Metal chelators for development of metal-containing photoresist

Abstract

SOLUTION: The present disclosure relates to use of a metal chelator to treat an exposed photoresist film. In particular embodiments, the metal chelator is employed to remove an interfacial area that is disposed between exposed and unexposed areas or disposed within an exposed area, thereby enhancing patterning quality.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] Incorporation by Reference A PCT Request Form is being filed contemporaneously herewith as part of this application. Each application to which this application claims benefit or priority as identified in the contemporaneously filed PCT Request Form is incorporated herein by reference in its entirety for all purposes. This application claims the benefit of U.S. Provisional Patent Application No. 62 / 705,855, filed July 17, 2020, which provisional patent application is incorporated herein by reference in its entirety.

[0002] The present disclosure relates to the use of metal chelating agents to treat exposed photoresist films. In certain embodiments, the metal chelating agents are used to improve patterning quality by removing interfacial regions located between exposed and unexposed regions or located within exposed regions. [Background technology]

[0003] The description of the background art provided herein is intended to provide a general background to the present technology, and the work of the inventors named herein, to the extent described in this background art, together with aspects of the description that would not normally be considered prior art at the time of filing, are not admitted expressly or impliedly as prior art against the present technology.

[0004] Patterning of thin films in semiconductor processing is often a critical step during semiconductor manufacturing. Patterning involves lithography. In photolithography (such as 193 nm lithography), a pattern is printed by emitting photons from a photon source onto a mask to print the pattern onto a light-sensitive photoresist, which then triggers a chemical reaction in the photoresist that, after development, removes certain portions of the photoresist to form the pattern.

[0005] Advanced technology nodes (defined by the International Technology Roadmap for Semiconductors) include 22 nm, 16 nm, and beyond. For example, at the 16 nm node, a typical via or line width in a damascene structure is typically about 30 nm or less. The scaling of features in advanced semiconductor integrated circuits (ICs) and other devices is driving improvements in lithographic resolution.

[0006] Extreme ultraviolet (EUV) lithography extends lithography technology by moving to shorter imaging source wavelengths than can be achieved with other photolithography methods. EUV sources with wavelengths of approximately 10-20 nm or 11-14 nm (e.g., 13.5 nm wavelength) are available for modern lithography tools (also called scanners). EUV radiation is strongly absorbed by a wide range of solid and fluid materials, including quartz and water vapor, and is therefore applied in a vacuum. Summary of the Invention

[0007] The present disclosure relates to the use of one or more metal chelating agents during the development (e.g., wet development) of metal-based photoresists (PRs). During lithographic exposure of organometallic PRs, an interfacial region can exist between the lithographically exposed and unexposed regions. As discussed herein, this interfacial region can be characterized as a region of abrupt transition from the most exposed regions to the completely unexposed regions. Thus, in this interfacial region, the composition of the PR can contain various partial reaction products that differ from those present in the most exposed regions and the completely unexposed regions. Such reaction products can lead to roughness after wet development processing. Furthermore, this interfacial region can span a short distance (e.g., 1 or 2 nanometers), and the general composition within this interfacial region is approximately the composition required at the dose threshold of wet development.

[0008] In this interfacial region, weakly bound metal species may be present. As described herein, the present disclosure provides for the removal of such metal species using metal chelating agents, which may improve the resulting patterning quality, particularly with respect to line width roughness (LWR) and / or line edge roughness (LER).

[0009] Thus, in a first aspect, the disclosure features a method including providing a radiation-patterned film (e.g., an exposed film) having an interfacial region; and developing the radiation-patterned film in the presence of a metal chelator (e.g., or two or more different metal chelators), where the metal chelator is configured to bind to one or more radiation-exposed metal centers in the interfacial region. In some embodiments, the radiation-exposed metal centers are weakly bound metal species (e.g., characterized by one, two, or three metal-oxygen bonds). The interfacial region can be located between the radiation-exposed and non-radiation-exposed regions, or within the radiation-exposed region (e.g., between highly exposed and less-exposed regions). In some embodiments, the interfacial region comprises an interface or transition region located between the highly exposed and non-exposed regions, or between the highly exposed and less exposed regions.

[0010] In certain embodiments, the exposed or radiation-patterned film comprises an extreme ultraviolet (EUV)-sensitive film. In other embodiments, the exposed or radiation-patterned film is characterized by exposure to EUV radiation to have EUV-exposed regions, non-EUV-exposed regions, and an interface region disposed between the EUV-exposed and non-EUV-exposed regions. In yet other embodiments, the interface region comprises a region that is less exposed to EUV radiation (e.g., compared to a region that is highly exposed to EUV radiation). In certain embodiments, the interface region is within the EUV-exposed region.

[0011] In some embodiments, as used herein, a "radiation-exposed region" can include a region where exposure to radiation can vary. For example, the dose curve (function of distance) within the radiation-exposed region can be nonlinear, resulting in some regions within the radiation-exposed region being exposed to higher radiation doses and other regions within the radiation-exposed region being exposed to lower radiation doses. The extent of radiation dose can affect the extent of reaction within the PR, such that various reaction products can exist within the radiation-exposed region. Thus, in some embodiments, the radiation-exposed region can be considered to comprise an interface region with an abrupt transition from the most exposed region to the less exposed region.

[0012] In some embodiments, the developing step further includes removing the interfacial region. Such removal may provide improved line roughness (LWR) and / or line roughness (LER) compared to developing without a metal chelating agent (characterized by a reduction in high-frequency noise determined by power spectral density measurements to distinguish between different sources of line roughness, such as high-, mid-, and low-frequency sources). For example, the use of a chelating agent may reduce high- to mid-frequency roughness by removing local perturbations to the line shape of the power spectral density curve. In certain embodiments, the developing step includes providing a metal chelating agent with a solvent or solvent mixture (e.g., any of those described herein).

[0013] In other embodiments, the developing step further comprises utilizing a solvent or solvent mixture that preferentially removes radiation-exposed regions relative to non-radiation-exposed regions. In some embodiments, the metal chelator is soluble in the solvent or solvent mixture. In certain embodiments, the metal chelator preferentially binds to radiation-exposed metal centers in the interface regions relative to metal centers present in non-radiation-exposed regions.

[0014] In some embodiments, the metal chelator may be a dicarbonyl (e.g., 1,3-diketone), a diol, a carboxylic acid (e.g., R A1 -CO2H, where R A1is H, optionally substituted alkyl, optionally substituted hydroxyalkyl, optionally substituted hydroxyaryl, optionally substituted carboxyalkyl, optionally substituted carboxyaryl, or optionally substituted aryl), diacid, triacid, hydroxycarboxylic acid, hydroxamic acid (e.g., R A1 -C(O)NR A2 OH, where R A1 and R A2 wherein each is independently H, optionally substituted alkyl, or optionally substituted aryl), a hydroxylactone, a hydroxyketone (e.g., hydroxypyridinone, hydroxypyrimidone, or hydroxypyrone), or a salt thereof. In other embodiments, the metal chelator comprises formic acid, citric acid, acetylacetone, salicylic acid, catechol, or ascorbic acid.

[0015] In other embodiments, the metal chelator has the structure of Formula (I), (II), or (III): [ka] , [ka] , [ka] , or hydroxyketones with their salts, where X 1 and X 2 Each of these is independent and -CR 1 = or -N=, Each R 1 and R 2 are independently H, optionally substituted alkyl, optionally substituted hydroxyalkyl, optionally substituted carboxyalkyl, —C(O)NR N1 R N2, or -C(O)OR O1 where R N1 , R N2 , and ,R O1 are independently H, optionally substituted alkyl, or optionally substituted alkyl, and optionally R N1 and R N2 collectively form an optionally substituted heterocyclyl, R 3 are independently H, optionally substituted alkyl, or optionally substituted aryl.

[0016] In some embodiments, the metal chelator comprises a plurality of moieties disposed on a backbone, wherein the plurality of moieties are selected from hydroxyl, carboxyl, amido, amino, and oxo. Non-limiting moieties include one or more of a dicarbonyl, diol, carboxylic acid, diacid, triacid, hydroxycarboxylic acid, hydroxamic acid, hydroxylactone, hydroxyketone, or salts thereof in mono- or polyvalent form.

[0017] In some embodiments, the radiation-exposed metal center comprises a transition metal. Non-limiting metal centers include, for example, tin (Sn), tellurium (Te), bismuth (Bi), antimony (Sb), tantalum (Ta), cesium (Cs), indium (In), molybdenum (Mo), or hafnium (Hf).

[0018] The exposed or radiation-patterned film may be formed from any useful metal precursor (e.g., any of those described herein). In certain embodiments, the metal precursor comprises a structure having the following formula (IV): M a R b (IV), wherein M is a metal (e.g., any of those described herein, such as Sn, Te, Bi, Sb, Ta, Cs, In, Mo, or Hf), each R is independently H, halo, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted alkoxy, optionally substituted alkanoyloxy, optionally substituted aryl, optionally substituted amino, optionally substituted bis(trialkylsilyl)amino, optionally substituted trialkylsilyl, oxo, anionic ligand, neutral ligand, or polydentate ligand, and a≧1 (e.g., a is 1, 2, or 3), and b≧1 (e.g., b is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12).

[0019] In a second aspect, the present disclosure includes a method (e.g., a resist-based method) comprising depositing a metal precursor onto a surface of a substrate to provide a patterned radiation-sensitive film as a resist film, patterning the resist film by exposing it to patterning radiation, and developing the exposed film in the presence of a metal chelator and a solvent. In some embodiments, the depositing step includes the use of a counter-reactant (such as any of the oxygen-containing counter-reactants described herein).

[0020] In other embodiments, the patterning step provides an exposed film having one or more radiation-exposed regions, one or more non-radiation-exposed regions, and an interface region disposed between at least one of the radiation-exposed regions and at least one non-radiation-exposed region. In some embodiments, the radiation exposure (e.g., the patterning radiation exposure) comprises EUV exposure having a wavelength in the range of about 10 nm to about 20 nm in a vacuum atmosphere.

