 1 to 20.

[0152] hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; and

[0153] n is an integer from 1 to 20.

[0154] In some specific embodiments of formula (7-A), R is an alkyl, fluoroalkyl, or aryl group having 1 to 20 carbon atoms. Each thiol may be attached to any carbon atom or suitable heteroatom of R. A non-limiting example of a type 7 additive containing one or more thiol groups is shown below as formula (7-1), wherein R is toluene and n=2:

[0155]

[0156] The eighth type of additive (type 8) contains at least one amine group. In certain embodiments, such additives may have a structure of formula (8-A):

[0157] R-(NHR 1 ) n Formula (8-A)

[0158] wherein R is a hydrocarbon, a substituted hydrocarbon, an aryl or a heteroaryl, or a combination thereof that may be linked together via a covalent bond or an alkyl group; and

[0159] n is an integer from 1 to 20.

[0160] In some specific embodiments of formula (8-A), R is an alkyl group, a fluoroalkyl group, or an aryl group having 1 to 20 carbon atoms. 1 Each amine group may be attached to any carbon atom or suitable heteroatom of R. Combinations of these embodiments are also contemplated. A non-limiting example of a type 8 additive containing one or more amine groups is shown below as formula (8-1), which contains one -NH2 group and one amine group, wherein R 1 For ethyl:

[0161]

[0162] The ninth type of additive (type 9) contains at least one isocyanate group. In certain embodiments, such additives may have a structure of formula (9-A):

[0163] R-(NCO) n Formula (9-A)

[0164] wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl, or a combination thereof that may be linked together via a covalent bond or an alkyl group; and

[0165] n is an integer from 1 to 20.

[0166] In some specific embodiments of formula (9-A), R is an alkyl, fluoroalkyl, or aryl group having 1 to 20 carbon atoms. Each isocyanate group may be attached to any carbon atom or suitable heteroatom of R. A non-limiting example of a type 9 additive containing one or more isocyanate groups is shown below as formula (9-1), which contains two isocyanate groups and wherein R is a combination of two aryl groups linked together via an alkyl group:

[0167]

[0168] The tenth type of additive (type 10) contains at least one ureide group. In certain embodiments, such additives may have a structure of formula (10-A):

[0169]

[0170] wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl, or a combination thereof that may be linked together via a covalent bond or an alkyl group; and

[0171] n is an integer from 1 to 20.

[0172] In some specific embodiments of formula (10-A), R is an alkyl group, a fluoroalkyl group, or an aryl group having 1 to 20 carbon atoms. Each ureide group may be attached to any carbon atom or a suitable heteroatom of R.

[0173] The eleventh type of additive (type 11) contains at least one anhydride group. In certain embodiments, such additives may have a structure of formula (11-A) or formula (11-B):

[0174]

[0175] wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl, or a combination thereof that may be linked together via a covalent bond or an alkyl group;

[0176] Each R a are independently alkylene groups having at least 1 carbon atom; and

[0177] n is an integer from 1 to 20.

[0178] In a specific embodiment of formula (11-A), R ais an alkylene radical having 1 to 20 carbon atoms. As can be seen in formula (11-B), the anhydride group can be attached to the R group via one or more carbon atoms. In some specific embodiments of formula (11-A) and formula (11-B), R is an alkyl group, a fluoroalkyl group, or an aryl group having 1 to 20 carbon atoms. Combinations of these embodiments are also contemplated. Each anhydride group can be attached to any carbon atom or a suitable heteroatom of R. The structures of formula (11-A) and formula (11-B) should also be interpreted as including compounds having two carboxylic acid groups.

[0179] A non-limiting example of a type 11 additive containing anhydride groups is shown below as formula (11-1), which corresponds to formula (11-B) where R is cyclohexane, and n=2:

[0180]

[0181] The twelfth type of additive (type 12) contains at least one halogenated acyl group. In certain embodiments, such additives may have a structure of formula (12-A):

[0182]

[0183] wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl, or a combination thereof that may be linked together via a covalent bond or an alkyl group;

[0184] Each X is independently halogen; and

[0185] n is an integer from 1 to 20.

[0186] In some specific embodiments of formula (12-A), R is an alkyl, fluoroalkyl, or aromatic group having 1 to 20 carbon atoms. In other specific embodiments, X is chlorine. Combinations of these embodiments are also contemplated. Each halogenated acyl group may be attached to any carbon atom or suitable heteroatom of R. A non-limiting example of a type 12 additive containing one or more halogenated acyl groups is shown below as formula (12-1), wherein R is cyclohexane and n=3:

[0187]

[0188]

[0189] The thirteenth type of additive (type 13) contains at least one acyl ester group. In certain embodiments, such additives may have a structure of formula (13-A):

[0190]

[0191] wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl, or a combination thereof that may be linked together via a covalent bond or an alkyl group;

[0192] Each R 1 are independently hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; and

[0193] n is an integer from 1 to 20.

