Composition used for forming protective layer and method of manufacturing semiconductor device

Abstract

A method of manufacturing a semiconductor device includes the following operations: forming a protective layer over a substrate, wherein the protective layer is formed of a composition comprising a polymer having a polymer backbone and a plurality of end groups. The polymer backbone is formed by polymerizing a monomer composition comprising a plurality of first monomers, each of the first monomers independently having an aryl group substituted with 1, 2, 3, 4, or 5 hydroxyl groups. These end groups include: , , , , , , or combinations thereof. A is a substituted or unsubstituted hydrocarbon group. B is a hydroxyl, alkyl, or fluoroalkyl group. Forming a photoresist layer over the protective layer. Patterning the photoresist layer.

Description

Technical Field

[0001] none Prior Art

[0002] As consumer devices become increasingly smaller due to consumer demand, the size of the individual components within these devices must also decrease. Semiconductor devices, which form the primary components of devices such as mobile phones, tablets, and the like, are under pressure to become increasingly smaller, with corresponding pressure also being placed on the individual devices within these devices (e.g., transistors, resistors, capacitors, etc.) to shrink in size.

[0003] One enabling technique used in semiconductor device manufacturing processes is the use of photolithographic materials. These materials are applied to the surface of the layer to be patterned and then exposed to energy that has already been patterned. This exposure modifies the chemical and physical properties of the exposed areas of the photoresist material. This modification, combined with the lack of modification in unexposed areas of the photoresist material, can be used to remove one area without removing another.

[0004] However, as the size of individual devices decreases, the processes used for photolithography have become increasingly stringent. Therefore, advances in the field of photolithography are needed to better maintain the ability to scale down devices. Summary of the Invention

[0005] none Simple diagram description

[0006] The aspects of the present disclosure are best understood from the following detailed description when read in conjunction with the accompanying drawings. Please note that, in accordance with standard industry practice, various features are not drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or reduced for clarity of discussion. FIG. 1 illustrates a polymer used for a protective layer according to some embodiments. 2 to 5 are schematic diagrams illustrating cross-linked polymers and cross-linking agents according to some embodiments. FIG. 6 illustrates additives for a protective layer according to some embodiments. FIG. 7 is a top view of a semiconductor device according to some embodiments. FIG. 8 is a cross-sectional view taken along line AA of FIG. 7 , according to some embodiments. 9 to 18 are cross-sectional views of semiconductor devices during fabrication according to some embodiments. FIG. 19 is a cross-sectional view taken along line BB of FIG. 18 , according to some embodiments. Implementation Method

[0007] The following disclosure provides many different embodiments or examples for implementing various features of the provided subject matter. Specific examples of components and configurations are described below to simplify the disclosure. Of course, these components and configurations are merely examples and are not intended to be limiting. For example, in the following description, formation of a first feature over or on a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features such that the first and second features are not in direct contact. Furthermore, reference numbers and / or letters may be repeated throughout the disclosure in various examples. This repetition is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed.

[0008] The advanced lithography processes, methods, and materials described in the present disclosure can be used in many applications, including fin-type field-effect transistors (FinFETs). For example, fins can be patterned to create relatively tight spacing between features, a situation in which the above disclosure is particularly well-suited. Furthermore, spacers in fins used to form FinFETs can be processed according to the above disclosure.

[0009] The formation of integrated circuits may include multiple etching processes using etch masks to define the etch pattern. The etch mask can be either a double-layer mask comprising a bottom layer (e.g., an anti-reflective coating (BARC)) and a photoresist layer above the bottom layer, or a triple-layer mask comprising a bottom layer, a middle layer above the bottom layer, and a photoresist layer above the middle layer.

[0010] An etch mask can be used to pattern metal-containing layers. For example, to reduce gate leakage and enhance device performance, metal gate formation involves removing a dummy polysilicon gate, depositing a workfunction metal layer, forming an etch mask over the workfunction metal layer, and patterning the workfunction metal layer, for example, by wet etching. The workfunction metal layer can substantially conformally cover a substrate having a plurality of protrusions (e.g., fins) and a plurality of gaps. When forming the etch mask over the workfunction metal layer, the bottom layer of the etch mask (e.g., a BARC) should fill the gaps to protect the workfunction metal layer. However, the gap-filling capability of the bottom layer decreases in small gaps (having a gap width of less than or equal to 10 nm). If the bottom layer does not have high gap-filling capability, high wet etch resistance, and good adhesion to the metal layer, portions of the workfunction metal layer may not be protected by the bottom layer, resulting in damage or defects in the workfunction metal layer during wet etching. The bottom layer is formed by crosslinking a polymer. Gap-filling capability and wet etch resistance are affected by the molecular weight of the polymer. For gaps with a gap width of approximately 10 nm or less, if the polymer has a low molecular weight (e.g., 100 to 4000), the bottom layer may have high gap-filling capability but low wet etch resistance because the bottom layer includes smaller polymer grains. In contrast, if the polymer has a high molecular weight (e.g., >4000), the bottom layer may have high wet etch resistance but low gap-filling capability because the bottom layer includes larger polymer grains. Therefore, the design of the polymer used to form the bottom layer should overcome these issues and be appropriate for the bottom layer.

[0011] The present disclosure provides a composition for forming a protective layer for a bottom layer (e.g., a BARC) that can be used as an etch mask, and a method for manufacturing a semiconductor device using the protective layer. The protective layer has high gap filling capability, high wet etch resistance, and good adhesion to metal-containing layers such as work function metal layers.

[0012] The composition of the present disclosure includes one or more cross-linkable polymers. FIG1 illustrates a polymer used in a protective layer according to some embodiments. As shown in FIG1 , polymer P1 includes a repeating unit RU1. Polymer P2 includes a repeating unit RU1, an end unit EU1, and an end unit EU2. End unit EU1 has an end group EG1, and end unit EU2 has an end group EG2. Polymer P2 includes a polymer backbone (or polymer chain) and end groups EG1 and EG2 bonded to the polymer backbone. Polymer P3 includes a repeating unit RU1 and a repeating unit RU2. Repeating unit RU2 has a functional group FG1. Polymer P3 includes a polymer backbone substituted with one or more functional groups FG1. Polymer P4 includes a repeating unit RU1, a repeating unit RU2, an end unit EU1, and an end unit EU2. End unit EU1 has an end group EG1, and end unit EU2 has an end group EG2. Polymer P4 includes a polymer backbone and end groups EG1 and EG2 bonded to the polymer backbone. Polymer P4 comprises a polymer backbone substituted with one or more functional groups FG1. A unit may also be referred to as a monomer unit. Polymers P3 and P4 are random copolymers, and the arrangement of repeating units RU1 and RU2 shown in FIG. 1 is for illustrative purposes only and does not limit the present disclosure. In some embodiments, polymers P3 and P4, respectively, comprise 20 to 95 mol% of repeating units RU1 and 5 to 80 mol% of repeating units RU2.

