TW202009280A - Coating compositions for use with an overcoated photoresist - Google Patents

Abstract

Organic coating compositions, particularly antireflective coating compositions for use with an overcoated photoresist, are provided that comprise (1) one or more resins and (2) one or more PDQ compounds that are distinct from the (1) one or more resins.

Description

Coating composition for use with overcoat photoresist

The present invention relates to a composition for microelectronics applications, and specifically an anti-reflective coating composition (for example, "BARC"). The compositions of the present invention include one or more substituted photodegradable quencher compounds.

The photoresist is a photosensitive film used to transfer an image to a substrate. A photoresist coating is formed on the substrate, and the photoresist layer is then exposed to the activation radiation source through a photomask. After exposure, the photoresist is developed to provide a relief image that permits selective processing of the substrate.

The reflection of the radiation activated to expose the photoresist often limits the resolution of the patterned image in the photoresist layer. Reflecting the radiation from the substrate/photoresist interface can produce a spatial change in the radiation intensity in the photoresist, resulting in an uneven photoresist linewidth during development. Radiation can also be dispersed from the substrate/photoresist interface into the unexpected exposure area of the photoresist, again causing line width changes. One method for reducing the reflected radiation problem is to use a radiation absorbing layer interposed between the surface of the substrate and the photoresist coating. See U.S. 2016/0187778. See also US2011/0200935; US2012/0258405; and US2015/0346599.

Electronic device manufacturers are constantly seeking to increase the resolution of photoresists patterned on anti-reflective coatings.

We now provide new coating compositions that can be used with overcoat photoresist compositions. In a preferred aspect, the coating composition of the present invention can serve as an effective anti-reflection layer for overcoating a resist layer.

Preferred coating compositions may include 1) one or more resins (sometimes referred to herein as matrix resins) and 2) one or more substituted photodegradable quencher compounds different from 1) one or more resins ( PDQ) compounds.

Without being bound by any theory, Xianxin uses the preferred PDQ compounds as disclosed herein to enable the photo-acid to coat the exposed area of the resist layer from outside to the unexposed area of the coated substrate, including the resist layer/underlayer interface The migration of unexposed areas is minimized. That is, the PDQ in the bottom layer can suppress the undesired flow of photogenerated acid to the unexposed areas of the resist and the undercoat layer.

I have found that the use of one or more preferred PDGs in the primer coating composition can provide enhanced lithography results. See the comparison results described in the examples below.

In one aspect, the preferred PDQ compound will react when exposed to the radiation used to image the overcoated photoresist layer. Exemplary imaging radiation is 193 nm and EUV. In detail, the preferred PDQ compounds will react to release after exposure to radiation used to image the overcoated photoresist layer and post-exposure baking (eg, treatment at 100°C for 30 to 60 seconds), such as The acidic anion component is released by the dissociation of the ion complex (.e. onium salt).

In another aspect, the preferred PDQ compound is a non-polymeric compound. Suitable PDQ compounds may have a molecular weight of less than 3,000, or more generally less than 2500, or less than 2000, or less than 1500, or less than 1000, or less than 800, 700, 600 or 500.

In another aspect, the preferred PDQ compound is an ionic compound. The preferred ionic compound for use as a PDQ compound is an onium salt, such as a carbamide or a gallium compound.

In another aspect, the preferred PDQ compound may have a high pKa anion (eg, sulfamate with pKa greater than 0 or carboxylate with pKa greater than 3). As mentioned herein, the pKa value is in an aqueous solution at 23°C and can be measured or calculated experimentally, for example, using Advanced Chemistry Development (ACD) laboratory software version 11.02.

It is preferable that the acid generated by the PDQ is weaker than the acid generated by the photoacid generator compound overcoated with the resist layer. Therefore, without being bound by theory, since the strong acid generated in the exposed area by the photoacid generator migrates to the bottom area of the unexposed photoresist, and then light with a higher pKa in the unexposed area can destroy the quenching The quencher quenches the strong acid that diffuses from the exposed area. This can lead to strong acid neutralization in unexposed areas.

Therefore, in some preferred aspects, the pKa difference between the acidic component of the PDQ in the primer coating composition and the acidic component of the photoacid generator compound overcoated with the photoresist composition layer will be 0.5 , 1, 2, 3, or 4 or greater.

其中R₁ 及R₂ 各獨立地為氫、經取代或未經取代之烷基（例如C₁ -C₁₂ 烷基）、經取代或未經取代之環烷基（例如C₃ -C₁₂ 環烷基）或經取代或未經取代之芳基（例如5至12員芳基或苯基）；且Y為陽離子，諸如鋶陽離子。Particularly preferred PDQ compounds may include formula (A),

Where R ₁ and R _{2 are} each independently hydrogen, substituted or unsubstituted alkyl (eg C ₁ -C ₁₂ alkyl), substituted or unsubstituted cycloalkyl (eg C ₃ -C ₁₂ ring Alkyl) or substituted or unsubstituted aryl (eg 5 to 12 member aryl or phenyl); and Y is a cation, such as a cation.