[0194] In some specific embodiments of formula (13-A), R is an alkyl group, a fluoroalkyl group, or an aryl group having 1 to 20 carbon atoms. In other specific embodiments of formula (13-A), each R 1 is an alkyl, fluoroalkyl or aryl group having 1 to 20 carbon atoms. Combinations of these embodiments are also contemplated. A non-limiting example of a type 13 additive containing one or more acyl ester groups is shown below as formula (13-1), wherein R is benzene, n=2 and R 1 is ethyl;

[0195]

[0196] The additives themselves can be synthesized using conventional methods known in the art.

[0197] In certain embodiments, the additive may be used in an amount of about 0.1 wt % to about 20 wt % relative to the metal photoresist. As will be described in further detail herein, the photoresist development process includes the following steps: coating the substrate, pre-baking or soft-baking, radiation exposure, optional post-exposure baking, developing, and optional hard baking. The additive may be used during any of these process steps, or may be used between any of the process steps. Depending on the operating temperature and pressure of the particular process step, the additive may be provided in a liquid phase or a gas / vapor phase or as a solid.

[0198] Photoresist solution or treatment solution

[0199] Photoresist solutions are commonly used to prepare photoresist layers on semiconductor wafer substrates. The photoresist solution includes a metal photoresist as described above. The photoresist solution may also include a cross-linking agent as known in the art. The photoresist solution also includes a solvent in which the photoresist and the cross-linking agent are carried. The solvent may be, for example, water, propylene glycol methyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), 1-ethoxy-2-propanol (PGEE), γ-butyrolactone (GBL), cyclohexanone (CHN), ethyl lactate (EL), methanol, ethanol, propanol, n-butanol, acetone, methyl ethyl ketone, dimethylformamide (DMF), isopropanol (IPA), tetrahydrofuran (THF), methyl isobutyl carbinol (MIBC), n-butyl acetate (nBA), 2-heptanone (MAK), isobutyl propionate, or other suitable solvents.

[0200] The metal photoresist may include about 0.1 wt % to about 50 wt % of the photoresist solution. The crosslinker may include about 0.1 wt % to about 20 wt % of the photoresist solution. The remainder of the photoresist solution is a solvent.

[0201] In some embodiments, the metal element in the metal core of the metal photoresist may comprise about 0.01 wt % to about 7 wt % of the photoresist solution. Any crosslinking agent is generally used in an amount of about 0.1 wt % to about 30 wt % relative to the metal photoresist.

[0202] The photoresist solution may also include a photoacid generator (PAG). After exposure to radiation, the photoacid generator decomposes to produce acid. The photoresist solution may also include a thermal acid generator (TAG). At high temperatures, the thermal acid generator decomposes to produce acid. The acid catalyzes a chemical reaction that changes the solubility of the photoresist, for example by cleaving ligands from the metal core. The additive will also be triggered by the acid. Photobase generators (PBG) and thermal base generators (TBG) may also be used, which may also trigger the additive. Quenchers may also be present to enhance the patterning solution by neutralizing the acid that may diffuse into the non-exposed areas of the photoresist.

[0203] When the additives of the present disclosure are not included in the photoresist solution, the additives are typically provided in liquid form as a treatment solution. The solvent of the treatment solution can be any of the same solvents as the solvent used in the photoresist solution. The additives can be dissolved in the solvent to a saturated state to form the treatment solution. In some embodiments, the additives can be dissolved to a final concentration of about 0.0001 wt % to about 99 wt %. Other values ​​and ranges are also within the scope of the present disclosure.

[0204] Technology

[0205] Figure 1A is a flow chart illustrating a method 100 for preparing a patterned photoresist layer and etching a layer of a semiconductor device, according to some embodiments. Figure 1B is another flow chart of another aspect of the illustrated method. In the following discussion, Figure 1A Some steps of the method are also shown in the figure Figures 2A to 7 These figures provide different views for better understanding.

[0206] First see Figure 2A , which illustrates an example of a starting state of substrate 200 prior to any processing steps. The substrate is typically a wafer made of a semiconductor material. Such materials may include, for example, silicon in the form of crystalline Si or polycrystalline Si. In alternative embodiments, the substrate may be made of other elemental semiconductors such as germanium, or may include compound semiconductors such as silicon carbide (SiC), gallium arsenide (GaAs), gallium carbide, gallium phosphide, indium arsenide (InAs), indium phosphide (InP), silicon germanium, silicon germanium carbide, gallium arsenic phosphide, or gallium indium phosphide. In a specific embodiment, the semiconductor substrate is silicon. As illustrated here, no additional layers are present on substrate 200.