[0013] Note that the terminal unit EU1 has an end group EG1, the terminal unit EU2 has an end group EG2, and each of the repeating units RU2 has a functional group FG1. The end groups EG1 and EG2, as well as the functional group FG1, each comprise a crosslinkable group, such as an alkenyl or alkynyl group, which enhances crosslinking between the polymers. The structures of the end groups EG1, EG2, and the functional group FG1 will be described further below. In some embodiments, polymers P1, P2, P3, and P4 each comprise a repeating unit RU1 having a different structure. In some embodiments, polymers P3 and P4 each comprise a repeating unit RU2 having a different structure.

[0014] In some embodiments, the polymer backbones of polymers P1, P2, P3, and P4 independently formed by polymerizing a monomer composition comprising monomers have aromatic groups (e.g., benzene rings) substituted with 1, 2, 3, 4, or 5 hydroxyl groups. In some embodiments, the monomers independently have hydroxyphenyl, dihydroxyphenyl, trihydroxyphenyl, tetrahydroxyphenyl, or pentahydroxyphenyl groups. In some embodiments, the monomers independently have crosslinkable groups, such as alkenyl groups. In some embodiments, polymers P1, P2, P3, and P4 are independently novolac polymers, substituted poly(hydroxystyrene) (PHS), unsubstituted poly(hydroxystyrene), acrylate polymers, or substituted polyethylene, and the substituted poly(hydroxystyrene) and substituted polyethylene are each substituted with one or more functional groups, such as hydroxyphenyl, dihydroxyphenyl, trihydroxyphenyl, tetrahydroxyphenyl, pentahydroxyphenyl, or a combination thereof. For example, the functional groups include 、 、 、 、 、 or a combination thereof.

[0015] In some embodiments, the repeating unit RU1 is formed from monomers used to form the following: novolac polymers, substituted poly(hydroxystyrene), unsubstituted poly(hydroxystyrene), acrylate polymers, substituted polyethylene, or combinations thereof. Substituted poly(hydroxystyrene) and substituted polyethylene are each substituted with hydroxyphenyl, dihydroxyphenyl, trihydroxyphenyl, tetrahydroxyphenyl, pentahydroxyphenyl, or combinations thereof. In some embodiments, monomers used to form the repeating unit RU1 include, but are not limited to, 、 、 、 、 、 、 、 、 , catechol, resorcinol, hydroquinone, pyrogallol, pyrogallol, 1,2,3,4-tetrahydroxybenzene, 1,2,3,5-tetrahydroxybenzene, 1,2,4,5-tetrahydroxybenzene, 、 or combinations thereof. R1 and R2 are independently hydroxyphenyl, dihydroxyphenyl, trihydroxyphenyl, tetrahydroxyphenyl, or pentahydroxyphenyl. In some embodiments, the novolac polymer can be prepared by condensing formaldehyde with the above-mentioned monomers used to form the novolac polymer, such as phenol, m-cresol, or p-cresol. In some embodiments, the polymer backbone of polymer P1, P2, P3, or P4 has repeating units RU1 comprising: 、 、 、 、 、 、 、 、 、 、 、 、 、 、 or a combination thereof. R 1 and R 2 are independently hydroxyphenyl, dihydroxyphenyl, trihydroxyphenyl, tetrahydroxyphenyl, or pentahydroxyphenyl. In this disclosure, * indicates a bonding position.

[0016] Still referring to FIG. 1 , the terminal unit EU1 has an end group EG1, the terminal unit EU2 has an end group EG2, and the repeating unit RU2 has a functional group FG1. The end groups EG1 and EG2 or the functional group FG1 include 、 、 、 、 、 、 or a combination thereof. A is a substituted or unsubstituted hydrocarbon group, and B is a hydroxyl group, an alkyl group, or a fluoroalkyl group. In some embodiments, the end groups EG1 and EG2 and the functional group FG1 are the same or different. In some embodiments, polymer P3 or polymer P4 includes different functional groups FG1. The end groups EG1, EG2, and functional group FG1 each include an alkenyl group or an alkynyl group, which can enhance crosslinking between the polymers. Alkynyl groups can be more reactive than alkenyl groups. In some embodiments, A is a substituted hydrocarbon group substituted with a hydroxyl group, an ester group, a halogen group, or a combination thereof. In some embodiments, A is a branched or unbranched, cyclic or acyclic, or saturated or unsaturated hydrocarbon group. In some embodiments, A is a saturated hydrocarbon group, an aromatic hydrocarbon group (e.g., a benzene ring), or an aromatic hydrocarbon group (e.g., a benzene ring) substituted with 1, 2, 3, or 4 hydroxyl groups. In some embodiments, A has a carbon number between 1 and 6, such as 1, 2, 3, 4, 5, or 6. In some embodiments, the saturated hydrocarbon group has a carbon number between 1 and 6, such as 1, 2, 3, 4, 5, or 6. Furthermore, when A includes an aromatic hydrocarbon group (e.g., a benzene ring), the reactivity of the alkenyl and alkynyl groups can be enhanced. In some embodiments, B is an alkyl group having a carbon number between 1 and 6, such as 1, 2, 3, 4, 5, or 6. In some embodiments, B is a fluoroalkyl group having the structure -(CH2)nCFx, where n is 1 to 4 and x is 1 to 2.

[0017] In some embodiments, end unit EU1 or end unit EU2 is formed from a monomer having an aromatic group substituted with 1, 2, 3, 4, or 5 hydroxyl groups, and the monomer is substituted with terminal group EG1 or terminal group EG2. In some embodiments, the monomer is used to form a novolac polymer, a substituted poly(hydroxystyrene), an unsubstituted poly(hydroxystyrene), an acrylate polymer, a substituted polyethylene, or a combination thereof, and the monomer is substituted with terminal group EG1 or terminal group EG2. In some embodiments, repeating unit RU2 is formed from a monomer independently having an aromatic group substituted with 1, 2, 3, 4, or 5 hydroxyl groups, and the monomer is each substituted with functional group FG1. In some embodiments, the monomer is used to form a novolac polymer, a substituted poly(hydroxystyrene), an unsubstituted poly(hydroxystyrene), an acrylate polymer, a substituted polyethylene, or a combination thereof, and the monomer is each substituted with functional group FG1.