其中R₃ 為經取代或未經取代之烷基（例如C₁ -C₁₂ 烷基）、經取代或未經取代之環烷基（例如C₃ -C₁₂ 環烷基）或經取代或未經取代之芳基（例如5至12員芳基或苯基）；且Y為陽離子，諸如鋶陽離子。Also particularly preferred PDQ compounds may include formula (B),

Where R ₃ is substituted or unsubstituted alkyl (eg C ₁ -C ₁₂ alkyl), substituted or unsubstituted cycloalkyl (eg C ₃ -C ₁₂ cycloalkyl) or substituted or unsubstituted A substituted aryl group (for example, a 5 to 12-membered aryl group or a phenyl group); and Y is a cation, such as a cation.

In some preferred aspects, one or more resins may also include one or more PDQ moieties as pendant groups or integral units of the resin chain.

The coating composition of the present invention may also include a crosslinking agent component different from the PDQ compound and resin. In the preferred crosslinking composition, the coating of the composition can be hardened or crosslinked after heat treatment at 180°C, 200°C or 250°C or higher for 60, 90, 120 or 180 seconds.

For anti-reflection applications, the primer composition of the present invention also preferably contains a component that includes a chromophore that can absorb undesired radiation used to expose the outer coating resist layer so as not to reflect back to the resist剂层中。 Agent layer. The matrix polymer or substituted PDQ compound may include such a chromophore, or the coating composition may include another component that includes a suitable chromophore.

The particularly preferred coating composition of the present invention may also contain a thermal acid (TAG) generator compound, which promotes the hardening of the applied composition coating. Preferred coating compositions may include 1) one or more resins (sometimes referred to herein as matrix resins); 2) one or more substituted photodegradable quencher compound (PDQ) compounds, which are different from 1) One or more resins; and 3) one or more thermal acid generator compounds (TAG), which are different from 1) one or more resins and 2) one or more PDQ compounds. The preferred primer coating composition may further include a crosslinker component, which is different from 1) one or more resins, 2) one or more PDQ compounds, and 3) one or more TAGs.

When used with overcoated photoresists, the coating composition may be applied to a substrate such as a semiconductor wafer, which may have one or more organic or inorganic coatings. The applied coating may optionally be heat-treated before overcoating with the photoresist layer. In the case of cross-linked compositions, such heat treatment can cause hardening, including cross-linking of the coating composition layer. Such crosslinking may include hardening and/or covalent bonding formation reactions between one or more composition components, and may adjust the water contact angle of the coating composition layer.

Thereafter, the photoresist composition may be coated on the coating composition layer, and then the coated photoresist composition layer is imaged by patterned activation radiation, and the imaged photoresist combination The object layer is developed to obtain a photoresist relief image.

Various photoresists can be used in combination with the coating composition of the present invention (ie, overcoating). The preferred photoresist used with the primer composition of the present invention is a chemically amplified resist, especially positive and negative photoresists containing one or more photoactive compounds and resin components, The resin component contains units that undergo deblocking or cleavage reactions in the presence of photo-generated acids.

In some preferred aspects, the photoresist composition is designed for negative resists, where the exposed area remains after the development process, but positive development can also be used to remove the photoresist layer Exposure part.

The present invention additionally provides a method of forming a photoresist relief image and a novel article including a substrate (such as a microelectronic wafer substrate) which is coated with the present invention alone or in combination with a photoresist composition The composition is applied.

Other aspects of the invention are disclosed below.

We now provide new organic coating compositions which are particularly suitable for overcoating photoresist layers. As discussed above, the preferred coating composition may include 1) matrix polymer; and 2) one or more PDQ compounds. The preferred coating composition of the present invention can be applied by spin coating (spin coating composition) and formulated as a solvent composition. The coating composition of the present invention is particularly suitable as an anti-reflective composition for overcoating photoresist and/or as a planarization or through-hole filling composition for overcoating of the photoresist composition.

其中R₁ 及R₂ 各獨立地為氫、經取代或未經取代之烷基（例如C₁ -C₁₂ 烷基）、經取代或未經取代之環烷基（例如C₃ -C₁₂ 環烷基）、或經取代或未經取代之芳基（例如5至12員芳基或苯基）；且Y為陽離子，諸如鋶基團。Particularly preferred PDQ compounds may have formula (A),

Where R ₁ and R _{2 are} each independently hydrogen, substituted or unsubstituted alkyl (eg C ₁ -C ₁₂ alkyl), substituted or unsubstituted cycloalkyl (eg C ₃ -C ₁₂ ring Alkyl), or substituted or unsubstituted aryl (eg, 5 to 12 member aryl or phenyl); and Y is a cation, such as a carbamoyl group.

Preferably, R ₁ and R _{2 are} independently hydrogen or C ₁ -C ₄ alkyl, which may be optionally substituted with methyl, ethyl, cyclohexyl, cyclopentyl, and adamantyl. Other preferred R ₁ and R _{2 are} independently C ₃ -C ₁₂ cycloalkyl, such as cyclohexyl, cyclopentyl and adamantyl.

Preferably Y is C ₁ -C ₁₂ alkyl, 2-8 member heteroalkyl, C ₃ -C ₁₂ cycloalkyl, 5 to 12 member heterocycloalkyl, or 5 to 12 member aryl (eg phenyl , Naphthyl or anthracenyl), each of which is optionally substituted with C ₁ -C ₃ alkyl or C ₃ -C ₁₂ cycloalkyl. Other preferred Y is a cation having phenyl, cyclopentyl, cyclohexyl, adamantyl, methyl, ethyl, propyl, butyl, tertiary butyl, or isopropyl, each of which is regarded as The case is substituted with a linear or branched C ₁ -C ₄ alkyl group, such as methyl, ethyl, propyl, butyl, tertiary butyl or isopropyl. Further preferred Y includes 5-6 membered heterocycloalkyl, which is formed by a sulfur atom together with an alkyl substituent.