[0207] In comparison, Figure 2A, a first material layer 202 is present on a substrate 200. The first material layer may be any material that may be used in a semiconductor device or integrated circuit. For example, the first material layer may be made of an insulating material such as silicon dioxide (SiO2) or silicon nitride (SiN), silicon oxynitride (SiON), fluorine-doped silicate glass, or other dielectric material. As another example, the first material layer may be made of a conductive material such as polysilicon, or a metal such as aluminum, copper, titanium, or tungsten. The following discussion continues with the first material layer present for illustrative purposes only and with the understanding that the substrate may also be etched.

[0208] It may be desirable to heat the substrate prior to initiating the photoresist patterning process. This optional heating step 101 can improve resist adhesion by desorbing water present on the substrate surface and thermally breaking any hydrogen-oxygen bonds present on the oxidized surface. The substrate may be heated to a temperature above 100° C. up to, for example, 200° C. for a period of, for example, several minutes. The substrate is then cooled back to room temperature.

[0209] See again Figure 1A In optional step 102, one or more bottom layers are applied to the substrate. In this context, the term "bottom layer" is relative to the photoresist layer and refers to any layer that may be applied to the layer to be etched before the photoresist layer is applied. In other words, any layer between the layer to be etched and the photoresist layer may be considered a bottom layer. Figure 3 In one non-limiting example, two bottom layers 204 , 206 are applied to a first material layer 202 .

[0210] As an example, the lower bottom layer 204 may be a bottom anti-reflective coating (BARC). When a photoresist layer is applied to a reflective substrate, light reflection from the substrate / resist interface may produce variations in light exposure that cause problems in critical dimension (CD) control. For example, light may be reflected into areas where exposure is not desired, thereby changing the desired pattern. BARC may be applied between the substrate and the photoresist layer to minimize or eliminate such problems. Examples of suitable BARC include amorphous carbon and various organic polymers. The BARC layer is typically formed by spin coating, although other methods may also be used. The BARC coating or film is then baked or cured to induce crosslinking and solvent removal and hardening of the BARC. In some specific embodiments, baking occurs at a temperature of about 125° C. to about 275° C. In a specific embodiment, baking occurs for a period of about 30 seconds to about 250 seconds. Baking may be performed using a hot plate or similar equipment.

[0211] As another example, the upper bottom layer 206 may be a hard mask layer. The hard mask layer may be formed of a dielectric material, a metal, or other suitable material. Examples of suitable dielectric materials may include silicon carbide, silicon nitride, silicon oxycarbide, or silicon oxynitride. The hard mask layer may be formed by any suitable process such as chemical vapor deposition (CVD), low-pressure CVD (LPCVD), plasma-enhanced CVD (PECVD), physical vapor deposition (PVD), atomic layer deposition (ALD), or spin coating. The BARC layer and the hard mask layer are also typically selected to have significantly different etch selectivities for the same etchant. In combination with the photoresist layer, this multi-layer resist pattern may also help improve line width roughness (LWR).

[0212] When using the bottom layer, such as Figure 1A The additive may be mixed with the material of the underlying layer or applied to any underlying layer, as indicated in optional step 104 of . This may be accomplished, for example, by applying the additive in a liquid phase (e.g., solution) or a gas phase during baking / curing of the underlying layer. Alternatively, the additive may be applied as a solid.

[0213] Then, in Figure 1A In step 105, Figure 4 As shown in FIG, a photoresist (PR) layer 210 is applied over the substrate. The photoresist layer is formed by applying a photoresist solution containing a metal photoresist and / or an additive. The photoresist solution can be applied, for example, by spin coating or by spraying, roller coating, dip coating, or extrusion coating. Generally speaking, in spin coating, the substrate is placed on a rotating platform, which may include a vacuum chuck that holds the substrate in a plate. The photoresist solution is then applied to the center of the substrate. The speed of the rotating platform is then increased so that the resist is evenly distributed from the center of the substrate to the periphery of the substrate. The rotation speed of the platform is then fixed, and the rotation speed can control the thickness of the final photoresist layer. Figure 4 The resulting structure after this step is depicted.

[0214] Alternatively, if Figure 1A In the optional step 106 of , the additive may be applied after the photoresist layer has been applied. Again, the additive may be applied in a liquid phase, for example by spin coating or spraying or misting a solution onto the photoresist layer. Alternatively, the additive may be applied as a solid or gas.