[0018] In some embodiments, monomers used to form the end unit EU1, the end unit EU2, and the repeating unit RU2 include, but are not limited to, the following: 、 、 、 、 、 、 、 、 , catechol, resorcinol, hydroquinone, pyrogallol, pyrogallol, 1,2,3,4-tetrahydroxybenzene, 1,2,3,5-tetrahydroxybenzene, 1,2,4,5-tetrahydroxybenzene, 、 or a combination thereof, and the monomer is substituted with one or more functional groups such as terminal group EG1, terminal group EG2 or functional group FG1. R1 and R2 are independently hydroxyphenyl, dihydroxyphenyl, trihydroxyphenyl, tetrahydroxyphenyl or pentahydroxyphenyl. In some embodiments, the terminal unit EU1, the terminal unit EU2 and the repeating unit RU2 respectively include 、 、 、 、 、 、 、 、 、 、 、 、 、 、 or a combination thereof. R1 and R2 are independently hydroxyphenyl, dihydroxyphenyl, trihydroxyphenyl, tetrahydroxyphenyl, or pentahydroxyphenyl, and the terminal unit EU1, the terminal unit EU2, and the repeating unit RU2 are substituted with one or more functional groups, such as the terminal group EG1, the terminal group EG2, or the functional group FG1.

[0019] In some embodiments, for 、 or , and n is 1 to 2.

[0020] In some embodiments, for 、 、 、 、 or , such as or .

[0021] In some embodiments, for 、 or , and n is 1 to 2.

[0022] In some embodiments, for 、 、 、 、 or , such as .

[0023] In some embodiments, for 、 、 、 、 or .

[0024] In some embodiments, for 、 ,or , and n is 1 to 2.

[0025] In some embodiments, for 、 、 、 、 or , such as .

[0026] Still referring to FIG. 1 , in some embodiments, the composition used to form the protective layer includes polymer P2, polymer P3, polymer P4, or a combination thereof. More specifically, the composition may include polymer P2, polymer P3, polymer P4, polymers P2 and P3, polymers P2 and P4, polymers P3 and P4, or polymers P2, P3, and P4. In some embodiments, the composition further includes polymer P1. In some embodiments, polymer P1, polymer P2, polymer P3, and polymer P4 each have a weight-average molecular weight between greater than 1,000 Daltons and 10,000 Daltons, such as 1,100, 1,500, 2,000, 3,000, 4,000, 5,000, 6,000, 7,000, 8,000, 9,000, or 10,000 Daltons.

[0027] In some embodiments, the composition for forming the protective layer includes a polymer having a polymer backbone and terminal units, wherein the polymer backbone and the terminal units are independently unsubstituted or composed of 、 、 、 、 、 or a combination thereof. A is a substituted or unsubstituted hydrocarbon group. B is a hydroxyl group, an alkyl group, or a fluoroalkyl group. The polymer backbone, the terminal units, or a combination thereof are substituted. If the polymer backbone is substituted, the polymer is polymer P3. If the terminal units are substituted, the polymer is polymer P2. If the polymer backbone and the terminal units are substituted, the polymer is polymer P4.

[0028] In some embodiments, the composition includes one or more polymers for forming a protective layer, a crosslinker, and a solvent. In other embodiments, the composition includes one or more polymers for forming a protective layer and a solvent, and the composition lacks a crosslinker because the polymers have crosslinkable groups such as end groups EG1, end groups EG2, functional groups FG1, or a combination thereof. In some embodiments, the composition further includes an initiator. In some embodiments, a baking process may be performed to induce a crosslinking reaction and enhance the degree of crosslinking of the components in the composition. In other words, the baking process may promote the crosslinking reactions depicted in Figures 2 through 5. In some embodiments, the baking temperature is between 180°C and 300°C, such as 180, 200, 220, 240, 260, 280, or 300°C. If the baking temperature exceeds 300°C, the polymer may degrade. In some embodiments, the composition further includes a surfactant.

[0029] In some embodiments, the crosslinker has one or more epoxy groups. In some embodiments, the crosslinker can be formed from monomers used to form a novolac polymer, a substituted poly(hydroxystyrene), an unsubstituted poly(hydroxystyrene), an acrylate polymer, a substituted polyethylene, or a combination thereof, and the crosslinker is substituted with one or more epoxy groups that react with the hydroxyl groups in the polymer. The structure and formation method of the crosslinker are described in the examples of polymer P1. The crosslinker differs from polymer P1 in that the crosslinker is substituted with one or more epoxy groups. In some embodiments, the crosslinker has a weight-average molecular weight between 100 Daltons and 10,000 Daltons, such as 100, 500, 1,000, 2,000, 3,000, 4,000, 5,000, 6,000, 7,000, 8,000, 9,000, or 10,000 Daltons.

[0030] In some embodiments, the solvent includes 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, 4-methyl-2-pentanol, acetone, methyl ethyl ketone, dimethylformamide (DMF), isopropanol (IPA), tetrahydrofuran (THF), methyl isobutyl carbinol (MIBC), n-butyl acetate (nBA), 2-heptanone (MAK), a dioxane, or a combination thereof. In some embodiments, the initiator is a thermal free radical initiator, a photo free radical initiator, or a combination thereof.In some embodiments, the thermal free radical initiator is selected from one or more of the group consisting of azobisisobutyronitrile (AIBN), 2,2′-azobis(2-methylbutyronitrile) (AMBN), 2,2′-azobis(2,4-dimethyl)valeronitrile (ADVN), 4,4′-azobis(4-cyanopentanoic acid) (ACVA), dimethyl 2,2′-azobis(2-methylpropanoic acid), 2,2′-azobis(2-(2-imidazolin-2-yl)propane) dihydrochloride (2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH), 2,2′-azo[2-(2-imidazolin-2-yl)propane] dihydrochloride, tert-butyl-hydroperoxide (TBHP), cumene hydroperoxide, di(tertiary-butyl)peroxide, diisopropyl peroxide, benzoyl peroxide (BPO), dicyandiamide, cyclohexyl tosylate, methyldiphenylsulfonium tetrafluoroborate, benzyl(4-hydroxyphenyl)methylsulfonium hexafluoroantimonate, and (4-hydroxyphenyl)methyl-(2-methylbenzyl)sulfonium hexafluoroantimonate. In some embodiments, the photoradical initiator is selected from one or more of the group consisting of camphorquinone, acetophenone, 3-hydroxyacetophenone, 4-hydroxyacetophenone, benzophenone, 2-methylbenzophenone, 3-methylbenzophenone, 3-hydroxybenzophenone, 3,4-dimethylbenzophenone, 4-hydroxybenzophenone, 4-benzoylbenzoic acid, 2-benzoylbenzoic acid, methyl 2-benzoylbenzoate, 4,4'-dihydroxybenzophenone, 4-(dimethylamino)-benzophenone, 4,4'-bis(dimethylamino)benzophenone, benzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-dichlorobenzophenone, 4-(p-oxy)benzophenone, 4-phenylbenzophenone, 1,4-diphenylmethane, benzil, 4,4'-dimethyldiphenylmethane, 4,4'-dimethoxyphenol ester, 2-benzoyl-2-propanol, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, 1-hydroxycyclohexylphenyl ketone, benzoyl alcohol and anisoin.