[0021] In further embodiments, the developing step removes the interfacial region and either the radiation-exposed or non-radiation-exposed regions, hi some embodiments, the pattern comprises reduced LER and / or LWR compared to a pattern developed without the metal chelator.

[0022] In some embodiments, the metal chelator is configured to preferentially remove the interfacial region (e.g., relative to the radiation-exposed and / or non-radiation-exposed regions), hi further embodiments, the solvent is configured to preferentially remove either the radiation-exposed or non-radiation-exposed regions (e.g., relative to the interfacial region).

[0023] In some embodiments, the method further comprises removing the metal chelator and / or metal-chelate complex from the film (eg, after development).

[0024] In a third aspect, the present disclosure includes an apparatus (e.g., an apparatus for forming a resist film) comprising a deposition module, a patterning module, a development module, one or more memory devices, one or more processors, and a controller with system control software encoded with instructions including machine-readable instructions.

[0025] In some embodiments, the deposition module includes a chamber for depositing a patterned radiation-sensitive film (e.g., an EUV-sensitive film). In other embodiments, the patterning module includes a photolithography tool having a radiation source with a wavelength of less than 300 nm (wherein the radiation source may be a radiation source with a wavelength of less than 30 nm). In yet other embodiments, the development module includes a chamber for developing a resist film.

[0026] In certain embodiments, the controller instructions include machine-readable instructions for depositing a metal precursor onto the upper surface of the semiconductor substrate (e.g., in a deposition module) to form a patterned radiation-sensitive film as a resist film. In other embodiments, the controller instructions include machine-readable instructions for patterning the resist film directly by patterning radiation exposure with a resolution of less than 300 nm (e.g., or less than 30 nm) to form an interface region disposed between at least one radiation-exposed region and at least one non-radiation-exposed region (e.g., compared to another region highly exposed to EUV radiation). In certain embodiments, the interface region is a region that is less exposed to EUV radiation (e.g., compared to another region highly exposed to EUV radiation), or a transition region disposed between at least one EUV-exposed region and at least one non-EUV-exposed region, or a transition region disposed between at least one highly EUV-exposed region and at least one less EUV-unexposed region.

[0027] In some embodiments, the controller instructions include machine-readable instructions for developing the exposed film in the presence of a metal chelator and a solvent (e.g., in a development module). In certain embodiments, developing removes the interfacial region and at least one of the radiation-exposed or non-radiation-exposed regions to provide a pattern in the resist film. In other embodiments, the machine-readable instructions include instructions for removing the interfacial region. In yet other embodiments, the machine-readable instructions include instructions for removing the EUV-exposed or non-EUV-exposed regions.

[0028] In any embodiment herein, the metal chelator may be a dicarbonyl (e.g., 1,3-diketone (acetylacetone, etc.)), a hydroxyalkyl, a hydroxyaryl, a diol (e.g., glycol, catechol, etc.), a carboxylic acid (e.g., formic acid or citric acid, etc. ...aryl, a diol (e.g., glycol, catechol, etc.), a carboxylic acid (e.g., formic acid or citric acid, etc.), a hydroxyaryl, a diol (e.g., glycol, catechol, etc.), a carboxylic acid (e.g., formic acid or citric acid, etc.), a hydroxyaryl, a diol (e.g., glycol, catechol, etc.), a A1 -CO2H, where R A1is H, optionally substituted alkyl, optionally substituted hydroxyalkyl, optionally substituted carboxyalkyl, optionally substituted aryl, or optionally substituted aryl), diacids, triacids, hydroxycarboxylic acids (e.g., phenolic acids (such as salicylic acid)), hydroxamic acids (e.g., R A1 -C(O)NR A2 OH, where R A1 and R A2 and each independently include H, optionally substituted alkyl, or optionally substituted aryl), hydroxylactone (e.g., ascorbic acid), hydroxyketone (e.g., hydroxypyridinone, hydroxypyrimidone, or hydroxypyrone, such as those having the structure of Formula (I), (II), or (III) described herein), or a salt thereof. In other embodiments, the metal chelator comprises multiple moieties disposed on the backbone, where the multiple moieties are selected from hydroxyl, carboxyl, amido, amino, and oxo. Non-limiting moieties include one or more of a dicarbonyl, diol, carboxylic acid, diacid, triacid, hydroxycarboxylic acid, hydroxamic acid, hydroxylactone, hydroxyketone in mono- or polyvalent form, or a salt thereof.

[0029] In any embodiment herein, the exposed or patterned radiation-sensitive film comprises a metal oxide film or an organometallic oxide film or an organometallic material.

[0030] In any embodiment herein, the exposed or patterned radiation sensitive film comprises an EUV sensitive film.

[0031] In any embodiment herein, the exposed or patterned radiation-sensitive film comprises a metal having a high patterning radiation absorption cross-section. In certain embodiments, the metal has a high EUV absorption cross-section. In other embodiments, the metal layer comprises tin (Sn), tellurium (Te), bismuth (Bi), antimony (Sb), tantalum (Ta), cesium (Cs), indium (In), molybdenum (Mo), or hafnium (Hf), and combinations thereof.

[0032] In any embodiment herein, the metal precursor comprises a structure having formula (IV), (V), (Va), (VI), (VII), (VIII), (IX), (X), or (XI) described herein.

[0033] In any embodiment herein, the vapor deposition process comprises providing or depositing a metal precursor in vapor form. In other embodiments, the vapor deposition process comprises providing a counter reactant in vapor form. In certain embodiments, the vapor deposition process comprises chemical vapor deposition (CVD), atomic layer deposition (ALD), or molecular layer deposition (MLD), as well as plasma-enhanced forms thereof.

[0034] In any embodiment herein, depositing a metal layer further comprises providing a counter reactant. Non-limiting counter reactants include oxygen-containing counter reactants such as O, O, water, peroxide, hydrogen peroxide, oxygen plasma, water plasma, alcohols, dihydroxy alcohols, polyhydroxy alcohols, fluorinated dihydroxy alcohols, fluorinated polyhydroxy alcohols, fluorinated glycols, formic acid, and other sources of hydroxyl moieties, as well as combinations thereof. Further details are provided below.

[0035] definition As used interchangeably herein, "acyloxy" or "alkanoyloxy" refers to an acyl group or an alkanoyl group, as defined herein, attached to the parent molecular group through an oxy group. In certain embodiments, the alkanoyloxy is -OC(O)-Ak, where Ak is an alkyl group, as defined herein. In some embodiments, the unsubstituted alkanoyloxy is C 2-7 It is an alkanoyl group. Examples of alkanoyl groups include acetoxy.

[0036] "Alkenyl" refers to an optionally substituted C alkyl group having one or more double bonds. 2-24 An alkenyl group is a cyclic (e.g., C 3-24 The alkenyl group may be substituted or unsubstituted. For example, the alkenyl group may be substituted with one or more of the substituents described herein for alkyl.

[0037] "Alkenylene" refers to a polyvalent (e.g., divalent) form of an alkenyl group, as defined herein. An alkenylene group can be substituted or unsubstituted. For example, an alkenylene group can be substituted with one or more substituents described herein for alkyl.

[0038] "Alkoxy" means -OR, where R is an optionally substituted alkyl group as described herein. Examples of alkoxy include methoxy, ethoxy, butoxy, trihaloalkoxy (such as trifluoromethoxy), and the like. Alkoxy groups can be substituted or unsubstituted. For example, an alkoxy group can be substituted with one or more substituents as described herein for alkyl. Examples of unsubstituted alkoxy groups are C 1-3 , C 1-6 , C 1-12 , C 1-16 , C 1-18 , C 1-20 , or C 1-24 Contains an alkoxy group.

[0039] The terms "alkyl" and the prefix "alk" refer to a branched or unbranched saturated hydrocarbon group of 1 to 24 carbon atoms, such as methyl (Me), ethyl (Et), n-propyl (n-Pr), isopropyl (i-Pr), cyclopropyl, n-butyl (n-Bu), isobutyl (i-Bu), s-butyl (s-Bu), t-butyl (t-Bu), cyclobutyl, n-pentyl, isopentyl, s-pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, eicosyl, tetracosyl, and the like. An alkyl group can be cyclic (e.g., C 3-24 The alkyl group may be branched or unbranched. The alkyl group may also be substituted or unsubstituted. For example, the alkyl group may include a haloalkyl, in which the alkyl group is substituted with one or more halo groups, as described herein. In another example, the alkyl group may be substituted with 1, 2, 3, or 4 (in the case of an alkyl group of 2 or more carbons) substituents independently selected from the following group: (1) C 1-6 Alkoxy (e.g., -O-Ak, where Ak is an optionally substituted C 1-6 alkyl), (2) amino (e.g., NR N1 R N2 , where R N1 and R N2 are independently H or optionally substituted alkyl, or R N1 and R N2 each together with the nitrogen atom to which it is attached forms a heterocyclyl group), (3) aryl, (4) arylalkoxy (e.g., -O-Lk-Ar, where Lk is a divalent form of an optionally substituted alkyl and Ar is an optionally substituted aryl), (5) aryloyl (e.g., -C(O)-Ar, where Ar is an optionally substituted aryl), (6) cyano (e.g., -CN), (7) carboxaldehyde (e.g., -C(O)H), (8) carboxyl (e.g., -COH), (9) C 3-8 Cycloalkyl (e.g., monovalent saturated or unsaturated non-aromatic cyclic C 3-8hydrocarbon group), (10) halo (e.g., F, Cl, Br, or I), (11) heterocyclyl (e.g., a five-, six-, or seven-membered ring containing one, two, three, or four non-carbon heteroatoms (such as nitrogen, oxygen, phosphorus, sulfur, or halo), unless otherwise specified), (12) heterocyclyloxy (e.g., -O-Het, where Het is heterocyclyl as described herein), (13) heterocyclyloyl (e.g., -C(O)-Het, where Het is heterocyclyl as described herein), (14) hydroxyl (e.g., -OH), (15) N-protected amino, (16) nitro (e.g., NO), (17) oxo (e.g., =O), (18) -COR A , where R A is (a)C 1-6 Alkyl, (b) C 4-18 aryl, and (c) (C 4-18 Aryl)C 1-6 alkyl (e.g., -Lk-Ar, where Lk is a divalent form of an optionally substituted alkyl group and Ar is an optionally substituted aryl), (19) -C(O)NR B R C , where R B and R C are independently (a) hydrogen, (b) C 1-6 Alkyl, (c) C 4-18 aryl, and (d) (C 4-18 Aryl)C 1-6 alkyl (e.g., -Lk-Ar, where Lk is a divalent form of an optionally substituted alkyl group and Ar is an optionally substituted aryl), and (20) -NR G R H , where R G and R H are independently (a) hydrogen, (b) an N-protecting group, or (c) C 1-6 Alkyl, (d) C 2-6 alkenyl (e.g., optionally substituted alkyl having one or more double bonds); (e) C 2-6alkynyl (e.g., optionally substituted alkyl having one or more triple bonds), (f) C 4-18 Aryl, (g) (C 4-18 Aryl)C 1-6 alkyl (e.g., Lk-Ar, where Lk is a divalent form of an optionally substituted alkyl group and Ar is an optionally substituted aryl); (h) C 3-8 cycloalkyl, and (i)(C 3-8 Cycloalkyl)C 1-6 and alkyl (e.g., -Lk-Cy, where Lk is a divalent form of an optionally substituted alkyl group and Cy is an optionally substituted cycloalkyl as described herein), and in one embodiment, no two groups are attached to the nitrogen atom through a carbonyl group. The alkyl group can be a primary, secondary, or tertiary alkyl group substituted with one or more substituents (e.g., one or more halo or alkoxy). In some embodiments, the unsubstituted alkyl group is selected from the group consisting of C 1-3 , C 1-6 , C 1-12 , C 1-16 , C 1-18 , C 1-20 , or C 1-24 It is an alkyl group.