[0215] Then, in Figure 1AIn step 110, the photoresist solution is pre-baked to remove the solvent and harden the photoresist layer. This may also be referred to as a soft bake. In some specific embodiments, the pre-bake occurs at a temperature of about 40°C to about 100°C, including from about 250°C to about 800°C or from about 90°C to about 110°C. The time of the pre-bake may depend on the thickness of the photoresist layer 210, with a longer time for greater thicknesses and in specific embodiments from about 10 seconds to about 10 minutes. See FIG. Figure 4 , the photoresist layer 210 may have a thickness 215 of about 10 nanometers to about 100 nanometers. Baking may be performed using a hot plate or oven or similar equipment. Thus, a photoresist layer is formed on the substrate. The substrate and other layers thereon are then cooled to room temperature.

[0216] like Figure 1A The additive may be applied during or after pre-baking, as indicated in optional step 112 of . The additive may be applied as a liquid, or may be evaporated by the heat generated in the pre-baking step and applied as a gas. Alternatively, the additive may be applied as a solid.

[0217] Continuing, in Figure 1A In step 115, the photoresist layer 210 is then patterned by exposure to radiation. The radiation can be any wavelength of light that carries the desired mask pattern. In a specific embodiment, EUV light having a wavelength of about 13.5nm is used for patterning because this allows smaller feature sizes to be obtained. In other embodiments, electron-beam (e-beam) radiation is used. The electron beam can be characterized by the energy of the beam, which in some embodiments ranges from about 5 volts (V) to about 200 kilovolts (kV). This step causes some portions of the photoresist layer to be exposed to the radiation, and some portions of the photoresist are not exposed to the radiation. This exposure causes some portions of the photoresist to remain soluble in the developer, and other portions of the photoresist to become insoluble in the developer. See now Figure 5 , the photoresist layer 210 now includes soluble regions 212 and insoluble regions 214. For reference purposes, it is noted that EUV and electron beam radiation exposure typically occurs under vacuum.

[0218] Prior to radiation exposure or heat exposure, the additive does not react with the metal photoresist. When exposed to radiation or heat, the additive reacts with the metal photoresist or with itself (including other additives if more than one of the 13 types of additives described above is used).

[0219] As necessary, Figure 1AIn step 120, a post exposure bake (PEB) occurs after exposure to radiation. The PEB step can be used to complete any crosslinking within the photoresist. In addition, the PEB step can reduce mechanical stress that may have accumulated during the previous technical steps. In some specific embodiments, the PEB occurs at a temperature of about 40°C to about 250°C, including from about 100°C to about 250°C or from about 90°C to about 150°C. The time range of the PEB can be about 10 seconds to about 10 minutes, and can vary depending on the thickness of the photoresist layer.

[0220] like Figure 1A The additives may be applied during or after the post-exposure bake, as indicated in optional step 122 of . The additives may be applied as a liquid, or evaporated during the heating that occurs in the PEB step to enter a gas phase, or applied as a solid.

[0221] Then, in Figure 1A In step 125, the photoresist layer 210 is developed using a developer. The developer can be applied by spin coating, spraying or other suitable processes. The soluble portion of the photoresist layer is dissolved and rinsed off during the development step, leaving a patterned photoresist layer. This can be done, for example, by centrifugal drying. Suitable developers may include PGMEA, PGME, PGEE, GBL, cyclohexanone, ethyl lactate, methanol, ethanol, propanol, n-butanol, acetone, DMF, isopropyl alcohol (IPA), THF, MIBC, n-butyl acetate, MAK or isobutyl propionate, that is, the same solvent used in the photoresist solution. Other developers may include aqueous tetramethylammonium hydroxide (TMAH), isoamyl acetate, cyclohexanone, 5-methyl-2-hexanone, methyl-2-hydroxyisobutyrate, n-amyl ester, n-butyl propionate, n-hexyl acetate, n-butyl butyrate, isobutyl butyrate, 2,5-dimethyl-4-hexanone, 2,6-dimethyl-4-heptanone, propyl isobutyrate, or isobutyl propionate. In general, any suitable developer may be used.

[0222] If desired, the additives may be mixed directly into the developer. Figure 1A The additive may be applied after the developer has been applied and the substrate is then rinsed with water, as indicated in optional step 126 of . Again, the additive may be applied in a liquid phase, such as by spin coating or spraying or atomizing a solution, or may be applied as a solid or gas. The resulting structure is shown in FIG. Figure 6 As can be seen here, the soluble areas have been washed away, resulting in a patterned photoresist layer.