[0031] Please refer to Figures 1 to 5. Figures 2 to 5 illustrate schematic diagrams of cross-linked polymers and cross-linkers according to some embodiments. As shown in Figure 2, polymer P1 and cross-linker CL are cross-linked by reacting groups G1 (e.g., hydroxyl groups) of polymer P1 with groups G2 (e.g., epoxy groups) of cross-linker CL. As shown in Figure 3, polymer P2 and cross-linker CL are cross-linked by reacting groups G1 (e.g., hydroxyl groups) of polymer P2 with groups G2 (e.g., epoxy groups) of cross-linker CL. Furthermore, polymer P2 can also be bonded to each other by reacting end groups EG1 and EG2 (including alkenyl groups, alkynyl groups, or a combination) of polymer P2. Consequently, polymer P2 and cross-linker CL can form larger crystals than those formed by polymer P1 and cross-linker CL. Furthermore, the bonds formed by groups G1 and G2 can be –COC–, and bond cleavage can readily occur in the presence of a wet etchant. The bonds formed by the end groups EG1 and EG2 can be –C-C– or –C=C–, both of which have higher wet etch resistance than –C-O-C–. Therefore, polymer P2 has greater wet etch resistance than polymer P1 due to its larger particle size, –C-C–, and / or –C=C–. As shown in Figure 4, polymer P3 and crosslinker CL are crosslinked by reacting groups G1 (e.g., hydroxyl groups) in polymer P3 with groups G2 (e.g., epoxy groups) in crosslinker CL. Furthermore, polymer P3 can be bonded to each other by reacting functional groups FG1 (including alkenyl groups, alkynyl groups, or a combination) in polymer P3. In other words, the crystallites formed by polymer P3 and crosslinker CL can be further bonded to each other by reacting functional groups FG1. Figure 4 illustrates grain boundaries GB1. Therefore, polymer P3 and crosslinker CL can form crystallites that are larger than those formed by polymer P1 and crosslinker CL. Furthermore, the bond formed by groups G1 and G2 can be –COC–, and the bond formed by functional group FG1 can be –CC– or –C═C–, both of which have higher wet etch resistance than –COC–. Therefore, polymer P3 has higher wet etch resistance than polymer P1 due to larger grains, –CC–, and / or –C═C–. As shown in Figure 5, polymer P4 and crosslinker CL are crosslinked by reacting groups G1 (e.g., hydroxyl groups) of polymer P4 with groups G2 (e.g., epoxy groups) of crosslinker CL. Furthermore, polymers P4 can also be bonded to each other by reacting terminal groups EG1 and EG2 (including alkenyl groups, alkynyl groups, or a combination) of polymer P4. Furthermore, polymers P4 can also be bonded to each other by reacting functional groups FG1 (including alkenyl groups, alkynyl groups, or a combination) of polymer P4. In other words, the crystallites formed by the polymer P4 and the crosslinker CL can be further bonded to each other by reacting the functional groups FG1. FIG5 shows the grain boundary GB2.Polymer P4 has a wet etch resistance greater than that of polymer P1, polymer P2, or polymer P3 due to larger grains, -CC-, and / or -C=C-.

[0032] In some embodiments, the composition for forming the protective layer further includes an oligomer to enhance the gap filling ability of the composition. Oligomers are more likely to flow into small gaps due to their smaller size. Subsequently, the oligomer can be cross-linked with the polymer. The oligomer has an oligomer backbone and terminal units and has a weight average molecular weight between 500 Daltons and 1000 Daltons, such as 500, 600, 700, 800, 900 or 1000 Daltons. Please refer to the examples of polymers for the structure and formation method of the oligomer. The difference between an oligomer and a polymer is the weight average molecular weight. For example, the oligomer backbone and terminal units are independently unsubstituted or are replaced by the inclusion of 、 、 、 、 、 or a combination thereof. The oligomer backbone, terminal units, or a combination thereof are substituted. For examples of A and B, please refer to the previously mentioned examples, and their detailed descriptions will not be repeated here.

[0033] In some embodiments, the composition used to form the protective layer further includes one or more additives to enhance the gap-filling capability of the composition. Due to their smaller size, the additives are more easily able to flow into small gaps. Subsequently, the oligomer can be cross-linked with the polymer and / or oligomer. FIG6 illustrates an additive AD having a functional group FG2 for use in the protective layer according to some embodiments. Examples of functional group FG2 refer to the examples of functional group FG1. In other words, functional group FG2 is the same as functional group FG1. Examples of monomers used to form additive AD refer to the examples of monomers used to form repeating unit RU2. In some embodiments, the additive includes a plurality of monomers each independently having an aromatic group (e.g., a benzene ring) substituted with one, two, three, four, or five hydroxyl groups, and the monomers are substituted with functional group FG2. In some embodiments, the additive is a monomer used to form a novolac polymer, a substituted poly(hydroxystyrene), an unsubstituted poly(hydroxystyrene), an acrylate polymer, a substituted polyethylene, or a combination thereof. The substituted poly(hydroxystyrene) and substituted polyethylene are each substituted with a hydroxyphenyl group, a dihydroxyphenyl group, a trihydroxyphenyl group, a tetrahydroxyphenyl group, a pentahydroxyphenyl group, or a combination thereof, and the monomer is substituted with a functional group FG2. In some embodiments, the additive has a weight average molecular weight between 50 Daltons and less than 500 Daltons, such as 50, 100, 200, 300, 400, or 450 Daltons.

[0034] In some embodiments, the composition includes additives having different structures. In some embodiments, the composition includes one or more additives including: 、 、 、 、 、 、 、 、 , catechol, resorcinol, hydroquinone, pyrogallol, pyrogallol, 1,2,3,4-tetrahydroxybenzene, 1,2,3,5-tetrahydroxybenzene, 1,2,4,5-tetrahydroxybenzene, 、 、 、 、 or a combination thereof, R 1 and R 2 are independently hydroxyphenyl, dihydroxyphenyl, trihydroxyphenyl, tetrahydroxyphenyl or pentahydroxyphenyl, and the additive is substituted by one or more functional groups including: 、 、 、 、 、 or a combination thereof. A is a substituted or unsubstituted hydrocarbon group, and B is a hydroxyl group, an alkyl group, or a fluoroalkyl group. For examples of A and B, please refer to the previously mentioned examples, and their detailed description will not be repeated here.

[0035] Next, the present disclosure provides a method for manufacturing a semiconductor device. FIG. 7 is a top view of a semiconductor device according to some embodiments. FIG. 8 is a cross-sectional view taken along line AA of FIG. 7 according to some embodiments. FIG. 9 through FIG. 18 are cross-sectional views of a semiconductor device during fabrication according to some embodiments.

[0036] During the fabrication of fin field effect transistor (FinFET) devices, a gate replacement process can be performed to adjust the threshold voltage (Vt) associated with the fabrication steps. For example, during a "gate-last" process, a dummy gate structure is first formed above the substrate as a locator before forming other components, such as source / drain features. Once the other components have been formed, the dummy gate structure is removed and a metal gate structure is formed in its place. Multiple patterning processes can be performed to form various material layers within the metal gate structure to provide certain device capabilities, such as multiple threshold voltages. Multiple threshold voltage (Vt) devices enable flexible and diverse applications for FinFETs.