。Exemplary preferred anions Y can include:

.

。Exemplary PDQ compounds of formula (A) may include:

.

其中R₃ 為經取代或未經取代之烷基（例如C₁ -C₁₂ 烷基）、經取代或未經取代之環烷基（例如C₃ -C₁₂ 環烷基）或經取代或未經取代之芳基（例如5至12員芳基或苯基）；且Y描述於本文中。較佳R₃ 可包含C₁ -C₄ 烷基，其可為直鏈或分支鏈且視情況經取代的。其他較佳R₃ 為C₃ -C₁₂ 環烷基，諸如環己基、環戊基及金剛烷基，或為苯基，其可視情況經取代。Also particularly preferred PDQ compounds may include formula (B),

Where R ₃ is substituted or unsubstituted alkyl (eg C ₁ -C ₁₂ alkyl), substituted or unsubstituted cycloalkyl (eg C ₃ -C ₁₂ cycloalkyl) or substituted or unsubstituted Substituted aryl (eg 5 to 12 member aryl or phenyl); and Y are described herein. Preferably R ₃ may comprise C ₁ -C ₄ alkyl, which may be linear or branched and optionally substituted. Other preferred R ₃ is C ₃ -C ₁₂ cycloalkyl, such as cyclohexyl, cyclopentyl, and adamantyl, or phenyl, which may be substituted as appropriate.

。Exemplary PDQ compounds of formula (B) may include:

.

PDQ compounds are commercially available or can be easily synthesized. See the example below.

As mentioned herein, suitable heteroalkyl groups include optionally substituted C ₁ -C ₂₀ alkoxy groups, preferably optionally substituted alkylthio groups having 1 to about 20 carbon atoms; preferably 1 An optionally substituted alkylsulfinyl group of up to about 20 carbon atoms; an optionally substituted alkylsulfinyl group having preferably 1 to about 20 carbon atoms; and preferably 1 to about 20 carbon atoms An optionally substituted alkylamine with carbon atoms.

"Substituted as appropriate" various materials and substituents may be suitably substituted at one or more available positions with, for example, the following: halogen (F, Cl, Br, I); nitro; hydroxyl; amine; alkyl group, such as C ₁ - ₄ alkyl group; an alkenyl group such as a C _2-8 alkenyl group; alkylamino such as C _1-8 alkylamino; carbocyclic aryl group such as phenyl, naphthyl, anthryl and the like; And similar groups.

Preferably, one or more resins and one or more substituted PDQ compounds are different materials, that is, one or more resins and one or more substituted PDQ compounds are not covalently linked.

One or more substituted PDQ compounds are suitably 0.1% by weight to 10, 15, 20, 30, 40 or more weight% based on the total solid weight of the coating composition, more typically based on the total solid weight of the coating composition An amount of 1, 2, or 3% by weight to 5, 10, 15, or 20 or more% by weight is present in the coating composition. Total solids mentioned in this article

Various resins can serve as the matrix polymer of the primer composition.

The particularly preferred matrix resin of the coating composition of the present invention may include polyester bonds. Polyester resins can be easily prepared by reacting one or more polyol reagents with one or more carboxyl-containing (such as carboxylic acid, ester, anhydride, etc.) compounds. Suitable polyol reagents include glycols, glycerol and triols, such as glycols, such as glycols are ethylene glycol, 1,2-propanediol, 1,3-propanediol, butanediol, pentanediol, cyclobutyl di Alcohol, cyclopentyl diol, cyclohexyl diol, dimethylol cyclohexane, and triols, such as glycerol, trimethylolethane, trimethylolpropane and the like.

The matrix resin of the coating composition of the present invention may include various additional groups, such as cyanurate groups, as disclosed in US Pat. Nos. 6,852,421 and 8,501,383.

The particularly preferred matrix resin of the coating composition of the present invention may include one or more one or more cyanurate groups and polyester bonds.

As discussed, for anti-reflection applications, it is appropriate that one or more of the compounds reacted to form the resin include a portion that can act as a chromophore to absorb the photoresist coating used for exposure overcoating radiation. For example, phthalate compounds (such as phthalic acid or dialkyl phthalates (ie diesters, such as esters each having 1 to 6 carbon atoms, preferably phthalic acid Dimethyl formate or diethyl phthalate) can be polymerized with aromatic or non-aromatic polyols and optionally other reactive compounds to provide polyesters that are particularly suitable for coating compositions, the coating composition Used with photoresists that image at wavelengths below 200 nm (such as 193 nm). PDQ compounds can also be polymerized with one or more polyols to provide resins suitable for the primer composition of the present invention. The resin in the composition coated with a photoresist other than imaging at a wavelength below 300 nm or a wavelength below 200 nm (such as 248 nm or 193 nm), the naphthyl compound may be polymerized, such as containing one or two or more carboxyl group of substituted naphthalene compounds, e.g. dialkyl particularly di -C ₁ -. ₆ alkyl naphthalene dicarboxylate reactive anthracene compound also preferred, having one or more carboxyl groups e.g. Or an ester group, such as one or more methyl or ethyl anthracene compounds.