[0223] exist Figure 1AIn optional step 130 of the present invention, a post-development bake or "hard bake" may be performed after development. This may be performed after development to stabilize the photoresist pattern for optimal execution of subsequent steps. In some specific embodiments, the hard bake occurs at a temperature of about 100° C. to about 160° C. The time for the hard bake may range from about 1 minute to about 10 minutes and may vary depending on the thickness of the photoresist layer.

[0224] like Figure 1A The additive may be applied during or after the hard bake, as indicated in optional step 132 of . The additive may be applied as a liquid (ie, a treatment solution), or evaporated during the heating that occurs in the hard bake step to enter a gas phase, or applied as a solid.

[0225] Various baking steps may be used to enhance the reaction of the additive with itself or with the metal photoresist. In some embodiments, the baking step may occur at any temperature ranging from about 40°C to about 300°C.

[0226] Continuing, the portions of the upper bottom layer 206 , the lower bottom layer 204 , and the first material layer 202 exposed below the first patterned photoresist layer are now exposed.

[0227] exist Figure 1A In optional step 134, the bottom layers 204, 206 are etched, thereby transferring the photoresist pattern to the bottom layers. Figure 1A In step 140, the first material layer 202 is etched, thereby transferring the photoresist pattern to the first material layer. Desirably, each of the etchants used for these layers is significantly different from the etchants used for the other layers, which improves the LWR in the first material layer.

[0228] Generally speaking, these etching steps may be performed using wet etching, dry etching or plasma etching processes, such as reactive ion etching (RIE) or inductively coupled plasma (ICP), or a combination thereof as appropriate. The etching may be anisotropic. Depending on the material, the etchant may include carbon tetrafluoride (CF4), hexafluoroethane (C2F6), octafluoropropane (C3F8), carbon fluoride (CHF3), difluoromethane (CH2F2), fluoromethane (CH3F), trifluoromethane (CHF3), carbon fluoride, nitrogen (N2), hydrogen (H2), oxygen (O2), argon (Ar), xenon (Xe), xenon difluoride (XeF2), helium (He), carbon monoxide (CO), carbon dioxide (CO2), fluorine (F2), chlorine (Cl2), oxygen (O2), hydrogen bromide (HBr), hydrofluoric acid (HF), nitrogen trifluoride (NF3), sulfur hexafluoride (SF6), boron trichloride (BCl3), ammonia (NH3), bromine (Br2), nitrogen trifluoride (NF3), the like, or a combination thereof, in various ratios. For example, silicon dioxide may be wet etched using hydrofluoric acid and ammonium fluoride. Alternatively, silicon dioxide can be dry etched using various mixtures of CHF3, O2, CF4 and / or H2.

[0229] View now Figure 1B , the two different treatment parts are more clearly depicted here. In the photoresist coating step 105 and the development step 125, the additive can be mixed directly into the photoresist solution or the developer solution. This is indicated by dotted lines. Alternatively, the additive can be used in the form of a treatment solution, which is applied to the photoresist. More preferably, the additive is used before, during or after the step of adding energy to the photoresist. Those steps include a radiation exposure step 115, which adds light energy or heat energy, a pre-bake step 110, and a post-exposure bake step 120. This is indicated by solid lines.

[0230] Then, in Figure 1A In step 145, the patterned photoresist layer 210 is removed. In optional step 146, the upper bottom layer 206 is removed. In optional step 148, the lower bottom layer 204 is removed. The photoresist layer, the upper bottom layer, and the lower bottom layer may be removed using conventional means such as plasma stripping, solvents, or chemical-mechanical planarization (CMP). The resulting structure is shown in FIG. Figure 7 In the embodiment, the first material layer 202 is patterned.

[0231] Figure 8is a pictorial diagram, not drawn to scale, illustrating various components of an extreme ultraviolet (EUV) optical lithography system that produces radiation to which a photoresist is exposed. Generally, an EUV optical lithography system 800 begins with an EUV light source 840 that produces EUV light or radiation. Downstream of the EUV light source is an illumination stage 850, where the EUV light may be collected and focused into a beam, for example, using a field facet mirror 852 that splits the beam into a plurality of light channels. These light channels may then be directed onto a plane of a reticle using one or more relay mirrors 854. The reticle 860 may include a pellicle 862 through which the radiation passes before and / or after contacting the reticle. Downstream of the reticle 860 is a projection optics module 870 that is configured to image the pattern of the reticle onto the semiconductor wafer substrate 200. The projection optics module 870 may include refractive optics or reflective optics for carrying an image of the pattern defined by the reticle. Illustrative mirrors 872, 874 are shown. Wafer substrate 200 is positioned on wafer stage 880, which can be moved when necessary for imaging. The lithography system may include other modules, or be integrated or coupled with other modules.