[0037] Multiple threshold voltages for FinFET devices have been achieved by stacking multiple work function metal (WFM) layers within the metal gate structure. In one example, a thicker WFM stack yields a higher work function and a higher threshold voltage (Vt). However, as device feature sizes decrease, numerous challenges arise when stacking WFM layers. For example, due to the decreasing fin-to-fin spacing, when an etch mask is formed over the work function metal layer, the mask may not easily fill the gaps between the fins to protect the work function metal layer.

[0038] As shown in Figures 7 and 8, semiconductor device 200 may be an intermediate device (or IC structure) fabricated during the processing of an IC. The IC may include static random-access memory (SRAM) and / or other logic circuits; passive components such as resistors, capacitors, and inductors; and active components such as p-type FETs (PFETs), n-type FETs (NFETs), FinFETs, metal-oxide semiconductor field-effect transistors (MOSFETs), complementary metal-oxide semiconductor (CMOS) transistors, bipolar transistors, high-voltage transistors, high-frequency transistors, and / or other memory cells. The present disclosure is not limited to any specific number of devices or device regions, or any specific device configuration. For example, although semiconductor device 200 is shown as a three-dimensional FinFET device, the present disclosure also provides embodiments for fabricating planar FET devices.

[0039] A semiconductor device 200 is provided. The semiconductor device 200 includes a substrate 202 having a first region 203 and a second region 205, an isolation structure 208 formed above the substrate 202 to separate the various components of the semiconductor device 200, a gate spacer 212, and an interlayer dielectric (ILD) layer 218 formed above the isolation structure 208. In some embodiments, the first region 203 includes two fins, namely, fin 207a and fin 207b, and the second region 205 also includes two fins, namely, fin 207c and fin 207d. The fins 207a-207d may include FET features, such as channel regions 230a, 230b, 230c, and 230d, respectively. As shown in FIG. 7 , source / drain regions 70 are formed on each of the fins 207a-207d and separated by the channel regions 230a-230d. As depicted in FIG. 8 , the fins 207 a - 207 d are aligned from right to left, but the present disclosure works with any order of the fins 207 a - 207 d , and the fins may or may not be directly adjacent to each other.

[0040] Continuing with Figures 7 and 8 , gate trenches 220 and 222 are formed to expose the channel regions 230a to 230d of the fins 207a to 207d. As shown in Figure 8 , the gate spacers 212 and the ILD layer 218 define two gate trenches 220 and 222 that are not filled with metal material. From the top view in Figure 7 , the fins 207a to 207d are generally covered by the ILD layer 218, but the gate trenches 220 and 222 each expose a respective set of channel regions 230a to 230d. For simplicity, the method operations are described with respect to the gate trench 220 (but not the gate trench 222, as they undergo the same manufacturing process).

[0041] In some embodiments, the gate trench 220 is formed by removing the dummy gate structure on the fins 207a to 207d, thereby exposing the channel regions 230a to 230d of the fins 207a to 207d. The dummy gate structure may include one or more material layers, such as an oxide layer (i.e., a dummy gate dielectric layer), a polysilicon layer (i.e., a dummy gate electrode), a hard mask layer, a cap layer, and / or other suitable layers. In some embodiments, forming the gate trench 220 includes an etching process that selectively removes the dummy gate structure using a dry etching process, a wet etching process, other suitable methods, or a combination thereof. The dry etching process may use a chlorine-containing gas, a fluorine-containing gas, and / or other etching gases. The wet etching solution may include ammonium hydroxide (NH4OH), hydrofluoric acid (HF) or diluted HF, deionized water, tetramethylammonium hydroxide (TMAH), and / or other suitable wet etching solutions.

[0042] As shown in Figures 7 and 8, substrate 202 may include elemental (single-element) semiconductors such as silicon, germanium, and / or other suitable materials; compound semiconductors such as silicon carbide, gallium arsenide, gallium phosphide, indium phosphide, indium arsenide, indium antimonide, and / or other suitable materials; or alloy semiconductors such as SiGe, GaAsP, AlInAs, AlGaAs, GaInAs, GaInP, GaInAsP, and / or other suitable materials. Substrate 202 may be a single layer of material having a uniform composition. Alternatively, substrate 202 may include multiple layers of material having similar or different compositions suitable for IC device fabrication. In some embodiments, substrate 202 may be a silicon-on-insulator (SOI) substrate having a silicon layer formed on a silicon oxide layer. In some other embodiments, substrate 202 may include a conductive layer, a semiconductor layer, a dielectric layer, other layers, or combinations thereof.

[0043] In some embodiments, substrate 202 includes FETs and various doped regions, such as source / drain regions, formed in or on substrate 202. Depending on design specifications, the doped regions may be doped with p-type dopants, such as phosphorus or arsenic, and / or n-type dopants, such as boron or BF2. The doped regions may be formed directly on substrate 202, in a p-type well structure, an n-type well structure, a dual well structure, or using a riser structure. The doped regions may be formed by implantation of dopant atoms, in-situ doping epitaxial growth, and / or other suitable techniques.

[0044] First region 203 may be suitable for forming one or more n-type FinFETs, and second region 205 may be suitable for forming one or more p-type FinFETs. Thus, channel regions 230a and 230b located on fins 207a and 207b are n-type channels, and channel regions 230c and 230d located on fins 207c and 207d are p-type channels. In alternative embodiments, first region 203 and second region 205 may be suitable for forming similar types of FinFETs with different threshold voltage (Vt) design specifications, either both n-type or both p-type. This configuration in Figures 7 and 8 is for illustrative purposes only and does not limit the present disclosure. Fins 207a to 207d may be fabricated using a suitable process including photolithography and etching. The photolithography process may include forming a photoresist layer (resist) overlying substrate 202, exposing the resist to a pattern, performing a post-exposure bake process, and developing the resist to form a masking element (not shown) comprising the resist. The masking element is then used to etch recesses into substrate 202, leaving fins 207a to 207d on substrate 202. The etching process may include dry etching, wet etching, reactive ion etching (RIE), and / or other suitable processes.

[0045] Other methods for forming fins 207a-207d may be applicable. For example, fins 207a-207d may be patterned using a double patterning or multi-patterning process. Generally, a double patterning or multi-patterning process combines optical lithography with a self-aligned process, thereby allowing patterns to be produced that have, for example, a spacing smaller than would otherwise be achieved using a single direct optical lithography process. For example, in some embodiments, a sacrificial layer is formed over a substrate and patterned using an optical lithography process. Spacers are formed along the patterned sacrificial layer using a self-aligned process. The sacrificial layer is then removed, and the remaining spacers or mandrels can then be used to pattern the fins.