[0040] "Alkylene" refers to the polyvalent (e.g., divalent) form of an alkyl group as described herein. Examples of alkylene groups include methylene, ethylene, propylene, butylene, and the like. In some embodiments, an alkylene group is a C 1-3 , C 1-6 , C 1-12 , C 1-16 , C 1-18 , C 1-20 , C 1-24 , C 2-3 , C 2-6 , C 2-12 , C 2-16 , C 2-18 , C 2-20 , or C 2-24It is an alkylene group. The alkylene group can be branched or unbranched. Also, the alkylene group can be substituted or unsubstituted. For example, the alkylene group can be substituted with one or more of the substituents described herein for alkyl.

[0041] "Alkynyl" refers to an optionally substituted C alkyl group having one or more triple bonds. 2-24 It refers to an alkyl group. Alkynyl groups can be cyclic or acyclic, and examples include ethynyl, 1-propynyl, and the like. Alkynyl groups can also be substituted or unsubstituted. For example, alkynyl groups can be substituted with one or more of the substituents described herein for alkyl.

[0042] "Alkynylene" refers to an optionally substituted C alkyl group having one or more triple bonds. 2-24 It refers to a polyvalent (e.g., divalent) form of an alkynyl group, which is an alkyl group. An alkynylene group can be cyclic or acyclic. An alkynylene group can be substituted or unsubstituted. For example, an alkynylene group can be substituted with one or more substituents described herein for alkyl. Non-limiting examples of alkenylene groups include -C≡C- or -C≡CCH2-.

[0043] "Amide" is -C(O)NR N1 R N2 where R N1 and R N2 are independently H or optionally substituted alkyl, or R N1 and R N2 together with the nitrogen atom to which each is attached form a heterocyclyl group as defined herein.

[0044] "Amino" is -NR N1 R N2 where R N1 and R N2 are independently H, optionally substituted alkyl, or optionally substituted aryl, or R N1 and RN2 together with the nitrogen atom to which each is attached form a heterocyclyl group as defined herein.

[0045] "Aryl" refers to a group containing any carbon-based aromatic group, including, but not limited to, phenyl, benzyl, anthracenyl, anthryl, benzocyclobutenyl, benzocyclooctenyl, biphenylyl, chrysenyl, dihydroindenyl, fluoranthenyl, indacenyl, indenyl, naphthyl, phenanthryl, phenoxybenzyl, picenyl, pyrenyl, terphenyl, and the like, including fused benzo-C (e.g., as defined herein) groups such as indanyl, tetrahydronaphthyl, fluorenyl, and the like. 4-8 It includes cycloalkyl radicals. The term aryl also includes heteroaryl, which is defined as a group containing an aromatic group with at least one heteroatom incorporated within the ring of the aromatic group. Examples of heteroatoms include, but are not limited to, nitrogen, oxygen, sulfur, and phosphorus. Similarly, the term non-heteroaryl (also included in the term aryl) defines a group containing an aromatic group that does not contain a heteroatom. Aryl groups can be substituted or unsubstituted. Aryl groups can be substituted with 1, 2, 3, 4, or 5 substituents, such as any of the substituents described herein for alkyl.

[0046] "Arylene" refers to a polyvalent (e.g., divalent) form of an aryl group described herein. Examples of arylene groups include phenylene, naphthylene, biphenylene, triphenylene, diphenyl ether, acenaphthenylene, anthrylene, or phenanthrylene. In some embodiments, an arylene group is C 4-18 , C 4-14 , C 4-12 , C 4-10 , C 6-18 , C 6-14 , C 6-12 , or C 6-10The arylene group is an arylene group. The arylene group can be branched or unbranched. The arylene group can also be substituted or unsubstituted. For example, the arylene group can be substituted with one or more of the substituents described herein for alkyl or aryl.

[0047] "Carbonyl" means the group -C(O)-, which may also be represented as >C=O.

[0048] "Carboxyl" means a -CO2H group.

[0049] "Carboxyalkyl" means an alkyl group, as defined herein, substituted with one or more carboxyl groups, as defined herein.

[0050] "Carboxyaryl" means an aryl group, as defined herein, substituted with one or more carboxyl groups, as defined herein.

[0051] "Carboxylic acid" means any moiety or compound containing one or more carboxyl groups. Non-limiting examples of carboxylic acids include carboxyalkyl or carboxyaryl. As used herein, "diacid" refers to a carboxylic acid having two carboxyl groups, and "triacid" refers to a carboxylic acid having three carboxyl groups.

[0052] "Cycloalkenyl," unless otherwise specified, refers to a monovalent unsaturated non-aromatic or aromatic cyclic hydrocarbon group of 3 to 8 carbon atoms having one or more double bonds. Cycloalkenyl groups can be substituted or unsubstituted. For example, cycloalkenyl groups can be substituted with one or more substituents, including those described herein for alkyl.

[0053] "Cycloalkyl," unless otherwise specified, means a monovalent saturated or unsaturated non-aromatic or aromatic cyclic hydrocarbon radical of 3 to 8 carbon atoms, e.g., cyclopropyl, cyclobutyl, cyclopentyl, cyclopentadienyl, cyclohexyl, cycloheptyl, bicyclo[2.2.1.]heptyl, and the like. Cycloalkyl groups can also be substituted or unsubstituted. For example, cycloalkyl groups can be substituted with one or more substituents, including those described herein for alkyl.

[0054] "Dicarbonyl" means any moiety or compound containing two carbonyl groups, as defined herein. Non-limiting dicarbonyl moieties include 1,2-dicarbonyl (e.g., R C1 -C(O)-C(O)R C2 , where R C1 and R C2 each independently represents an optionally substituted alkyl, halo, optionally substituted alkoxy, hydroxyl, or leaving group), 1,3-dicarbonyl, or 1,3-diketone (e.g., R C1 -C(O)-C(R 1a R 2a )-C(O)R C2 , where R C1 and R C2 are each independently an optionally substituted alkyl, halo, optionally substituted alkoxy, hydroxyl, or a leaving group, and R 1a and R 2a are independently selected from H or an optional substituent provided for alkyl as defined herein), and 1,4-dicarbonyl (e.g., R C1 -C(O)-C(R 1a R 2a )-C(R 3a R 4a )-C(O)R C2 , where R C1 and R C2 are each independently an optionally substituted alkyl, halo, optionally substituted alkoxy, hydroxyl, or a leaving group, and R 1a , R2a , R 3a , and ,R 4a each independently includes H, or an optional substituent provided for alkyl as defined herein.

[0055] "Diol" means a hydroxyalkyl or hydroxyaryl, as defined herein, containing a hydroxyl group.

[0056] "Halo" means F, Cl, Br, or I.

[0057] "Haloalkyl" means an alkyl group, as defined herein, that is substituted with one or more halo.

[0058] "Heteroalkenylene" means a divalent form of an alkenylene group, as defined herein, containing one, two, three, or four non-carbon heteroatoms (e.g., atoms independently selected from the group consisting of nitrogen, oxygen, phosphorus, sulfur, selenium, or halo). Heteroalkenylene groups can be substituted or unsubstituted. For example, heteroalkenylene groups can be substituted with one or more substituents described herein for alkyl. Non-limiting heteroalkenylene groups include, for example, -NR N1 -Ak-, -Ak-NR N1 -, -O-Ak-, or -Ak-O-, where Ak is optionally substituted alkenylene as defined herein.

[0059] "Heteroalkylene" refers to a divalent form of an alkylene group, as defined herein, containing one, two, three, or four non-carbon heteroatoms (e.g., atoms independently selected from the group consisting of nitrogen, oxygen, phosphorus, sulfur, selenium, or halo). Heteroalkylene groups can be substituted or unsubstituted. For example, heteroalkylene groups can be substituted with one or more substituents described herein for alkyl. Non-limiting heteroalkylene groups include, for example, -NR N1 -Ak-, -Ak-NR N1The groups include -, -O-Ak-, or -Ak-O-, where Ak is optionally substituted alkylene as defined herein.