[0232] Additional processing steps may be performed to fabricate semiconductor devices or integrated circuits. Examples of these steps may include ion implantation, deposition of other materials, etching, etc.

[0233] The use of specified additives during the photoresist development process provides certain advantages. The hardness of the metal photoresist layer can be increased by 1% or more. In some specific embodiments, the resulting hardness of the metal photoresist layer is from about 0.01 GPa to about 100 GPa, although other ranges and values ​​are within the scope of the present disclosure. Line width roughness (LWR) and critical dimension uniformity (CDU) can be improved by 3% or more. The optimum energy (Eop) of lithography can also be improved by 3% or more. The metal photoresist can also have improved thermal stability, which also improves pattern fidelity. Processes with pitches of 40 nanometers or less can be improved using these components in the photoresist.

[0234] Some embodiments of the present disclosure are therefore related to methods for preparing a patterned photoresist layer. A substrate is coated with a photoresist solution, the photoresist solution comprising a photoresist and an additive. In some embodiments, the additive comprises at least one cyclic ether group, or at least one alkenyl or alkynyl group, or at least one phosphonic acid group or silane group, or at least one acrylate group, or at least one thiol group, or at least one amine group, or at least one isocyanate group, or at least one ureide group, or at least one anhydride group, or at least one halogenated acyl group, or at least one acyl ester group. In some other embodiments, the additive is an alkoxy melamine or an aromatic alcohol or ether.

[0235] In some embodiments, the additive has a structure of Formula (1-A) or Formula (1-B): Where R 1 is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; each R 2 are independently hydrocarbon or a substituent containing a heteroatom; m is an integer from 0 to 12; each L is -O-, -S-, hydrocarbon, substituted hydrocarbon or a combination thereof; each R a and R b are independently alkylene groups having 0 to 3 carbon atoms, but together have a minimum of 2 carbon atoms; each R 3 are independently H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; and n is an integer from 1 to 20.

[0236] In some embodiments, the additive has a structure of Formula (2-A) or Formula (2-B): Where R 1 is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; each R 2 are independently hydrocarbon or a substituent containing a heteroatom; m is an integer from 0 to 12; each L is —O—, —S—, hydrocarbon, substituted hydrocarbon or a combination thereof; and n is an integer from 1 to 20.

[0237] In some embodiments, the additive has a structure of formula (3-A): wherein each R is independently H or And at least one R is Each R 1 is independently alkyl or; each X is independently O or S; and each R 2 is H, alkyl, aryl or a combination thereof.

[0238] In some embodiments, the additive has a structure of Formula (4-A) or Formula (4-B): wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; each R 1are independently hydrogen or alkyl; and n is an integer from 1 to 20.

[0239] In some embodiments, the additive has a structure of formula (5-A): Where R 1 Contains one or more aryl or heteroaryl groups which may be linked together via a covalent bond or an alkyl group; each R 2 are independently alkyl, fluoroalkyl, aryl or a substituent containing a heteroatom; m is an integer from 0 to 12; each L is a hydrocarbon, a substituted hydrocarbon or a combination thereof; each X is O or S; each R 3 is a hydrocarbon, a substituted hydrocarbon, an aryl group or a heteroaryl group; and n is an integer from 1 to 20.

[0240] In some embodiments, the additive has a structure of formula (6-A): wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl, or a combination thereof linked together by a covalent bond or an alkyl group; each R 1 are independently hydrogen or alkyl; and n is an integer from 1 to 20.

[0241] In some embodiments, the additive has a structure of formula (7-A): R-(SH) n Formula (7-A), wherein R is a hydrocarbon, a substituted hydrocarbon, an aryl group or a heteroaryl group, or a combination thereof that can be linked together via a covalent bond or an alkyl group; and n is an integer from 1 to 20.

[0242] In some embodiments, the additive has a structure of formula (8-A): R-(NHR 1 ) n Formula (8-A), wherein R is a hydrocarbon, a substituted hydrocarbon, an aryl group or a heteroaryl group, or a combination thereof that can be linked together via a covalent bond or an alkyl group; and n is an integer from 1 to 20.

[0243] In some embodiments, the additive has a structure of formula (9-A): R—(NCO) n Formula (9-A), wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl, or a combination thereof linked together via a covalent bond or an alkyl group; and n is an integer from 1 to 20.