[0046] Isolation structure 208 may include silicon oxide, silicon nitride, silicon oxynitride, fluoride-doped silicate glass (FSG), low-k dielectric material, and / or other suitable materials. Isolation structure 208 may include shallow trench isolation (STI) features. In some embodiments, isolation structure 208 is formed by etching trenches in substrate 202 during the formation of fins 207 a - 207 c. The trenches may then be filled with the aforementioned isolation material, followed by a chemical mechanical planarization (CMP) process. Other isolation structures such as field oxide, local oxidation of silicon (LOCOS), and / or other suitable structures may also be implemented as isolation structure 208. Alternatively, isolation structure 208 may include a multi-layer structure, for example, with one or more thermal oxide liner layers.

[0047] Gate spacers 212 are formed on the sidewalls of gate trenches 220. Gate spacers 212 may include a dielectric material such as silicon oxide, silicon nitride, silicon carbide, silicon oxynitride, and / or other suitable dielectric materials. Gate spacers 212 may be a single-layer structure or a multi-layer structure. In some embodiments, ILD layer 218 includes a dielectric material such as tetraethylorthosilicate (TEOS); undoped silicate glass or doped silicon oxide such as borophosphosilicate glass (BPSG), fused silica glass (FSG), phosphosilicate glass (PSG), boron doped silicon glass (BSG); and / or other suitable dielectric materials. ILD layer 218 may include a multi-layer structure comprising multiple dielectric materials.

[0048] See FIG. 9 . An interfacial layer (IL) 302 is formed over the fins 207 a - 207 d and in the gate trench 220 . The IL 302 may include a dielectric material such as silicon oxide or silicon oxynitride (SiON). The IL 302 may be formed to any suitable thickness, such as approximately 0.5 nm to approximately 1.5 nm. The interface layer 302 may be formed by any suitable deposition technique, such as chemical oxidation, thermal oxidation, atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), low-pressure chemical vapor deposition (LP-CVD), plasma-enhanced CVD (PE-CVD), high-density plasma CVD (HDP-CVD), metal organic CVD (MO-CVD), remote plasma CVD (RP-CVD), atomic layer CVD (AL-CVD), atmospheric pressure CVD (AP-CVD), and / or other suitable methods.

[0049] See FIG. 10 . A high-k dielectric layer 304 is formed over the interface layer 302 and within the gate trench 220 . In this disclosure, "high-k" dielectrics generally refer to one or more materials having a dielectric constant greater than that of silicon dioxide (SiO 2 ). High-k dielectric layer 304 can be formed to any suitable thickness by ALD and / or other suitable methods. In one embodiment, high-k dielectric layer 304 has a thickness of approximately 1 nm to approximately 2 nm. In some other embodiments, high-k dielectric layer 304 can be formed over an intermediate material layer such that high-k dielectric layer 304 does not directly contact interface layer 302 . In some embodiments, high-k dielectric layer 304 comprises an oxide based on hafnium, zirconium, silicon, and / or other suitable materials. For example, high-k dielectric layer 304 may include hafnium oxide (HfO 2 ), hafnium oxysilicon dioxide, and / or hafnium zirconium oxide. Since both the high-k dielectric layer 304 and the interface layer 302 are dielectric layers used in the gate structure, the two are collectively referred to as the gate dielectric layer 305. [ , , ]

[0050] After forming the gate dielectric layer 305, a work function metal (WFM) layer is formed on the gate dielectric layer 305 to provide a work function to adjust the threshold voltage of the subsequent transistor. Each fin can be used to implement a FinFET having a source, drain, channel, and gate. The threshold voltage of a fin refers to the minimum gate-to-source voltage required to create a conductive path in the channel between the source and drain. The source / drain region may refer to the source or drain individually or collectively, depending on the context. The threshold voltage is influenced by various parameters, including the work function of the gate. As device feature sizes decrease, implementing thick WFM structures presents numerous challenges during lithography and patterning processes.

[0051] See FIG. 11 . A p-type WFM layer 308 is formed in the gate trench 220 and over the high-k dielectric layer 304. In some embodiments, the p-type WFM layer 308 substantially conformally covers the gate dielectric layer 305. In other words, the p-type WFM layer 308 substantially conformally covers the substrate including the substrate 202, the isolation structure 208, and the gate dielectric layer 305, and the substrate has a plurality of protrusions and a plurality of gaps as shown in FIG. 11 . The p-type WFM layer 308 may include a metal having a sufficiently large effective work function selected from, but not limited to, the following: titanium nitride (TiN), tantalum nitride (TaN), ruthenium (Ru), molybdenum (Mo), tungsten (W), platinum (Pt), tungsten carbide nitride (WCN), titanium aluminum nitride (TiAlN), or combinations thereof. The p-type WFM layer 308 may be formed by a deposition process such as ALD, CVD, PVD, and / or other suitable processes. Therefore, depending on the desired work function on fins 207c and 207d, p-type WFM layer 308 can have any suitable thickness, such as about 1 nm to about 2 nm. In some embodiments, for patterning efficiency, p-type WFM layer 308 is less than 1.5 nm thick. Furthermore, as shown in FIG. 11 , in some embodiments, p-type WFM layer 308 is in contact with high-k dielectric layer 304 without any intervening layers, such as a barrier layer or a high-k cap layer (e.g., silicon nitride).

[0052] See FIG. 12 . As shown in FIG. 12 , an etch mask EM comprising a protective layer 402 (e.g., a bottom anti-reflective coating), an optional intermediate layer 403, and a photoresist layer 404 is formed in the gate trench 220 and on the ILD layer 218. The etch mask EM is formed over the substrate 202. Note that the substrate 202 has a plurality of protrusions (i.e., fins 207 a to 207 d) and a plurality of gaps G, and the protective layer 402 fills the gaps G. In some embodiments, the gaps G between adjacent fins have a gap width W less than or equal to approximately 10 nm, approximately 8 nm, approximately 6 nm, approximately 4 nm, or approximately 2 nm, respectively. In some embodiments, after forming or filling the protective layer 402 or the composition used to form the protective layer 402 in the gaps G, a baking process is performed to enhance the crosslinking of the protective layer 402. In some embodiments, the baking temperature is between 180°C and 300°C, such as 180, 200, 220, 240, 260, 280, or 300°C. If the baking temperature exceeds 300°C, the polymer may degrade. In some embodiments, aromatic groups substituted with one, two, three, four, or five hydroxyl groups in the polymer can enhance adhesion of the protective layer 402 to the p-type WFM layer 308. Furthermore, these aromatic groups can also enhance adhesion of the protective layer 402 to the n-type WFM layer. In some other embodiments, an etch mask EM can be used to pattern other components in a gate-all-around (GAA) FET, such as the WFM layer.