[0060] "Heterocyclyl," unless otherwise specified, refers to a three-, four-, five-, six-, or seven-membered ring (e.g., a five-, six-, or seven-membered ring) containing one, two, three, or four non-carbon heteroatoms (e.g., atoms independently selected from the group consisting of nitrogen, oxygen, phosphorus, sulfur, selenium, or halo). Three-membered rings have zero to one double bond; four- and five-membered rings have zero to two double bonds; and six- and seven-membered rings have zero to three double bonds. The term "heterocyclyl" also includes bicyclic, tricyclic, and tetracyclic groups in which any of the above heterocycles is fused to one, two, or three rings independently selected from the group consisting of an aryl ring, a cyclohexane ring, a cyclohexene ring, a cyclopentane ring, a cyclopentene ring, and another monocyclic heterocycle (e.g., indolyl, quinolyl, isoquinolyl, tetrahydroquinolyl, benzofuryl, benzothienyl, etc.). Heterocycles include acridinyl, adenyl, alloxazinyl, azaadamantanyl, azabenzimidazolyl, azabicyclononyl, azacycloheptyl, azacyclooctyl, azacyclononyl, azahypoxanthinyl, azaindolyl, azecinyl, azepanyl, azepinyl, azetidinyl, azetyl, aziridinyl, azirinyl, azocanyl, azocinyl, azonanyl, benzimidazolyl, benzisothiazolyl, benzisoxazolyl, benzodiazepinyl, benzodiazocinyl, benzodihydrofuryl, benzodioxepinyl, benzodioxinyl, benzodioxolyl, benzodithiepinyl, benzodithiinyl, benzodithioxocinyl, benzofuranyl, benzophenazinyl, benzopyranonyl, benzopyranyl, benzopyrenyl, benzopyronyl, benzoquinolinyl, benzoquinolizinyl, benzothiadiazepinyl, benzothiadiazolyl, benzothiazepinyl, benzothiazocinyl, benzothiazolyl, benzothienyl, benzothiophenyl, benzothiazinonyl, benzothiazinyl, benzothiopyranyl, benzothiopyronyl, benzotriazepinyl, benzotriazinonyl, benzotriazinyl, benzotriazolyl, benzoxathiinyl, benzotrioxepinyl, benzoxadiazepinyl, benzoxathiazepinyl, benzoxathiepinyl,benzoxathiocinyl, benzoxazepinyl, benzoxazinyl, benzoxazocinyl, benzoxazolinonyl, benzoxazolinyl, benzoxazolyl, benzylsultamyl, benzylsultimyl, bipyrazinyl, bipyridinyl, carbazolyl (e.g., 4H-carbazolyl), carbolinyl (e.g., β-carbolinyl), chromanonyl, chromanyl, chromenyl, cinnolinyl, coumarinyl, cytodinyl, cytosinyl, decahydroisoquinolinyl, decahydroquinolinyl, diazabicyclooctyl, diazetyl, diaziridinethionyl, Diaziridinonyl, diaziridinyl, diazirinyl, dibenzisoquinolinyl, dibenzoacridinyl, dibenzocarbazolyl, dibenzofuranyl, dibenzophenazinyl, dibenzopyranonyl, dibenzopyronyl (xanthonyl), dibenzoquinoxalinyl, dibenzothiazepinyl, dibenzothiepinyl, dibenzothiophenyl, dibenzooxepinyl, dihydroazepinyl, dihydroazetyl, dihydrofuranyl, dihydrofuryl, dihydroisoquinolinyl, dihydropyranyl, dihydropyridinyl, dihydropyridyl, dihydroquinolinyl, dihydro thienyl, dihydroindolyl, dioxanyl, dioxazinyl, dioxindolyl, dioxiranyl, dioxenyl, dioxinyl, dioxobenzofuranyl, dioxolyl, dioxotetrahydrofuranyl, dioxothiomorpholinyl, dithianyl, dithiazolyl, dithienyl, dithiinyl, furanyl, furazanyl, furoyl, furyl, guaninyl, homopiperazinyl, homopiperidinyl, hypoxanthinyl, hydantoinyl, imidazolidinyl, imidazolinyl, imidazolyl, indazolyl (e.g., 1H-indazolyl), indolenyl, indolinyl, indolizinyl, indolyl (e.g., 1H-indolyl or 3H-indolyl), isatinyl, isobenzofuranyl, isochromanyl, isochromenyl, isoindazolyl, isoindolinyl, isoindolyl, isopyrazolonyl, isopyrazolyl, isoxazolidinyl, isoxazolyl, isoquinolinyl, isoquinolinyl, isothiazolidinyl, isothiazolyl, morpholinyl, naphthindazolyl, naphthindolyl, naphthyridinyl, naphthopyranyl, naphthothiazolyl, naphthothioxolyl, naphthotriazolyl,Naphthoxindolyl, naphthyridinyl, octahydroisoquinolinyl, oxabicycloheptyl, oxauracil, oxadiazolyl, oxazinyl, oxaziridinyl, oxazolidinyl, oxazolidonyl, oxazolinyl, oxazolonyl, oxazolyl, oxepanyl, oxetanoyl, oxetanyl, oxetyl, oxtenyl, oxindolyl, oxiranyl, oxobenzisothiazolyl, oxochromenyl, oxisosoquinolinyl, oxoquinolinyl, oxothiolanyl, phenanthridinyl, phenanthrolinyl, phenaz ... Enothiazinyl, phenothienyl (benzothiofuranyl), phenoxathiinyl, phenoxazinyl, phthalazinyl, phthalazonyl, phthalidyl, phthalimidinyl, piperazinyl, piperidinyl, piperidonyl (e.g., 4-piperidonyl), pteridinyl, purinyl, pyranyl, pyrazinyl, pyrazolidinyl, pyrazolinyl, pyrazolopyrimidinyl, pyrazolyl, pyridazinyl, pyridinyl, pyridopyrazinyl, pyridopyrimidinyl, pyridyl, pyrimidinyl, pyrimidyl, pyrronyl, pyrrolidinyl, pyrrolidonyl (e.g., 2-pyrrolidonyl) , pyrrolinyl, pyrrolidinyl, pyrrolyl (e.g., 2H-pyrrolyl), pyrylium, quinazolinyl, quinolinyl, quinolizinyl (e.g., 4H-quinolizinyl), quinoxalinyl, quinuclidinyl, selenazinyl, selenazolyl, selenophenyl, succinimidyl, sulfonyl, tetrahydrofuranyl, tetrahydrofuryl, tetrahydroisoquinolinyl, tetrahydroisoquinolyl, tetrahydropyridinyl, tetrahydropyridyl (piperidyl), tetrahydropyranyl, tetrahydropyronyl, tetrahydroquinolinyl, tetrahydroquinolyl thiazinyl, tetrahydrothienyl, tetrahydrothiophenyl, tetrazinyl, tetrazolyl, thiadiazinyl (e.g., 6H-1,2,5-thiadiazinyl or 2H,6H-1,5,2-dithiazinyl), thiadiazolyl, thianthrenyl, thianyl, thianaphthenyl, thiazepinyl, thiazinyl, thiazolidinedionyl, thiazolidinyl, thiazolyl, thienyl, thiepanyl, thiepinyl, thietanyl, thiethyl, thiiranyl, thiocanyl, thiochromanonyl, thiochromanyl, thiochromenyl, thiodiazinyl, thiodiazolyl, thioindoxyl,Heterocyclyl groups include thiomorpholinyl, thiophenyl, thiopyranyl, thiopyronyl, thiotriazolyl, thiourazolyl, thioxanyl, thioxolyl, thymidinyl, thyminyl, triazinyl, triazolyl, trithianyl, urazinyl, urazolyl, uretidinyl, uretinyl, urisyl, uridinyl, xanthenyl, xanthinyl, xantthionyl, and the like, as well as variations thereof (e.g., containing one or more oxo and / or amino groups), and salts thereof. Heterocyclyl groups can be substituted or unsubstituted. For example, heterocyclyl groups can be substituted with one or more of the substituents described herein for alkyl.

[0061] "Hydroxamic acid" refers to a carboxylic acid, as defined herein, in which the hydroxyl group is replaced by a hydroxyamino group. Non-limiting hydroxamic acids include those in which R A1 -C(O)NR A2 OH, where R A1 and R A2 Each of is independently H, optionally substituted alkyl, or optionally substituted aryl.

[0062] "Hydroxyl" means --OH.

[0063] "Hydroxyalkyl" means an alkyl group, as defined herein, substituted with one to three hydroxyl groups, provided that only one hydroxyl group may be attached to a carbon atom of the alkyl group, and examples include hydroxymethyl, dihydroxypropyl, and the like.

[0064] "Hydroxyaryl" means an aryl group, as defined herein, substituted with one to three hydroxyl groups, provided that only one hydroxyl group may be attached to a carbon atom of the aryl group, and is exemplified by hydroxyphenyl, dihydroxyphenyl, and the like.

[0065] By "hydroxycarboxylic acid" is meant any moiety or compound having at least one hydroxyl group and at least one carboxyl group.

[0066] A "hydroxyketone" is any moiety or compound having a carbonyl group and a hydroxyl group as substituents. In certain instances, the carbonyl group can form a ketone or an amide. Non-limiting hydroxyketones include those having R A1 -C(O)-R A2 where R A1 and R A2 each is an optionally substituted alkylene, an optionally substituted alkenylene, an optionally substituted heteroalkylene, or an optionally substituted heteroalkenylene, and R A1 and R A2 at least one of R contains a hydroxyl substituent; A1 and R A2 taken together form a cyclic group (eg, heterocyclyl as defined herein).