[0244] In some embodiments, the additive has a structure of formula (10-A): wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl, or a combination thereof linked together via a covalent bond or an alkyl group; and n is an integer from 1 to 20.

[0245] In some embodiments, the additive has a structure of Formula (11-A) or Formula (11-B): wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl, or a combination thereof linked together by a covalent bond or an alkyl group; each R a is independently an alkylene group having at least 1 carbon atom; and n is an integer from 1 to 20.

[0246] In some embodiments, the additive has a structure of formula (12-A): wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl, or a combination thereof linked together by a covalent bond or an alkyl group; each X is independently a halogen; and n is an integer from 1 to 20.

[0247] In some embodiments, the additive has a structure of formula (13-A): wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl, or a combination thereof linked together by a covalent bond or an alkyl group; each R 1 are independently hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; and n is an integer from 1 to 20.

[0248] In some embodiments, the additive has a molecular weight of about 30 to about 2,000.

[0249] In some embodiments, the method for preparing a patterned photoresist layer further comprises the following operations: Pre-baking the applied photoresist solution to form a photoresist layer. Exposing the photoresist layer to radiation to pattern the photoresist layer. Developing the photoresist layer to obtain a patterned photoresist layer.

[0250] Other embodiments of the present disclosure are related to a photoresist solution comprising a metal photoresist and an additive. In some embodiments, the additive comprises at least one cyclic ether group, or at least one alkenyl or alkynyl group, or at least one phosphonic acid group or silane group, or at least one acrylate group, or at least one thiol group, or at least one amine group, or at least one isocyanate group, or at least one ureide group, or at least one anhydride group, or at least one halogenated acyl group, or at least one acyl ester group. In some other embodiments, the additive is an alkoxy melamine or an aromatic alcohol or ether.

[0251] In some embodiments, the additive has a molecular weight of about 30 to about 2,000.

[0252] Finally, other embodiments of the present disclosure are directed to methods of using a photoresist solution. A substrate is coated with a photoresist solution. The coated substrate is prebaked to cure the photoresist solution and form a photoresist layer. The photoresist layer is then exposed to radiation to pattern the photoresist layer. An optional post-exposure bake of the coated substrate may be performed. The patterned photoresist layer is then developed using a developer. The photoresist solution or the developer may include an additive. Alternatively, the coated substrate is treated with a treatment solution containing the additive during or after the coating, prebaking, exposure, optional post-exposure bake, or development step. In some embodiments, the additive comprises at least one cyclic ether group, or at least one alkenyl or alkynyl group, or at least one phosphonic acid group or silane group, or at least one acrylate group, or at least one thiol group, or at least one amine group, or at least one isocyanate group, or at least one ureide group, or at least one anhydride group, or at least one halogenated acyl group, or at least one acyl ester group. In some other embodiments, the additive is an alkoxy melamine or an aromatic alcohol or ether.

[0253] In some embodiments, the additive is triggered by an acid or a base.

[0254] Additional embodiments of the present disclosure are directed to additives that can be used to increase the hardness of metal photoresists. In some embodiments, the additive comprises at least one cyclic ether group, or at least one alkenyl or alkynyl group, or at least one phosphonic acid group or silane group, or at least one acrylate group, or at least one thiol group, or at least one amine group, or at least one isocyanate group, or at least one ureide group, or at least one anhydride group, or at least one halogenated acyl group, or at least one acyl ester group. In some other embodiments, the additive is an alkoxy melamine or an aromatic alcohol or ether.

[0255] Other embodiments of the present disclosure are directed to a metal photoresist layer with enhanced hardness. The metal photoresist layer is further hardened by applying additives (as described above) and subsequent radiation exposure. Various reactions can occur to harden the metal photoresist layer.

[0256] In some embodiments, a wafer substrate having a hardened metal photoresist layer thereon is also disclosed. The hardened metal photoresist layer is produced as described above.

[0257] Also disclosed herein is an optical lithography system having wafer substrates having a hardened metal photoresist layer thereon. The optical lithography system includes an EUV light source, an irradiation stage, a photomask, a projection optics module, and a wafer stage on which the wafer substrate rests.

[0258] The foregoing summarizes the features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art will appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for implementing the same purposes and / or achieving the same advantages of the embodiments introduced herein. Those skilled in the art will also recognize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and such equivalent constructions may be variously modified, substituted, and replaced herein without departing from the spirit and scope of the present disclosure.