The compound containing the chromophore unit may also contain one or preferably two or more hydroxyl groups and react with the carboxyl group-containing compound. For example, a phenyl compound or anthracene compound having one, two or more hydroxyl groups can be reacted with a carboxyl group-containing compound.

In addition, the primer composition for anti-reflection purposes may contain a material containing a chromophore unit, and the chromophore unit and a resin component that provides water contact angle adjustment (for example, containing a photoacid-labile group and/or Resin separation of alkali-reactive groups. For example, the coating composition may include polymerized or non-polymerized compounds containing units such as phenyl, anthracene, naphthyl, etc. However, it is generally preferred to provide one of water contact angle adjustment or Many resins also contain chromophore moieties.

Preferably, the weight average molecular weight (Mw) of the matrix resin of the primer composition of the present invention will be about 1,000 to about 10,000,000 Daltons, more typically about 2,000 to about 100,000 Daltons, and the number average molecular weight (Mn ) Is about 500 to about 1,000,000 Daltons. The molecular weight (Mw or Mn) of the polymer of the present invention is suitably determined by gel permeation chromatography.

In many preferred embodiments, the matrix polymer will be the main solid component of the primer composition. For example, the matrix polymer may suitably be present at 50 to 99.9% by weight based on the total solids content of the coating composition, more typically 80 to 95% by weight based on the total solids content of the coating composition. As mentioned herein, the solids of the coating composition refer to all materials of the coating composition except the solvent carrier.

As mentioned, the preferred primer composition of the present invention can be cross-linked, for example, by heat treatment and/or radiation treatment. For example, the preferred primer coating composition of the present invention may contain a separate crosslinker component, which may be crosslinked with one or more other components of the coating composition. Generally, the preferred crosslinked coating composition includes a separate crosslinker component.

A variety of cross-linking agents can be used, including those disclosed in European Application 542008. For example, suitable coating composition cross-linking agents include amine-based cross-linking agents, such as melamine materials, including melamine resins, such as manufactured by Cytec Industries and sold under the trade names Cymel 300, 301, 303, 350, 370, 380, 1116 and 1130 sold. The glycolurils are particularly preferred and include glycolurils purchased from Cytec Industries. Materials based on benzoquinamine and urea will also be suitable, including resins such as benzoquinamine resins purchased from Cytec Industries under the trade names Cymel 1123 and 1125, and from Cytec Industries under the trade names Powderlink 1174 and 1196. Urea resin. In addition to being commercially available, such amine-based resins can be obtained, for example, by reacting acrylamide or methacrylamide copolymers with formaldehyde in an alcohol-containing solution, or by allowing N-alkoxymethacrylamide It is prepared by copolymerizing amine or methacrylamide with other suitable monomers.

The crosslinking agent component of the coating composition of the present invention is generally in an amount of between about 5 and 50% by weight of the total solids of the coating composition (all components except the solvent carrier), more typically about 5 to 25 The weight percent total solids are present.

As discussed, the particularly preferred coating compositions of the present invention may also contain thermal acid (TAG) generator compounds. It is generally preferable to thermally induce the cross-linked coating composition by activating the thermal acid generator. As discussed, the primer coating composition layer may be suitably coated on the surface of the substrate that is heat treated to activate, that is, generate released acid from the TAG and harden or crosslink one or more composition components. Thereafter, the photoresist layer may be coated on the hardened base layer.

Suitable thermal acid generator compounds for coating compositions include ionic or substantially neutral thermal acid generators, such as ammonium aromatic sulfonate (eg, ammonium tosylate), used in the curing process of anti-reflective composition coatings Catalyze or promote crosslinking. Generally, the concentration of one or more thermal acid generators in the coating composition is about 0.1 to 10% by weight based on the total dry components of the composition (all components except the solvent carrier), more preferably the total dry group About 0.5 to 2% by weight.

The coating composition of the present invention, especially for reflection control applications, may also contain additional dye compounds that absorb the radiation used to coat the photoresist layer over the exposure. Other optional additives include surface leveling agents, such as the leveling agent available under the trade name Silwet 7604, or the surfactants FC 171 or FC 431 from 3M Company.

The primer coating composition of the present invention may also contain other materials, such as photoacid generators, including photoacid generators as discussed in conjunction with overcoating photoresist compositions. For a discussion of such uses of photoacid generators in anti-reflective compositions, see US Patent 6,261,743.

To prepare the liquid coating composition of the present invention, the components of the coating composition are dissolved in a suitable solvent, such as one or more oxyisobutyrate, specifically 2-hydroxyisobutyric acid methyl ester, ethyl lactate Or one or more of glycol ethers, such as 2-methoxyethyl ether (diethylene glycol dimethyl ether), ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; solvents with ether and hydroxyl moieties, such as methyl ether Oxybutanol, ethoxybutanol, methoxypropanol, and ethoxypropanol; 2-hydroxyisobutyric acid methyl ester; esters, such as cellosolve methyl acetate, cellosolve ethyl acetate, Propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and other solvents such as dibasic esters, propylene carbonate, and γ-butyrolactone. The concentration of the dry component in the solvent will depend on several factors, such as the method of application. Generally speaking, the solids content of the primer coating composition varies from about 0.5 to 20% by weight of the total weight of the coating composition, preferably, the solids content varies from about 0.5 to 10% by weight of the coating composition. Exemplary photoresist system

The photoresist used with the primer coating composition generally includes a polymer and one or more acid generators. In general, a positive resist is preferred, and the resist polymer has a functional group that imparts basic water solubility to the resist composition. For example, a polymer including a polar functional group, such as a hydroxyl group or a carboxylate group, or an acid-labile group, which can release such a polar moiety after lithography treatment is preferable. Preferably, the polymer is used in the resist composition in an amount sufficient to allow the resist to be developed by an alkaline aqueous solution.