[0067] "Hydroxylactone" refers to a cyclic ester having one or more hydroxyl groups. Non-limiting examples of hydroxylactones include R A1 -C(O)-OR A2 wherein each of RA1 and RA2 is optionally substituted alkylene or optionally substituted alkenylene, and R A1 and R A2 at least one of R contains a hydroxyl substituent; A1 and R A2 taken together form a cyclic group (eg, heterocyclyl as defined herein).

[0068] "Oxo" means the radical =O.

[0069] As used herein, the terms "top," "bottom," "upper," "lower," "above," and "below" are used to indicate relative relationships between structures. Use of these terms does not indicate or require that a particular structure be located in a particular position on the device.

[0070] Other features and advantages of the invention will become apparent from the following description and claims. [Brief explanation of the drawings]

[0071] [Figure 1] Schematic diagram showing a non-limiting method for patterning and developing a film.

[0072] [Figure 2A] Schematic showing a non-limiting method for patterning a film and developing in the presence of a chelating agent. [Figure 2B] Schematic showing a non-limiting method for patterning a film and developing in the presence of a chelating agent.

[0073] [Figure 3A] Schematic diagram showing a non-limiting method of utilizing a metal precursor during deposition and a chelating agent during development. [Figure 3B] Schematic diagrams illustrating non-limiting methods utilizing metal precursors during deposition and chelating agents during development: (A) A first method 300 for providing either a positive tone resist (path i) or a negative tone resist (path ii), as well as (B) a block diagram of an example method 350 are provided.

[0074] [Figure 4] 5 is a schematic diagram illustrating an embodiment of a multi-station processing tool 500. FIG.

[0075] [Figure 5] 6 is a schematic diagram illustrating an embodiment of an inductively coupled plasma device 600. FIG.

[0076] [Figure 6] 7 is a schematic diagram illustrating one embodiment of a semiconductor processing cluster tool architecture 700. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0077] The present disclosure generally relates to the field of semiconductor processing. In particular, the present disclosure is directed to utilizing one or more metal chelators during development. For example, metal chelators can strongly bind metal ions and selectively remove weakly bound metals (which may be present at the rough interface between exposed and unexposed PR regions). Such metal chelators thereby provide a tuning knob for manipulating LER / LWR by manipulating the concentration and / or chemical identity of the chelator. While not wishing to be limited by mechanism, metal chelators bind metals at a rate that depends on the amount of steric hindrance and the physical size of the chelator molecule, while binding metal ions more strongly or weakly depending on the thermodynamic gain resulting from chemical bond formation. As a result, careful selection of the concentration and chemical identity of the chelator can provide a tuning knob for directly manipulating roughness at the interface between exposed and unexposed regions.

[0078] Without metal chelators, optimizing the solvent for wet development balances LER with optimizing the solubility difference between exposed and unexposed regions. However, utilizing a soluble metal chelator in the wet developer allows for a solvent optimized for contrast between only exposed and unexposed regions while directly addressing this interfacial roughness. The orthogonality between solvent selection and the interfacial improvement provided by the metal chelator allows for optimization of the developer contrast between exposed and unexposed regions while also optimizing LER due to the roughness at the interface between exposed and unexposed regions, which can be difficult to control without the metal chelator.

[0079] Reference will now be made in detail to specific embodiments of the present disclosure. Examples of specific embodiments are illustrated in the accompanying drawings. While the present disclosure has been described in connection with these specific embodiments, it should be understood that it is not intended to limit the disclosure to such specific embodiments. On the contrary, it is intended to cover alternatives, modifications, and equivalents that may be included within the spirit and scope of the present disclosure. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. The present disclosure may be practiced without some or all of these specific details. Additionally, detailed descriptions of well-known process operations have been omitted to avoid unnecessarily obscuring the present disclosure.

[0080] EUV lithography utilizes a patterned EUV resist to form a mask for use in etching an underlying layer. The EUV resist may be a polymeric chemically amplified resist (CAR) produced by a liquid-based spin-on technique. An alternative to CAR is a directly photopatternable metal oxide-containing film (such as those manufactured by Inpria, Inc., Corvallis, Oregon), as described, for example, in U.S. Patent Publication Nos. US2017 / 0102612, US2016 / 0216606, and US2016 / 0116839, which are incorporated herein by reference for their disclosure at least regarding photopatternable metal oxide-containing films. Such films may be formed by spin-on techniques or dry-deposited. Metal oxide-containing films can be patterned directly (i.e., without utilizing a separate photoresist) by EUV exposure in a vacuum atmosphere to provide patterning resolution of less than 30 nm, as described, for example, in U.S. Pat. No. 9,996,004, entitled "EUV PHOTOPATTERNING OF VAPOR-DEPOSITED METAL OXIDE-CONTAINING HARD MASKS," issued June 12, 2018, and / or International Application No. PCT / US19 / 31618, entitled "METHODS FOR MAKING EUV PATTERNABLE HARD MASKS," filed May 9, 2019, and published as International Publication No. WO2019 / 217749, the disclosures of which, at least, relate to the composition, deposition, and patterning of directly photopatternable metal oxide films to form EUV resist masks, which are incorporated herein by reference. Generally, patterning involves exposing the EUV resist to EUV radiation to form a photopattern in the resist, followed by development to remove portions of the resist according to the photopattern to form a mask.

[0081] Directly photopatternable EUV or DUV resists may be composed of or include metals and / or metal oxides mixed within an organic component. Metals / metal oxides hold great promise in that they may enhance EUV or DUV photon adsorption, generate secondary electrons, and / or exhibit high etch selectivity relative to underlying film stacks and device layers.

[0082] In general, resists can be utilized as positive or negative tone resists by controlling the resist chemistry and / or the solubility or reactivity of the developer. It would be beneficial to have an EUV or DUV resist that can function as either a negative or positive tone resist, and this disclosure includes utilization and development of films as either a negative or positive tone resist.

[0083] Method using metal chelating agents The present disclosure generally includes any useful method utilizing the metal chelators described herein, which may include any useful lithography process, deposition process, radiation exposure process, development process, and post-application process described herein.

[0084] While the following describes techniques related to EUV processing, such techniques may also be applicable to other next-generation lithography technologies. A variety of radiation sources may be used, including EUV (typically around 13.5 nm), DUV (deep UV, typically in the 248 nm or 193 nm range with excimer laser sources), X-ray (including EUV in the low energy range of the X-ray range), and e-beam (including a wide energy range).

[0085] After lithographic exposure to EUV radiation, both EUV-exposed and EUV-unexposed regions exist in the PR film. As seen in FIG. 1 , an EUV-sensitive film 112 can be disposed on the top surface of a substrate 111. The film 112 can be exposed 101 to EUV radiation to provide EUV-exposed regions 112b and EUV-unexposed regions 112c. In the PR film, radiation exposure can be used to generate activated reactive centers, which can then promote reactions that destabilize or stabilize the film to provide a positive-tone or negative-tone resist, respectively. For example, in a negative-tone metal-containing resist film, the exposed regions can contain EUV-activated reactive centers, which promote crosslinking and stabilization of the film. After development of such a resist, the exposed portions are retained, while the unexposed regions are removed by dissolution of the less stable regions of the film.

[0086] Between these exposed and unexposed regions, there is an interface region where the region of PR abruptly transitions from the most exposed to the completely unexposed. As can be seen, the exposed film can be characterized by an interface region 112a located between the exposed / unexposed regions. At such an interface region, the film is exposed to EUV and may therefore provide EUV-exposed reaction centers. However, the reaction may not proceed to completion, providing completely unreacted or unreacted regions.

[0087] Development of such interfacial regions remains challenging if the developer relies on the completion of such EUV-mediated reactions. As seen in Figure 1, when an exposed film is developed 102 with such a developer, the resulting pattern includes not only the exposed regions 112b but also the interfacial regions 112a. The presence of the interfacial regions can reduce the fidelity of the pattern in the film and contribute to increased roughness (e.g., increased LER and / or LWR).

[0088] The interfacial region can be removed by using a metal chelator that can target the unreacted or partially reacted PR region. As seen in FIG. 2A , a non-limiting method can include exposing 201 a film 212 disposed on a substrate to EUV radiation to provide an interfacial region 212a, an EUV-exposed region 212b, and an EUV-unexposed region 212c. Within the EUV-exposed region 212b, the PR is crosslinked to form metal-oxygen (MO) and metal-oxygen-metal (MOM) bonds and release ligands from the film. As described herein, such EUV-exposed region can also contain unreacted PR. Within the EUV-unexposed region 212c, the PR retains the original chemical structure of the metal precursor, where the EUV-cleavable labile ligand is generally retained. Non-limiting EUV-cleavable labile ligands include any of those described herein, such as R in formula (IV) or (V).

[0089] Within the interfacial region 212a, various chemical species are observed, with metal centers exhibiting some cross-linking with the MOM phase, some retention of labile ligands, and some formation of M-OH intermediates. Within this region, weakly bound metal species can be removed using metal chelating agents. In some instances, chelating agents can be selected to preferentially bind 255 EUV-exposed weakly bound metal species relative to the binding 250 of EUV-exposed cross-linked metal species. After developing 202 the exposed film with such chelating agents, the developed film can contain a pattern including exposed regions 212b (FIG. 2B).

[0090] In certain examples, the metal chelating agent is a charge-neutral chelating agent that binds metal ions (e.g., with various binding strengths) while keeping the resulting metal-chelate complex soluble and stable in the developer solvent (e.g., organic solvent). Thus, the metal chelating agent can be an organically soluble metal chelating agent used in a wet developer to seek out weakly bound metal ions in the interfacial region and bind such metal ions to form metal-chelate complexes. If the metal-chelate complex remains soluble in the developer, it can be removed from the wafer when the remainder of the wet developer is removed. Non-limiting chelating agents include derivatives of acetylacetone, formic acid, and hydroxypyridinone, as well as others described herein.