Claims

1. A method for preparing a patterned photoresist layer, characterized in that: Include: Coating a substrate with a photoresist solution, wherein the photoresist solution includes a photoresist and an additive; wherein the additive comprises at least one cyclic ether group, or at least one alkenyl or alkynyl group, or at least one phosphonic acid group or silane group, or at least one acrylate group, or at least one thiol group, or at least one amine group, or at least one isocyanate group, or at least one ureide group, or at least one anhydride group, or at least one halogenated acyl group, or at least one acyl ester group; or The additive is an alkoxy melamine or an aromatic alcohol or ether.

2. The method for preparing the patterned photoresist layer according to claim 1, wherein: The additive has a structure of formula (1-A) or formula (1-B): Where R 1 is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; Each R 2 is independently a hydrocarbon or a substituent containing a heteroatom; m is an integer from 0 to 12; Each L is -O-, -S-, a hydrocarbon, a substituted hydrocarbon, or a combination thereof; Each R a and R b are independently alkylene groups having 0 to 3 carbon atoms, but together have a minimum of 2 carbon atoms; Each R 3 are independently H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; and n is an integer from 1 to 20.

3. The method for preparing the patterned photoresist layer according to claim 1, wherein: The additive has a structure of formula (2-A) or formula (2-B): Where R 1 is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; Each R 2 is independently a hydrocarbon or a substituent containing a heteroatom; m is an integer from 0 to 12; Each L is -O-, -S-, a hydrocarbon, a substituted hydrocarbon, or a combination thereof; and n is an integer from 1 to 20.

4. The method for preparing the patterned photoresist layer according to claim 1, wherein: The additive has a structure of formula (3-A): wherein each R is independently H or And at least one R is Each R 1 are independently alkyl or; Each X is independently O or S; and Each R 2 is H, alkyl, aryl or a combination thereof.

5. The method for preparing the patterned photoresist layer according to claim 1, wherein: The additive has a structure of formula (4-A) or formula (4-B): wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; Each R 1 are independently hydrogen or alkyl; and n is an integer from 1 to 20.

6. The method for preparing the patterned photoresist layer according to claim 1, wherein: The additive has the structure of formula (5-A): Where R 1 Contains one or more aryl or heteroaryl groups which may be linked together via a covalent bond or an alkyl group; Each R 2 are independently alkyl, fluoroalkyl, aryl or a substituent containing a heteroatom; m is an integer from 0 to 12; Each L is a hydrocarbon, a substituted hydrocarbon, or a combination thereof; Each X is O or S; Each R 3 is hydrocarbon, substituted hydrocarbon, aryl or heteroaryl; and n is an integer from 1 to 20.

7. The method for preparing the patterned photoresist layer according to claim 1, wherein: The additive has a structure of formula (6-A): wherein R is H, hydrocarbon, substituted hydrocarbon, aryl or heteroaryl, or a combination thereof linked together via a covalent bond or an alkyl group; Each R 1 are independently hydrogen or alkyl; and n is an integer from 1 to 20.

8. The method for preparing the patterned photoresist layer according to claim 1, wherein: The additive has a structure of formula (7-A): R-(SH) n Formula (7-A) wherein R is a hydrocarbon, a substituted hydrocarbon, an aryl or a heteroaryl, or a combination thereof linked together by a covalent bond or an alkyl group; and n is an integer from 1 to 20.

9. A photoresist solution, characterized in that: Include: A metal photoresist and an additive; wherein the additive comprises at least one cyclic ether group, or at least one alkenyl or alkynyl group, or at least one phosphonic acid group or silane group, or at least one acrylate group, or at least one thiol group, or at least one amine group, or at least one isocyanate group, or at least one ureide group, or at least one anhydride group, or at least one halogenated acyl group, or at least one acyl ester group; or The additive is an alkoxy melamine or an aromatic alcohol or ether.

10. A method for preparing a patterned photoresist layer, characterized in that: Include: Coating a substrate with a photoresist solution; prebaking the coated substrate to cure the photoresist solution and form a photoresist layer; exposing the photoresist layer to radiation to pattern the photoresist layer; optionally performing a post-exposure bake of the coated substrate; and developing the patterned photoresist layer using a developer; wherein the photoresist solution or the developer comprises an additive; or wherein the coated substrate is treated with a treatment solution containing an additive during or after the coating, pre-bake, exposure, optional post-exposure bake, or development step; and wherein the additive comprises at least one cyclic ether group, or at least one alkenyl or alkynyl group, or at least one phosphonic acid group or silane group, or at least one acrylate group, or at least one thiol group, or at least one amine group, or at least one isocyanate group, or at least one ureide group, or at least one anhydride group, or at least one halogenated acyl group, or at least one acyl ester group; or The additive is an alkoxy melamine or an aromatic alcohol or ether.

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