The acid generator is also suitably used with polymers including repeating units containing aromatic groups such as optionally substituted phenyl (including phenol), optionally substituted naphthyl, and apparently The situation is replaced by anthracene. Polymers containing optionally substituted phenyl (including phenol) are particularly suitable for many resist systems, including those that are imaged by EUV and electron beam radiation. For positive resists, the polymer also preferably contains one or more repeating units that include acid labile groups. For example, in the case of polymers containing optionally substituted phenyl or other aromatic groups, the polymer may include repeating units containing one or more acid labile moieties, such as by polymerizing acrylate or methyl It is a polymer formed from monomers based on acrylate compounds in acid-labile esters (such as third butyl acrylate or third butyl methacrylate). Such monomers can be copolymerized with one or more other monomers that include aromatic groups, such as phenyl, as the case may be, such as styrene or vinylphenol monomers.

其中各R^a 獨立地為H、F、-CN、C_1-10 烷基或C_1-10 氟烷基。在式（V）之可酸脫保護單體中，R^b 獨立地為C_1-20 烷基、C_3-20 環烷基、C_6-20 芳基、或C_7-20 芳烷基，且各R^b 為獨立的或至少一個R^b 鍵結至相鄰R^b 以形成環狀結構。在式（VI）之含內酯單體中，L為單環、多環或稠合多環C_4-20 含內酯基團。Preferred monomers for forming such polymers include: acid-labile monomers having the following formula (V), lactone-containing monomers or polarity-controlling monomers having the following formula (VI), or including the foregoing monomers Combination of at least one of:

Wherein each R ^a is independently H, F, -CN, C _1-10 alkyl or C _1-10 fluoroalkyl group. In the acid-deprotectable monomer of formula (V), R ^{b is} independently C _1-20 alkyl, C _3-20 cycloalkyl, C _6-20 aryl, or C _7-20 aralkyl, And each R ^b is independent or at least one R ^{b is} bonded to an adjacent R ^b to form a ring structure. In the lactone-containing monomer of formula (VI), L is a monocyclic, polycyclic or fused polycyclic C _4-20 lactone-containing group.

或包括前述中之至少一者之組合，其中R^a 為H、F、-CN、C_1-6 烷基、或C_1-6 氟烷基。Exemplary acid deprotectable monomers include (but are not limited to):

Or a combination comprising at least one of the foregoing, the wherein R ^a is H, F, -CN, C _1-6 alkyl, or C _1-6 fluoroalkyl group.

其中R^a 為H、F、-CN、C_1-6 烷基、或C_1-6 氟烷基，R為C_1-10 烷基、環烷基、或雜環烷基，且w為0至5之整數。在式（IX）中，R直接連接至內酯環或通常連接至內酯環及/或一或多個R基團，且酯部分直接、或經由R間接連接至內酯環。Suitable lactone monomers can have the following formula (IX):

Wherein R ^a is H, F, -CN, C _1-6 alkyl, or C _1-6 fluoroalkyl group, R is C _1-10 alkyl, cycloalkyl, or heterocycloalkyl, and w is 0 Integer to 5. In formula (IX), R is directly connected to the lactone ring or usually to the lactone ring and/or one or more R groups, and the ester moiety is directly or indirectly connected to the lactone ring via R.

或包括前述單體中之至少一者之組合，其中R^a 為H、F、-CN、C_1-10 烷基、或C_1-10 氟烷基。Exemplary lactone-containing monomers include:

Or a combination of the foregoing monomers at least one of wherein R ^a is H, F, -CN, C _1-10 alkyl, or C _1-10 fluoroalkyl group.

Particularly suitable polymers with acid-labile deblocking groups for the positive chemically amplified photoresist of the present invention have been disclosed in European Patent Application 0929766A2 (acetal polymers and ketal polymers) and European Patent Application EP0783136A2 (terpolymers and other copolymers containing 1) styrene; 2) hydroxystyrene; and 3) acid-labile groups, specifically alkyl acrylate acid-labile units .

其中：R₁ 為(C₁ -C₃ )烷基；R² 為(C₁ -C₃₎ 亞烷基；Li為內酯基；且n為1或2。Other preferred resins for photoresists for imaging below 200 nm (such as 193 nm) include units having the following general formulas (I), (II), and (III):

Wherein: R ₁ is (C ₁ -C ₃ ) alkyl; R ² is (C ₁ -C ₃₎ alkylene; Li is a lactone group; and n is 1 or 2.

The molecular weight and polydispersity of the polymer used in the photoresist of the present invention can be suitably varied widely. Suitable polymers include those having an _{Mw of} about 1,000 to about 50,000, more typically about 2,000 to about 30,000, and a molecular weight distribution of about 3 or less, more typically about 2 or less.