[0091] The choice of chelating agent can depend on any useful chemical and physical properties. In one example, a chelating agent is selected for its metal binding strength, which can be used to tailor how aggressively the interface between exposed and unexposed regions is affected by the presence of the chelating agent. Non-limiting determinations of metal binding strength can include a stability constant (e.g., log K or log β) between about 5 and about 50. In another example, the physical size of the chelating agent (e.g., between about 0.1 nm and about 10 nm) can be manipulated by adding a polymer backbone and used to tailor which size (e.g., critical dimension ≥ 10 nm) or shape (e.g., flat) of features are affected by the use of the metal chelating agent.

[0092] The presence of a metal chelating agent during wet development can provide an additional tuning knob for improving the LER of the developed PR pattern. Using different organic-soluble metal chelating agents, a particular organometallic process can have an optimized LER by selecting an appropriate chelating agent with sufficient binding strength to eliminate various types of rough spots in the PR at the interface between exposed and unexposed regions. Such chelating agent-solvent combinations can be optimized by the chemical type of each compound and the specific concentration of the chelating agent in the solvent or solvent mixture.

[0093] In addition to facilitating the removal of metal species, the use of such chelating agents can facilitate the removal of volatile compounds generated by or within the PR membrane. Non-limiting volatile compounds include carbon dioxide, carbon monoxide, alkenes, aromatics, and multi-alkyltin species that may be present within the membrane. Non-limiting species include SnR x L y where each R is independently an optionally substituted alkyl, each L is independently a dialkylamino (e.g., -NMe2), a hydroxyl, a bridging oxide, or another ligand, and 4≧x≧1, 3≧y≧0.

[0094] In this way, volatile compounds that could otherwise outgas and contaminate facilities and equipment can be solubilized as complexes in the solvent. Additionally, chelating agents may be used to remove poorly soluble chemical by-products that are generated during EUV exposure and can deposit on the surface of lithographically patterned PR.

[0095] The removal of the interfacial region and the presence of chelate complexes can be characterized by any useful method. For example, dissolution of metal centers by chelating agents can be detected by measuring the presence of metal chelate complexes in the developer solution. Non-limiting detection methods include the use of nuclear magnetic resonance (NMR) spectroscopy, liquid chromatography-mass spectrometry (LC-MS), high performance liquid chromatography (HPLC), and the like.

[0096] FIG. 3A provides an example method 300 comprising step 301 of depositing a film 312 on an upper surface of a substrate 311. The method may further comprise steps for treating the deposited EUV-sensitive film. Such steps are not necessary for the production of the film, but may be useful if the film is to be used as a photoresist. Accordingly, method 300 further comprises patterning the film by EUV exposure 302 to provide an exposed film having EUV-exposed and non-EUV-exposed regions 312b and 312c, respectively, and an interface region disposed therebetween. The patterning may include utilizing a mask 314 having EUV-transparent and EUV-opaque regions, where an EUV beam 315 is transmitted to film 312 through the EUV-transparent regions. The EUV exposure may include, for example, exposure having a wavelength in a range of about 10 nm to about 20 nm in a vacuum atmosphere (e.g., about 13.5 nm in a vacuum atmosphere).

[0097] Once the pattern is provided, method 300 may include developing 303 in the presence of one or more metal chelators to (i) remove the EUV-exposed regions to provide a pattern in a positive-tone resist film or (ii) remove the EUV-unexposed regions to provide a pattern in a negative-tone resist film. As described herein, an interface region may exist between the EUV-exposed and unexposed regions. Thus, in one embodiment, following path (i) in FIG. 3A selectively removes EUV-exposed region 312B and the interface region, which may be facilitated by using a metal chelator to bind to weakly bonded metal species formed after EUV exposure. Alternatively, following path (ii) in FIG. 3A , EUV-exposed region 312b and the interface region are maintained, which may be facilitated by a metal chelator to bind to weakly bonded metal species present in the unexposed region compared to metal species (e.g., bridged metal or bridged metal-organic material) present in the EUV-exposed region.

[0098] The development step may involve the use of liquid phase aqueous or organic solvents (e.g., as metal chelating agents). Additional development processing conditions are described herein.

[0099] Optional steps may be performed to further condition, modify, or treat the EUV-sensitive film, substrate, photoresist layer, capping layer, and / or any method herein. Figure 3B provides a flowchart of an example method 350 having various operations, including optional operations. As can be seen, in operation 352, a film is deposited using a metal precursor.

[0100] In optional operation 354, the backside or bevel of the substrate may be cleaned and / or the edge bead of photoresist deposited in a previous step may be removed. Such cleaning or removal steps may be useful to remove particles that may be present after depositing a photoresist layer. The removal step may include treating the wafer with a wet metal oxide (MeOx) edge bead removal (EBR) step.

[0101] In another example, the method may include optional operation 356 of performing a post-apply bake (PAB) of the deposited photoresist layer to remove residual moisture from the layer to form a film or to pretreat the photoresist layer in any useful manner. The optional PAB may be performed after film deposition and before EUV exposure, and may include a combination of thermal treatment, chemical exposure, and wetting to increase the EUV sensitivity of the film, thereby reducing the EUV dose required to develop a pattern in the film. In certain embodiments, the PAB step is performed at a temperature greater than about 100°C, or between about 100°C and about 200°C, or between about 100°C and about 250°C. In some examples, no PAB is performed in the method. In other examples, the PAB step is performed at a temperature less than about 180°C, less than about 200°C, or less than about 250°C.

[0102] In operation 358, the film is exposed to EUV radiation to develop a pattern. Generally, the EUV exposure changes the chemical composition of the film to create an etch selectivity contrast that can be utilized to remove portions of the film. Such contrast can provide a positive tone resist or a negative tone resist, as described herein.

[0103] Operation 360 is an optional post-exposure bake (PEB) of the exposed film to further remove residual moisture, promote chemical concentration within the film, or enhance the etch selectivity contrast of the exposed film, or to post-treat the film in any useful manner. Non-limiting examples of PEB temperatures include, for example, about 90°C to 600°C, 100°C to 400°C, 125°C to 300°C, 170°C to 250°C or higher, 190°C to 240°C, and other temperatures described herein. In other examples, the PEB step is performed at a temperature below about 180°C, below about 200°C, or below about 250°C.

[0104] In one example, the exposed film may be thermally treated (e.g., optionally in the presence of various chemical species) to promote reactivity within the EUV-exposed portions of the resist upon exposure to a stripper (e.g., a halide-based etchant such as HCl, HBr, H2, Cl2, Br2, BCl3, or combinations thereof, an aqueous alkaline developer, or an organic developer) or a positive-tone developer. In another example, the exposed film may be thermally treated to further crosslink ligands within the EUV-exposed portions of the resist, thereby providing non-EUV-exposed portions that can be selectively removed upon exposure to a stripper (e.g., a negative-tone developer).

[0105] Next, in operation 362, the PR pattern is developed in the presence of one or more metal chelating agents. In various embodiments of development, exposed areas are removed (positive tone) or unexposed areas are removed (negative tone). In various embodiments, these steps may be wet processes that include such metal chelating agents.

[0106] In another example, the method can include curing the patterned film (e.g., after development), thereby providing a resist mask disposed on the upper surface of the substrate. The curing step can include any useful treatment for further crosslinking or reacting the EUV-unexposed or EUV-exposed regions (e.g., exposure to plasma (e.g., O2, Ar, He, or CO2 plasma), exposure to ultraviolet light, annealing (e.g., at a temperature of about 180°C to about 240°C), thermal baking, or a combination thereof that can be useful for a post-development bake (PDB) step). In other examples, the PDB step is performed at a temperature below about 180°C, below about 200°C, or below about 250°C. Additional post-application treatments are described herein and may be performed as optional steps for any of the methods described herein.

[0107] Any useful type of chemical can be used during the deposition, patterning, stripping, and / or development steps. Such steps can be based on dry processes using gas-phase chemicals or wet processes using liquid-phase chemicals. As an example, a spin-on EUV photoresist (wet process), such as that available from Inpria, can be combined with other wet or dry processes described herein. In various embodiments, wafer cleaning can be a wet process described herein. In yet other embodiments, a wet development process can be used in combination with a spin-on EUV photoresist or a dry-deposited EUV photoresist.

[0108] Metal chelating agents Metal chelators can include any ligand capable of binding to a metal center (e.g., a transition metal center). Non-limiting ligands include ligands having a hydroxyl moiety, a carboxyl moiety, an amide moiety, an amino moiety, and / or an oxo moiety. Metal chelators can be any useful compound having such a ligand, and the compounds can include polymers, dicarbonyls (e.g., diketones), ketones, hydroxyketones (e.g., hydroxypyridinones, hydroxypyrimidones, or hydroxypyrones), alcohols (e.g., diols, triols, etc.), acids (e.g., carboxylic acids, diacids, triacids, hydroxycarboxylic acids, etc.), hydroxy acids (hydroxycarboxylic acids), amides, hydroxyamides, hydroxamic acids, lactones, hydroxylactones (e.g., ascorbic acid), and substituted forms thereof. Still other non-limiting metal chelating agents (e.g., wet forms of dry metal chelating agents) may be any chelating agent described in U.S. Provisional Patent Application No. 63 / 199,129, filed December 8, 2020, entitled "PHOTORESIST DEVELOPMENT WITH ORGANIC VAPOR," which application is incorporated herein by reference.

[0109] In other embodiments, the metal chelator is or includes a dicarbonyl. Non-limiting dicarbonyls include 1,3-diketones (e.g., R A1 -C(O)-C(R 1a R 2a )-C(O)R A2 where R A1 and R A2 are independently optionally substituted alkyl, optionally substituted haloalkyl, optionally substituted alkoxy, hydroxyl, optionally substituted aryl, or a leaving group, or optionally R A1 and R A2 collectively form a cyclic group (e.g., an optionally substituted cycloalkyl or an optionally substituted heterocyclyl), and R 1a and R 2aare independently H or an optional substituent provided for alkyl as defined herein. Particular dicarbonyls include acetylacetone.