[0053] In some embodiments, protective layer 402 is formed from a composition of any of the previously mentioned embodiments. For example, the composition includes polymer P2, polymer P3, polymer P4, or a combination thereof. In some embodiments, any of the polymers used to form the protective layer and any of the compositions of the previously mentioned embodiments can be used to form protective layer 402. Because protective layer 402 or the composition used to form protective layer 402 has high gap-filling capability, gap G can be filled with protective layer 402 without voids. In some embodiments, optional intermediate layer 403 includes an inorganic material such as a nitride (e.g., silicon nitride), an oxynitride (e.g., silicon oxynitride), an oxide (e.g., silicon oxide), or a combination thereof. In some embodiments, photoresist layer 404 includes an organic material such as diazonaphthoquinone, novolac resin, bisphenol A novolac epoxy resin, off-stoichiometric thiol-ene (OSTE) polymer, or a combination thereof. In some embodiments, protective layer 402 is formed by a spin-coating process. In some embodiments, the optional intermediate layer 403 and the photoresist layer 404 are blanket deposited using, for example, a spin-on process, CVD, ALD, PVD, or a combination thereof.

[0054] Please refer to Figure 13. The photoresist layer 404 is patterned to expose the optional intermediate layer 403 by a photolithography process, which includes exposing, performing a post-exposure bake process, and developing the photoresist layer 404.

[0055] See FIG. 14 . The protective layer 402 and optional intermediate layer 403 are patterned using the photoresist layer 404 as an etching mask. Patterning is performed by dry etching and / or other suitable processes. For example, dry etching can utilize nitrogen-containing etchant gases (e.g., N₂), hydrogen-containing etchant gases (e.g., H₂), fluorine-containing etchant gases (e.g., CF₄, SF₆, CH₂F₂, CHF₃, and / or C₂F₆), oxygen-containing gases, chlorine-containing gases (e.g., Cl₂, CHCl₃, CCl₄, and / or BCl₃), bromine-containing gases (e.g., HBr and / or CHBr₃), iodine-containing gases, helium, and / or other suitable gases and / or plasma. In one embodiment, dry etching is performed using a mixture of N₂ and H₂ gases.

[0056] See Figure 15 . The exposed portion of the p-type WFM layer 308 in the gate trench 220 is removed using an etching process, thereby exposing the high-k dielectric layer 304 above the fins 207 a and 207 b. In other words, the p-type WFM layer 308 is patterned by removing the p-type WFM layer 308 above the fins 207 a and 207 b, leaving the p-type WFM layer 308 above the fins 207 c and 207 d. Any suitable etching process, including dry etching, wet etching, RIE, and / or other suitable processes, can be used. Suitable etchants, such as standard cleaning solutions SC1 (containing NH 4 OH or other suitable alkaline solutions) and SC2 (containing hydrochloric acid, phosphoric acid, sulfuric acid, or other acidic solutions), can be used to selectively etch the p-type WFM layer 308. Although p-type WFM layer 308 is in direct contact with high-k dielectric layer 304, the etching process does not remove or otherwise damage high-k dielectric layer 304 due to the etch selectivity between p-type WFM layer 308 and high-k dielectric layer 304. In some embodiments, the etchant removes p-type WFM layer 308 at a rate at least 100 times faster than that of high-k dielectric layer 304. This significant difference in etching rate ensures that the removal of the exposed portion of p-type WFM layer 308 does not substantially remove or otherwise damage any portion of high-k dielectric layer 304. Because protective layer 402 is free of defects, such as voids, the remaining portion of p-type WFM layer 308 can be protected by protective layer 402 from damage during etching processes, such as wet etching.

[0057] See Figure 16. The protective layer 402, the optional intermediate layer 403, and the photoresist layer 404 are removed by any suitable etching process. [ , , ]

[0058] See FIG. 17 . An n-type WFM layer 310 is formed in gate trench 220 and on patterned p-type WFM layer 308. In some embodiments, n-type WFM layer 310 is designed (in terms of material and / or thickness) to tune or modulate the threshold voltage of fins 207 a - 207 d. N-type WFM layer 310 may include a metal with a sufficiently low work function selected from, but not limited to, the following: titanium (Ti), aluminum (Al), titanium aluminum (TiAl), titanium aluminum carbide (TiAlC), titanium aluminum nitride (TiAlN), tantalum carbide (TaC), tantalum silicon carbide (TaSiC), tantalum aluminum carbide (TaAlC), tantalum carbonitride (TaCN), tantalum silicon nitride (TaSiN), titanium silicon nitride (TiSiN), niobium aluminum carbide (NbAlC), hafnium carbide (HfC), or combinations thereof. The n-type WFM layer 310 may be formed by a deposition process such as ALD, CVD, PVD, and / or other suitable processes. Depending on the desired work function on the fins 207a-207d, the n-type WFM layer 310 may be formed to a suitable thickness (e.g., about 2 nm to about 3 nm). [ , , ]

[0059] See FIG. 18 . A fill metal layer 320 is formed in the remaining space of the gate trench 220 to complete the metal gate structure. The fill metal layer 320 is disposed above and in direct contact with the n-type WFM layer 310. The fill metal layer 320 may include copper (Cu), tungsten (W), aluminum (Al), cobalt (Co), and / or other suitable materials. The fill metal layer 320 may be formed by ALD, CVD, PVD, electroplating, and / or other suitable processes. A CMP process may be performed to remove excess material and planarize the top surface of the semiconductor device 200. After forming the fill metal layer 320, the gate structure is completed. The gate structure (including the interface layer 302, the high-k dielectric layer 304, the p-type WFM layer 308, the n-type WFM layer 310, and the fill metal layer 320) is formed above and surrounding the channel, which is located between the source and drain on each fin. Therefore, each fin is part of a FinFET that includes a source, drain, channel, and gate. When multiple sources, drains, and channels are implemented on a fin, the fin can be considered part of multiple FinFETs. [ , , ]

[0060] FIG19 is a cross-sectional view taken along line BB of FIG18 according to some embodiments. An interface layer 302, a high-k dielectric layer 304, a p-type WFM layer 308, an n-type WFM layer 310, and a fill metal layer 320 are filled in the gate trench 220. The interface layer 302 covers the sidewalls of the gate spacer 212 and the bottom of the gate trench 220. The high-k dielectric layer 304 covers the interface layer 302. The p-type WFM layer 308 covers the high-k dielectric layer 304. The n-type WFM layer 310 covers the p-type WFM layer 308. The fill metal layer 320 is disposed on the n-type WFM layer 310. Source / drain regions 70 are formed in the fin 207d and separated by the channel region 230d. In some embodiments, the source / drain regions 70 are formed by epitaxial growth. The source / drain regions 70 are epitaxial layers. The source / drain regions 70 may include one or more layers of Si, SiP, SiC, and SiCP for n-channel FETs, or one or more layers of Si, SiGe, or Ge for p-channel FETs. A contact structure CS is disposed in the ILD layer 218 to electrically contact the source / drain regions 70. In some embodiments, the source / drain regions 70 include a conductive material such as cobalt (Co), tungsten (W), ruthenium (Ru), iridium (Ir), nickel (Ni), osmium (Os), rhodium (Rh), aluminum (Al), molybdenum (Mo), other suitable conductive materials, or combinations thereof. In some other embodiments, the p-type WFM layer 308 is replaced by an n-type WFM layer, and the n-type WFM layer 310 is replaced by a p-type WFM layer.