Preferred negative compositions of the present invention include materials that will cure, crosslink or harden when exposed to acid, and a mixture of two or more acid generators as disclosed herein. Preferred negative compositions include polymer binders (such as phenolic or non-aromatic polymers), crosslinker components, and photoactive components of the present invention. Such compositions and their uses have been disclosed in Thackeray et al. European Patent Application 0164248 and US Patent No. 5,128,232. Preferred phenolic polymers used as polymer binder components include novolak and poly(vinylphenol), such as those described above. Preferred crosslinking agents include amine-based materials (including melamine, glycoluril), benzoguanamine-based materials, and urea-based materials. Melamine-formaldehyde polymers are generally particularly suitable. Such cross-linking agents are commercially available, such as melamine polymers, glycoluril polymers, urea-based polymers and benzoguanamine polymers, such as Cymel 301, 303, 1170, 1171, 1172 1123 and 1125 and Beetle 60, 65 and 80 sold them.

The particularly preferred photoresist of the present invention can be used in immersion lithography applications. For a discussion of preferred immersion lithography photoresists and methods, see, for example, U.S. 7968268 issued to Rohm and Haas Electronic Materials.

The photoresist of the present invention may also include a single acid generator or a mixture of different acid generators, usually a mixture of 2 or 3 different acid generators, and more usually a mixture of a total of 2 different acid generators . The photoresist composition includes an acid generator in an amount sufficient to produce a latent image in the coating of the composition when exposed to activating radiation. For example, the acid generator will suitably be present in an amount of 1 to 20% by weight based on the total solids of the photoresist composition.

Suitable acid generators are known in the field of chemically amplified photoresists and include, for example, onium salts, such as triphenylmethanesulfonate trifluoromethanesulfonate, trifluoromethanesulfonic acid (p-third butoxybenzene Group) diphenyl alkane, trifluoromethanesulfonic acid tris(p-third butoxyphenyl) alkane, p-toluenesulfonic acid triphenyl alkane; nitrobenzyl derivatives, such as p-toluenesulfonic acid nitro Benzyl methyl ester, 2,6-dinitrobenzyl p-toluenesulfonate and 2,4-dinitrobenzyl p-toluenesulfonate; sulfonate, such as 1,2,3-tris(methanesulfonamide Yloxy)benzene, 1,2,3-tris(trifluoromethanesulfonyloxy)benzene and 1,2,3-tris(p-toluenesulfonyloxy)benzene; diazomethane derivatives, for example Bis(benzenesulfonyl)diazomethane, bis(p-toluenesulfonyldiazomethane; oxime derivatives, such as bis-O-(p-toluenesulfonyl)-α-dimethylglyoxime and Bis-O-(n-butanesulfonyl)-α-dimethylglyoxime; sulfonate derivatives of N-hydroxyimidimide compounds, such as N-hydroxysuccinimide mesylate, N-hydroxysuccinimide trifluoromethanesulfonate; and halogen-containing triazine compounds, such as 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1, 3,5-triazine, and 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine.

As mentioned herein, the acid generator may generate acid when exposed to activating radiation, such as EUV radiation, electron beam radiation, 193 nm wavelength radiation, or other radiation sources. The acid generator compound as mentioned herein may also be referred to as a photo acid generator compound.

The photoresist of the present invention may also contain other materials. For example, other optional additives include actinic and contrast dyes, anti-striation agents, plasticizers, speed enhancers, and sensitizers. Such optionally present additives will generally be present in the photoresist composition in relatively small concentrations.

Alternatively or additionally, other additives may include a quencher, which is a non-photodestructible base, such as those based on hydroxides, carboxylates, amines, imines, and amides. Preferably, such quenchers include C _1-30 organic amines, imines or amides, or C _{1 which} may be a strong base (such as hydroxide or alkoxide) or a weak base (such as carboxylate) _-30 quaternary amine salt. Exemplary quenchers include amines such as tripropylamine, dodecylamine, tris(2-hydroxypropyl)amine, tetrakis(2-hydroxypropyl)ethylenediamine; arylamines such as diphenylamine, triphenylamine, amine Phenol and 2-(4-aminophenyl)-2-(4-hydroxyphenyl)propane, hindered amines, such as diazabicycloundecene (DBU) or diazabicyclononene (DBN) , Or an ion quencher containing a quaternary alkyl ammonium salt, such as tetrabutylammonium hydroxide (TBAH) or tetrabutylammonium lactate.

Surfactants include fluorinated and non-fluorinated surfactants, and are preferably non-ionic. Exemplary fluorinated nonionic surfactants include perfluoro C ₄ surfactants, such as FC-4430 and FC-4432 surfactants available from 3M Corporation; and fluorodiols, such as POLYFOX PF- available from Omnova 636, PF-6320, PF-656 and PF-6520 fluorine surfactants.