[0110] In some embodiments, the metal chelator is or comprises an alcohol. Non-limiting alcohols include R A1 -OH and R A1 is optionally substituted alkyl, optionally substituted hydroxyalkyl, optionally substituted hydroxyaryl, optionally substituted carboxyalkyl, optionally substituted carboxyaryl, or optionally substituted aryl. Non-limiting alcohols include catechol and glycol.

[0111] In other embodiments, the metal chelator is or comprises a carboxylic acid. Non-limiting carboxylic acids include R A1 -CO2H, R A1 is H, optionally substituted alkyl, optionally substituted hydroxyalkyl, optionally substituted hydroxyaryl, optionally substituted carboxyalkyl, optionally substituted carboxyaryl, or optionally substituted aryl. Another non-limiting carboxylic acid is HO2C-R Ak -CO2H, R Ak is a bond, an optionally substituted alkylene, or an optionally substituted arylene (e.g., optionally substituted with halo, hydroxyl, carboxyl, alkoxy, and / or haloalkyl). In certain embodiments, the carboxylic acid is formic acid, citric acid, or salicylic acid.

[0112] In yet other embodiments, the metal chelator is a hydroxamic acid (R A1 -C(O)NR A2 OH, etc.) and R A1 and R A2are independently H, optionally substituted alkyl, or optionally substituted aryl, or optionally R A1 and R A2 collectively form an optionally substituted heterocyclyl.

[0113] The metal chelator may be or include a hydroxyketone. In certain embodiments, the hydroxyketone is R A1 -C(O)-R A2 where R A1 and R A2 each is an optionally substituted alkylene, an optionally substituted alkenylene, an optionally substituted heteroalkylene, or an optionally substituted heteroalkenylene, and R A1 and R A2 at least one of R A1 and R A2 taken together form a cyclic group (e.g., an optionally substituted cycloalkyl or an optionally substituted heterocyclyl).

[0114] In other embodiments, the hydroxyketone has the structure of the following formula (I), (II), or (III): [ka] , [ka] , [ka] , or a salt thereof, where X 1 and X 2 Each of these is independent and -CR 1 = or -N=, Each R 1 and R 2are independently H, optionally substituted alkyl, optionally substituted hydroxyalkyl, optionally substituted carboxyalkyl, —C(O)NR N1 R N2 , or -C(O)OR O1 where R N1 , R N2 , and ,R O1 are independently H, optionally substituted alkyl, or optionally substituted alkyl, and optionally R N1 and R N2 collectively form an optionally substituted heterocyclyl, R 3 are independently H, optionally substituted alkyl, or optionally substituted aryl.

[0115] Non-limiting hydroxyketones include hydroxypyridinone, hydroxypyrimidone, or hydroxypyrone, and substituted versions thereof. Additional hydroxyketones include 1-hydroxypyridin-2-one (6-R 1 Substituted 1,2-HOPO, such as 1,2-HOPO), 3-hydroxypyridin-4-one (NR 3 Substituted 3,4-HOPO and NR 3 ,2-R 2 ,6-R 3 Substituted 3,4-HOPO, such as 3,4-HOPO), 3-hydroxypyridin-2-one (NR 3 Substituted 3,2-HOPO and 4-R 3 ,6-R 1 Substituted 3,2-HOPO, such as 3,2-HOPO), 1-hydroxypyrazin-2-one (6-R 1 Substituted 1,2,4-HPM, such as 1,2,4-HPM), 1-hydroxypyridimin-2-one (6-R 1 1,2,3-HPM, such as substituted 1,2,3-HPM), and 3-hydroxypyran-4-one (2-R 1 Substituted 3,4-HPy, 5-R 2 Substitution and 2-R 1 ,5-R 2Substituted 3,4-HPy, such as 3,4-HPy, where the non-limiting substituents are depicted as formula (I), (II), or (III).

[0116] In some embodiments, the metal chelator comprises a plurality of moieties disposed on a backbone, wherein the plurality of moieties are selected from hydroxyl, carboxyl, amido, amino, and oxo. Non-limiting moieties include one or more of a dicarbonyl, diol, carboxylic acid, diacid, triacid, hydroxycarboxylic acid, hydroxamic acid, hydroxylactone, hydroxyketone, or salts thereof in mono- or polyvalent form.

[0117] The backbone can comprise any useful structure, such as optionally substituted alkyl, optionally substituted heteroalkyl, optionally substituted aryl, and combinations thereof. In other embodiments, the backbone comprises a polymer, e.g., a poly(ester) such as polyethylene terephthalate, polyhydroxybutyrate, polyhydroxyvalerate, poly(vinyl ester), poly(vinyl acetate), or copolymers thereof; poly(hydroxyalkanoate); poly(lactic acid); poly(caprolactone); polysaccharides such as amylose, cellulose, carboxymethyl cellulose, or derivatives thereof; poly(alkylene succinate) such as poly(propylene succinate) or poly(butylene succinate); poly(aspartate) or poly(aspartic acid); or an aliphatic-aromatic resin, such as a copolymer having at least one aliphatic moiety and at least one aromatic moiety.

[0118] Metal Precursors The present disclosure relates to the use of metal precursors and optional counter-reactants that can be deposited to form radiation-sensitive films (e.g., EUV-sensitive films). The films can then function as EUV resists, as further described herein. In certain embodiments, the films can include one or more ligands (e.g., labile ligands) that can be removed, cleaved, or crosslinked by radiation (e.g., EUV or DUV radiation).

[0119] The metal precursor can include any precursor (e.g., those described herein) that provides a radiation-sensitive, patternable film (or a patterned, radiation-sensitive, or photopatternable film). Such radiation can include EUV, DUV, or UV radiation, delivered by irradiating through a patterned mask to provide the patterning radiation. The film itself can be modified by exposure to such radiation to render the film radiation-sensitive. In certain embodiments, the metal precursor is an organometallic compound and includes at least one metal center.

[0120] The metal precursor may have any useful number and type of ligands. In some embodiments, the ligands may be characterized by their ability to react in the presence of a counter reactant or in the presence of patterning radiation. For example, the metal precursor may include a ligand (e.g., a dialkylamino group or an alkoxy group) that reacts with a counter reactant, thereby introducing a bond (e.g., an —O— bond) between the metal centers. In another example, the metal precursor may include a ligand that desorbs in the presence of patterning radiation. Such ligands (EUV-labile ligands) may include branched or linear alkyl groups with beta hydrogens and others described herein (e.g., R in Formula (IV) or (V)).

[0121] The metal precursor can be any useful metal-containing precursor, such as an organometallic agent, a metal halide, or a capping agent (e.g., those described herein). In a non-limiting example, the metal precursor comprises a structure having the following formula (IV): M a R b (IV), where: M is a metal or atom with a high EUV absorption cross section, each R is independently H, halo, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted alkoxy, optionally substituted alkanoyloxy, optionally substituted aryl, optionally substituted amino, optionally substituted bis(trialkylsilyl)amino, optionally substituted trialkylsilyl, oxo, anionic ligand, neutral ligand, or multidentate ligand; a≧1, b≧1.

[0122] In another non-limiting example, the metal precursor has a structure having the following formula (V): M a R b L c (V), where: M is a metal or atom with a high EUV absorption cross section, each R is independently halo, optionally substituted alkyl, optionally substituted aryl, optionally substituted amino, optionally substituted alkoxy, or L; each L is independently a ligand, anionic ligand, neutral ligand, multidentate ligand, ion, or other moiety that reacts with a counter reactant, where R and L and M collectively optionally form a heterocyclyl group, or R and L collectively may optionally form a heterocyclyl group; a≧1, b≧1, and c≧1.

[0123] In some embodiments, each ligand in the metal precursor can be a ligand that reacts with a counter reactant. In one example, the metal precursor has a structure having the formula (V), where each R is independently L. In another example, the metal precursor has a structure having the following formula (Va): M a L c (Va), where: M is a metal or atom with a high EUV absorption cross section, each L is independently a ligand, ion, or other moiety that reacts with a counter reactant, where two L may collectively optionally form a heterocyclyl group; a≧1 and c≧1. In certain embodiments of Formula (Va), a is 1. In further embodiments, c is 2, 3, or 4.

[0124] For any formula herein, M is a high patterning radiation absorption cross section (e.g., 1x10 7 cm 2M may be a metal, metalloid, or atom having an EUV absorption cross section of 1000 uV / mol or greater. In some embodiments, M is tin (Sn), tellurium (Te), bismuth (Bi), antimony (Sb), tantalum (Ta), cesium (Cs), indium (In), molybdenum (Mo), hafnium (Hf), iodine (I), zirconium (Zr), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), and platinum (Pt). In further embodiments, in Formula (IV), (V), or (Va), M is Sn, a is 1, and c is 4. In other embodiments, in Formula (IV), (V), or (Va), M is Sn, a is 1, and c is 2. In certain embodiments, M is Sn(II) (e.g., in formula (IV), (V), or (Va)), thereby providing a metal precursor that is a Sn(II)-based compound. In other embodiments, M is Sn(IV) (e.g., in formula (IV), (V), or (Va)), thereby providing a metal precursor that is a Sn(IV)-based compound. In certain embodiments, the precursor includes iodine (e.g., as in the case of periodate).

[0125] For any formula herein, each R is independently selected from H, halo, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted alkoxy (e.g., -OR 1 , where R 1 may be an optionally substituted alkyl group), an optionally substituted alkanoyloxy group, an optionally substituted aryl group, an optionally substituted amino group, an optionally substituted bis(trialkylsilyl)amino group, an optionally substituted trialkylsilyl group, an oxo group, an anionic ligand (e.g., oxide, chloride, hydride, acetate, iminodiacetate, etc.), a neutral ligand, or a multidentate ligand.

[0126] In some embodiments, the optionally substituted amino is —NR 1 R 2 where each R 1 and R 2 are independently H or alkyl groups, or R 1 and R 2 together with the nitrogen atom to which each is attached form a heterocyclyl group, as defined herein. In other embodiments, the optionally substituted bis(trialkylsilyl)amino group is —N(SiR 1 R 2 R 3 )2, where each R 1 , R 2 , and ,R 3 are independently an optionally substituted alkyl group. In yet other embodiments, the optionally substituted trialkylsilyl group is -SiR 1 R 2 R 3 where each R 1 , R 2 , and ,R 3 are independently optionally substituted alkyl groups.