[0061] Based on the above discussion, it can be seen that the present disclosure provides a composition for forming a protective layer (e.g., a BARC) and a method for manufacturing a semiconductor device using the protective layer. Because the composition has high gap-filling capability, high wet etch resistance, and good adhesion to metal layers (e.g., p-type WFM layers and n-type WFM layers), the protective layer can protect the metal layer covering a substrate having protrusions and gaps in the semiconductor device from damage during the etching process. As a result, the semiconductor device can achieve good electrical performance.

[0062] In some embodiments, a method for manufacturing a semiconductor device includes the following operations: forming a protective layer over a substrate, wherein the protective layer is formed from a composition comprising a polymer having a polymer backbone and a plurality of end groups. The polymer backbone is formed by polymerizing a monomer composition comprising a plurality of first monomers, each of which independently has an aromatic group substituted with 1, 2, 3, 4, or 5 hydroxyl groups. The end groups include: 、 、 、 、 、 or a combination thereof. A is a substituted or unsubstituted hydrocarbon group. B is a hydroxyl group, an alkyl group, or a fluoroalkyl group. A photoresist layer is formed over the protective layer. The photoresist layer is patterned. [ , , ]

[0063] In some embodiments, a method of manufacturing a semiconductor device includes forming a bottom anti-reflective coating (BARC) over a substrate, wherein the BARC is formed from a composition including a first polymer having a first polymer backbone. The first polymer backbone is substituted with one or more functional groups including: 、 、 、 、 、 or a combination thereof. A is a substituted or unsubstituted hydrocarbon group. B is a hydroxyl group, an alkyl group, or a fluoroalkyl group. A photoresist layer is formed on the bottom anti-reflective coating. The photoresist layer is patterned. [ , , ]

[0064] In some embodiments, the composition includes a polymer, a crosslinking agent, and a solvent. The polymer has a polymer backbone and a plurality of first terminal units, wherein the polymer backbone and the first terminal units are independently unsubstituted or comprise 、 、 、 、 、 or a combination thereof. A is a substituted or unsubstituted hydrocarbon group. B is a hydroxyl group, an alkyl group, or a fluoroalkyl group. The polymer backbone, the first terminal units, or a combination thereof are substituted. [ , , ]

[0065] The foregoing summarizes the features of some embodiments to provide a better understanding of the aspects of the present disclosure. Those skilled in the art will appreciate that they may readily use this disclosure as a basis for designing or modifying other processes and structures for carrying out 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 that various changes, substitutions, and replacements may be made herein for such equivalent constructions without departing from the spirit and scope of the present disclosure.

[0066] 70: Source / Drain Region 200:Semiconductor devices 202:Substrate 203: District 1 205: District 2 207a~207d: fins 208: Isolation Structure 212: Gate spacer 218: Interlayer dielectric (ILD) layer 220: Gate trench 222: Gate trench 230a~230d: channel area 302: Interface layer 304: High-k dielectric layer 305: Gate dielectric layer 308: p-type WFM layer 310: n-type WFM layer 320: Filling metal layer 402: Protection layer 403: Optional middle layer 404: Photoresist layer AD: Additive CL: crosslinker CS: Contact structure EG1: end group EG2: end group EM: Etch Mask EU1: End Unit EU2: End Unit FG1: Functional group FG2: functional group G1: Group G2: Group GB1: Grain Boundary GB2: Grain Boundary G: Gap P1: polymer P2: polymer P3: Polymer P4: Polymer RU1: Repeating unit RU2: Repeating Unit W: Gap width

[0067] Domestic storage information (please note the order of storage institution, date, and number) none Overseas deposit information (please note the order of deposit country, institution, date, and number) none

Claims

1. A method for manufacturing a semiconductor device, comprising: A protective layer is formed over a substrate, wherein the protective layer is formed of a composition comprising a polymer having a polymer backbone and a plurality of end groups, the polymer backbone being formed by polymerization of a monomer composition comprising a plurality of first monomers, each of the first monomers independently having an aryl group substituted with 1, 2, 3, 4 or 5 hydroxyl groups, the end groups comprising: , , , , , or combinations thereof, A being a substituted or unsubstituted hydrocarbon group, and B being a hydroxyl, an alkyl or a fluoroalkyl group, the polymer comprising a phenolic varnish polymer, a substituted poly(hydroxystyrene), an unsubstituted poly(hydroxystyrene), an acrylate polymer, a substituted polyethylene or combinations thereof, wherein the substituted poly(hydroxystyrene) and the substituted polyethylene are respectively substituted with hydroxyphenyl, dihydroxyphenyl, trihydroxyphenyl, tetrahydroxyphenyl, pentahydroxyphenyl or combinations thereof; a photoresist layer is formed over the protective layer; and the photoresist layer is patterned.

2. The method as described in Request 1, wherein is , or , and n is 1 to 2.

3. The method as described in request item 1, wherein , , , , or .

4. The method as described in Request 1, wherein is , or , and n is 1 to 2.

5. The method as described in request item 1, wherein , , , , or .

6. The method as described in Request 1, wherein is , or , and n is 1 to 2, is , , , or .

7. A method for manufacturing a semiconductor device, comprising: A bottom antireflective coating is formed over a substrate, wherein the bottom antireflective coating is formed from a composition comprising a first polymer, the first polymer comprising a first polymer backbone having a first polymer backbone being substituted by one or more functional groups comprising: A, B, C, D, E, F, G ...

8. The method as described in claim 7, wherein the first polymer backbone has a plurality of repeating units, the repeating units comprising: R1 and R2 are independently monohydroxyphenyl, dihydroxyphenyl, trihydroxyphenyl, tetrahydroxyphenyl or pentahydroxyphenyl, and these repeating units are substituted by the functional group.

9. The method of claim 7, wherein the composition further comprises a second polymer having a second polymer backbone and a plurality of end groups, the end groups comprising: A, B, C, D, E, F ...

10. A composition for forming a protective layer, comprising: A polymer having a polymer backbone and a plurality of first terminal units, wherein the polymer backbone and the first terminal units are independently unsubstituted or independently substituted by one or more functional groups including , , , , , or combinations thereof, A being a substituted or unsubstituted hydrocarbon group, B being a hydroxyl, an alkyl, or a fluoroalkyl group, and the polymer backbone, the first terminal units, or combinations thereof being substituted; a crosslinking agent; and a solvent.

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