The photoresist further includes a solvent generally suitable for dissolving, dispensing, and coating the components used in the photoresist. Exemplary solvents include anisole; alcohols containing ethyl lactate, 1-methoxy-2-propanol, and 1-ethoxy-2 propanol; containing n-butyl acetate, 1-methoxy-2 acetate -An ester of propyl ester, methoxyethoxypropionate, ethoxyethoxypropionate; a ketone containing cyclohexanone and 2-heptanone; and a combination including at least one of the foregoing solvents. Lithography

In use, the coating composition of the present invention is applied to the substrate as a coating by any of a variety of methods, such as spin coating. The coating composition is generally applied on a substrate, wherein the thickness of the dried layer is between about 0.02 and 0.5 µm, preferably the thickness of the dried layer is between about 0.04 and 0.20 µm. The substrate is suitably any substrate used in a method involving photoresist. For example, the substrate may be silicon, silicon dioxide, or aluminum-alumina microelectronic wafers. Gallium arsenide, silicon carbide, ceramic, quartz or copper substrates can also be used. It is also appropriate to use substrates for liquid crystal display or other flat panel display applications, such as glass substrates, indium tin oxide coated substrates, and the like. Substrates for optical and optoelectronic devices (such as waveguides) can also be used.

Preferably, the applied coating is cured before applying the photoresist composition to the primer coating composition. The curing conditions will vary with the components of the primer coating composition. In particular, the curing temperature will depend on the specific acid or acid (heat) generator used in the coating composition. Typical curing conditions are about 80°C to 225°C for about 0.5 to 5 minutes. The curing conditions are preferably such that the coating composition coating is substantially insoluble in the photoresist solvent and the developer solution to be used.

After such curing, the photoresist is applied on the surface of the applied coating composition. As with the undercoat composition layer, the overcoat photoresist can be applied by any standard method, such as by spin coating, dipping, meniscus, or roll coating. After coating, the photoresist coating is usually dried by heating to remove the solvent, preferably until the resist layer is non-sticky. Optimally, basically no intermixing of the bottom composition layer and the overcoated photoresist layer should occur.

The resist layer is then imaged with activating radiation (such as 248 nm, 193 nm, or EUV radiation) via a mask in a conventional manner. The exposure energy is sufficient to effectively activate the photoactive components of the resist system to produce a patterned image in the resist coating. Generally, the exposure energy ranges from about 3 to 300 mJ/cm ² and depends in part on the exposure tool and the specific resist and resist treatment employed. The exposed resist layer may be subjected to post-exposure baking as necessary to create or enhance the solubility difference between the exposed and unexposed areas of the coating. For example, negative acid hardened photoresists generally require post-exposure heating to induce acid-promoted crosslinking reactions, and many chemically amplified positive resists require post-exposure heating to induce acid-promoted deprotection reactions. Generally, post-exposure baking conditions include a temperature of about 50°C or greater, more specifically, a temperature in the range of about 50°C to about 160°C.

The photoresist layer can also be exposed in an immersion lithography system, that is, the space between the exposure tool (specifically the projection lens) and the photoresist coated substrate is occupied by an immersion fluid, which is A mixture of additives such as water or water with one or more additives that provide fluids with enhanced refractive index, such as cesium sulfate. Preferably, the immersion fluid (eg water) has been treated to avoid air bubbles, for example water can be degassed to avoid nano air bubbles.

"Immersion exposure" or other similar terms referred to herein indicate exposure using such a fluid layer (such as water or water accompanied by additives) interposed between the exposure tool and the applied layer of photoresist composition .

The exposed photoresist layer is then treated with a suitable developer capable of selectively removing portions of the film to form a photoresist pattern. During negative development, the unexposed areas of the photoresist layer can be selectively removed by treatment with a suitable non-polar solvent. For suitable procedures for negative development, see U.S. 2011/0294069. Typical non-polar solvents used for negative development are organic developers, such as solvents selected from the group consisting of ketones, esters, hydrocarbons, and mixtures thereof, such as acetone, 2-hexanone, 2-heptanone, methyl acetate, butyl acetate Ester and tetrahydrofuran. The photoresist material used in the NTD process preferably forms a photoresist layer, which can be negatively formed with an organic solvent developer, or positively formed with an aqueous alkaline developer such as a tetraalkylammonium hydroxide solution Like. Preferably, the NTD photoresist is based on a polymer having acid-sensitive (removable protecting groups) groups, which form carboxylic acid groups and/or hydroxyl groups when the protecting groups are removed.

Alternatively, the development of the exposed photoresist layer can be achieved by processing the exposed layer into a suitable developer, which can selectively remove the exposed portion of the film (where the photoresist is positive Or remove the unexposed part of the film (where the photoresist can be cross-linked in the exposed area, that is, negative) is preferably based on having acid sensitivity to form a carboxylic acid group when the protective group is removed ( The polymer with removable protective group) group, the photoresist is positive, and the developer is preferably a tetraalkylammonium hydroxide solution that does not contain metal ions, such as 0.26 N tetramethylammonium hydroxide aqueous solution . The pattern is formed by development.

The developed substrate can then be selectively processed on the areas of their substrates without photoresist, such as chemical etching or plating on areas of the substrate without photoresist according to procedures well known in the art. Suitable etchant includes hydrofluoric acid etching solution and plasma gas etching, such as oxygen plasma etching. Plasma gas etching removes the undercoat layer.

The following non-limiting examples illustrate the invention. Example 1-2: PDQ Synthesis Example 1:

To a mixture of 75.0 parts of compound (a) (Tokyo Industrial Chemistry, Co., Ltd.) and 600 parts of chloroform, 240 parts of a 10% sodium hydroxide aqueous solution was added. The resulting mixture was stirred at room temperature for 1 hour, and then the organic layer was separated and dried. 106 parts of triethylamine was added to the filtered organic layer. The resulting mixture was cooled to -10°C, and 51.2 parts of compound (c) was added, followed by stirring at room temperature for 1 hour. The compound of formula (d) is then added, followed by overnight stirring and then water extraction. The obtained organic layer was concentrated under reduced pressure. The solid is purified to obtain compound (2). Example 2

To a mixture of 2.2 parts of compound (e) (Tokyo Industrial Chemistry, Co., Ltd.) and 50 parts of chloroform, 2.8 parts of triethylamine was added. The mixture was cooled to -10°C, and 1.6 parts of compound (f) was added, followed by stirring at room temperature. Then 4.0 parts of compound (g) was added to the reaction mixture, followed by stirring overnight and then water extraction. The obtained organic layer was concentrated under reduced pressure. The solid is purified to obtain compound (4). Example 3-6: Preparation of primer coating composition

Four different primer coating compositions (Examples 3 and 4, respectively) were prepared by blending materials (polymers, crosslinking agents, TAG, PDQ, solvents) of the type and amount specified in Table 1 below 5 and 6). The structure of the polymer, cross-linking agent, TAG, PDQ, and solvent of each of the compositions of Examples 3-6 follows Table 1. In each of Examples 3-6, the same polymer, crosslinker, TAG, and solvent and their amounts were used. The only difference in the example is the PDQ used and its amount (in Example 3, there is no PDQ). All weight percentages (% by weight) listed in Table 1 are based on the total solids of the coating composition (total solids are all materials of the composition except the solvent).

Table 1. Sample recipes

The structure of the polymer of each of Examples 3-6.

Example 3-6 cross-linking agent and TAG structure

Examples 4, 5 and 6 specify the structure of the PDQ.

Solvent for each of Examples 3-6. Example 7: Lithography evaluation

The coating compositions of each of Examples 3 to 6 were each spin-coated on 4 cm×4 cm wafers previously coated with 65 sold under the trade name AR46 by Dow Chemical nm cross-linked organic layer. The wafer coated with the composition of Examples 3-6 was then baked at 215°C for one minute using a micro coater. The thickness of the BARC coating after baking is 22 nm. A commercially available chemically amplified photoresist composition was then spin-coated on each of the samples with the coatings of Examples 3-6. The coated photoresist layer was soft baked at 110°C for 50 seconds, imaged through a mask with 193 nm radiation and then subjected to post-exposure baking at 95°C for 60 seconds.

The image samples were then treated with 0.26 N TMAH aqueous developer. The lithography results are described in Table 2 below. The coating system with PDQ in the primer coating composition showed better results, including wider focus latitude (FL) tolerance and improved pattern collapse performance. Figure 1 additionally shows a scanning electron micrograph of the imaged and developed sample. As shown in FIG. 1, Sample 1 is a sample imaged by the coating composition of Example 3; Sample 2 is a sample imaged by the coating composition of Example 4; Sample 3 is a sample imaged by the coating composition of Example 5; and Sample 4 is a sample imaged by the coating composition of Example 6; Table 2. Lithography results

Figure 1 shows scanning electron micrographs of imaged photoresist/undercoat samples and comparative samples.

Claims (13)

A method for forming a photoresist relief image, comprising: a) coating a coating composition layer on a substrate, the coating composition comprising: 1) a resin; and 2) a PDQ compound; and b) in the A layer of the photoresist composition is coated on the layer of the coating composition. The method as claimed in item 1 of the patent application, wherein the PDQ compound has an sulfamate anion or a carboxylate anion. A method as claimed in item 2 of the patent application, wherein the PDQ compound includes an anion with a pKa greater than zero. For example, in the method of claim 1, the PDQ compound has the structure of the following formula (A) or (B):

Wherein: R ₁ and R _{2 are} each independently hydrogen, substituted or unsubstituted C ₁ -C ₁₂ alkyl, substituted or unsubstituted C ₃ -C ₁₂ cycloalkyl, or substituted or unsubstituted Substituted phenyl; R ₃ is substituted or unsubstituted C ₁ -C ₁₂ alkyl, substituted or unsubstituted C ₃ -C ₁₂ cycloalkyl, or substituted or unsubstituted phenyl; And Y is a cation. For example, the method of applying for the fourth item of patent scope, where Y is:

. For example, the method of claim 4 or item 5, wherein R ₁ and R _{2 are} independently hydrogen, methyl, cyclohexyl, adamantyl or C ₁ -C ₃ alkyl substituted with adamantyl and/ Or R ₃ is adamantyl. The method according to any one of items 1 to 6 of the patent application scope, wherein the PDQ compound is:

. The method according to any one of claims 1 to 7, wherein the resin includes isocyanurate groups. The method according to any one of claims 1 to 8, wherein the coating composition further includes 1) a crosslinking agent component and/or 2) a thermal acid generator compound, each of which is different from the PDQ compound and the resin. A coated substrate comprising: a substrate having: a) a coating composition including: 1) a resin; and 2) a PDQ compound; and b) a photoresist on the coating composition layer Composition layer. A coating composition for use with an overcoat photoresist composition, the coating composition comprising: 1) a resin; and 2) a PDQ compound. The coating composition as claimed in item 11 of the patent application, wherein the PDQ compound includes an sulfamate anion or a carboxylate anion. For example, the coating composition of claim 11 or claim 12, wherein the coating composition further includes 1) a crosslinking agent component and/or 2) a thermal acid generator compound, each of which is different from the PDQ compound And the resin.

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