[0127] In other embodiments, the formula is —NR 1 R 2 The first R (or first L) and the NR 1 R 2 and a second R (or second L) where each R 1 and R 2 are independently H or optionally substituted alkyl, or R from 1R (or 1L) 1 and R from the 2nd R (or 2nd L) 1 together with the nitrogen atom and metal atom to which each is attached, form a heterocyclyl group, as defined herein. 1 The first R is -OR 1 and a second R, each R 1are independently H or optionally substituted alkyl, or R 1 through R 1 and R from the 2nd R 1 together with the oxygen atom and metal atom to which each is attached, form a heterocyclyl group as defined herein.

[0128] In some embodiments, at least one of R or L (e.g., in formula (IV), (V), or (Va)) is an optionally substituted alkyl. Non-limiting alkyl groups include, for example, C n H 2n+1 (such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, or t-butyl), where n is 1, 2, 3, or greater than 4. In various embodiments, R or L has at least one beta hydrogen or beta fluorine.

[0129] In some embodiments, each R or L, or at least one R or L (e.g., in Formula (IV), (V), or (Va)) is halo. In particular, the metal precursor can be a metal halide. Non-limiting metal halides include SnBr4, SnCl4, SnI4, and SbCl3.

[0130] In some embodiments, each R or L, or at least one R or L (e.g., in Formula (IV), (V), or (Va)) may contain a nitrogen atom. In certain embodiments, one or more R or L is selected from the group consisting of optionally substituted amino, optionally substituted monoalkylamino (e.g., —NR 1 H, where R 1 is optionally substituted alkyl), optionally substituted dialkylamino (e.g., —NR 1 R 2 , where each R 1 and R 2are independently optionally substituted alkyl), or optionally substituted bis(trialkylsilyl)amino. Non-limiting R and L substituents can include, for example, -NMe, -NHMe, -NEt, -NHEt, -NMeEt, -N(t-Bu)-[CHCH]-N(t-Bu)-(tbba), N(SiMe), and N(SiEt).

[0131] In some embodiments, each R or L, or at least one R or L (e.g., in Formula (IV), (V), or (Va)) may include a silicon atom. In particular embodiments, one or more R or L may be an optionally substituted trialkylsilyl group or an optionally substituted bis(trialkylsilyl)amino. Non-limiting R or L substituents may include, for example, -SiMe3, -SiEt3, -N(SiMe3)2, and -N(SiEt3)2, etc.

[0132] In some embodiments, each R or L, or at least one R or L (e.g., in Formula (IV), (V), or (Va)) can include an oxygen atom. In certain embodiments, one or more R or L can be optionally substituted alkoxy or optionally substituted alkanoyloxy. Non-limiting R or L substituents include, for example, methoxy, ethoxy, isopropoxy (i-PrO), t-butoxy (t-BuO), acetate (OC(O)—CH), and —O═C(CH)—CH═C(CH)—O-(acac).

[0133] Any chemical formula herein may include one or more neutral ligands. Non-limiting neutral ligands include optionally substituted amine, optionally substituted ether, optionally substituted alkyl, optionally substituted alkene, optionally substituted alkyne, optionally substituted benzene, oxo, or carbon monoxide.

[0134] Any formula herein may include one or more polydentate (e.g., bidentate) ligands. Non-limiting polydentate ligands include diketonates (e.g., acetylacetonate (acac) or -OC(R 1 )-Ak-(R 1 )CO- or -OC(R 1 )-C(R 2 )-(R 1 )CO-), bidentate chelate dinitrogen (e.g., -N(R 1 )-Ak-N(R 1 )- or -N(R 3 )-CR 4 -CR 2 =N(R 1 )-), aromatic (e.g., -Ar-), amidinate (e.g., -N(R 1 )-C(R 2 )-N(R 1 )-), aminoalkoxides (e.g., -N(R 1 )-Ak-O- or -N(R 1 )2-Ak-O-), diazadienyl (e.g., -N(R 1 )-C(R 2 )-C(R 2 )-N(R 1 )-), cyclopentadienyl, pyrazolate, optionally substituted heterocyclyl, optionally substituted alkylene, or optionally substituted heteroalkylene. In certain embodiments, each R 1 are independently H, optionally substituted alkyl, optionally substituted haloalkyl, or optionally substituted aryl, and each R 2 are independently H or optionally substituted alkyl, and R 3 and R 4 collectively form an optionally substituted heterocyclyl, Ak is optionally substituted alkylene, and Ar is optionally substituted arylene.

[0135] In certain embodiments, the metal precursor comprises tin. In some embodiments, the tin precursor comprises SnR or SnR2 or SnR4 or R3SnSnR3, where each R is independently H, halo, optionally substituted C 1-12 Alkyl, optionally substituted C 1-12 alkoxy, optionally substituted amino (e.g., —NR 1 R 2 ), optionally substituted C 2-12 Alkenyl, optionally substituted C 2-12 Alkynyl, optionally substituted C 3-8 Cycloalkyl, optionally substituted aryl, cyclopentadienyl, optionally substituted bis(trialkylsilyl)amino (e.g., —N(SiR 1 R 2 R 3 )2), optionally substituted alkanoyloxy (e.g., acetate), diketonate (e.g., —OC(R 1 )-Ak-(R 2 )CO-), or bidentate chelate dinitrogen (e.g., -N(R 1 )-Ak-N(R 1 In certain embodiments, each R 1 , R 2 , and ,R 3 are independent and can be H or C 1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl), and Ak is optionally substituted C 1-6Non-limiting examples of tin precursors include SnF, SnH, SnBr, SnCl, SnI, tetramethyltin (SnMe), tetraethyltin (SnEt), trimethyltin chloride (SnMeCl), dimethyltin dichloride (SnMeCl), methyltin trichloride (SnMeCl), tetraallyltin, tetravinyltin, hexaphenylditin(IV) (PhSn-SnPh, where Ph is phenyl), di(Sn-SnPh ... Butyldiphenyltin (SnBu2Ph2), trimethyl(phenyl)tin (SnMe3Ph), trimethyl(phenylethynyl)tin, tricyclohexyltin hydride, tributyltin hydride (SnBu3H), dibutyltin diacetate (SnBu2(CH3COO)2), tin(II) acetylacetonate (Sn(acacac)2), SnBu3(OEt), SnBu2(OMe)2, SnBu3(OMe), Sn( t-BuO)4, Sn(n-Bu)(t-BuO)3, tetrakis(dimethylamino)tin (Sn(NMe2)4), tetrakis(ethylmethylamino)tin (Sn(NMeEt)4), tetrakis(diethylamino)tin(IV) (Sn(NEt2)4), (dimethylamino)trimethyltin(IV) (Sn(Me)3(NMe2), Sn(i-Pr)(NMe2)3, Sn(n-Bu)(NMe2)3, Sn(s-Bu)(NM e2)3, Sn(i-Bu)(NMe2)3, Sn(t-Bu)(NMe2)3, Sn(t-Bu)2(NMe2)2, Sn(t-Bu)(NEt2)3, Sn(tbba), Sn(II) (1,3-bis(1,1-dimethylethyl)-4,5-dimethyl-(4R,5R)-1,3,2-diazastannolidin-2-ylidene), or bis[bis(trimethylsilyl)amino]tin (Sn[N(SiMe3)2]2).

[0136] In other embodiments, the metal precursor comprises bismuth (such as in BiR), where each R is independently halo, optionally substituted C 1-12 Alkyl, mono-C 1-12 Alkylamino (e.g., -NR 1 H), Di-C 1-12 Alkylamino (e.g., -NR 1R 2 ), optionally substituted aryl, optionally substituted bis(trialkylsilyl)amino (e.g., —N(SiR 1 R 2 R 3 )2), or diketonates (e.g., -OC(R 4 )-Ak-(R 5 )CO-). In certain embodiments, each R 1 , R 2 , and ,R 3 is independent and C 1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl), and each R 4 and R 5 are independently H or optionally substituted C 1-12 and alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl). Non-limiting bismuth precursors include BiCl3, BiMe3, BiPh3, Bi(NMe2)3, Bi[N(SiMe3)2]3, and Bi(thd)3, where thd is 2,2,6,6-tetramethyl-3,5-heptanedionate.

[0137] In other embodiments, the metal precursor comprises tellurium (such as TeR2 or TeR4), where each R is independently halo, C 1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl), optionally substituted C 1-12 alkoxy, optionally substituted aryl, hydroxyl, oxo, or optionally substituted trialkylsilyl. Non-limiting tellurium precursors include dimethyltellurium (TeMe), diethyltellurium (TeEt), di(n-butyl)tellurium (Te(n-Bu)), di(isopropyl)tellurium (Te(i-Pr)), di(t-butyl)tellurium (Te(t-Bu)), t-butyltellurium hydride (Te(t-Bu)(H)), Te(OEt), bis(trimethylsilyl)tellurium (Te(SiMe)), and bis(triethylsilyl)tellurium (Te(SiEt)).

[0138] The metal precursor may include cesium. Non-limiting cesium precursors include Cs(OR), where R is optionally substituted C 1-12 It is alkyl or optionally substituted aryl. Other cesium precursors include Cs(Ot-Bu) and Cs(Oi-Pr).

[0139] The metal precursor may include antimony (such as in SbR3), where each R is independently halo, optionally substituted C 1-12 Alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, and neopentyl), optionally substituted C 1-12 Alkoxy or optionally substituted amino (e.g., —NR 1 R 2 , where each R 1 and R 2 are independently H or optionally substituted C 1-12 Non-limiting antimony precursors include SbCl3, Sb(OEt)3, Sb(On-Bu)3, and Sb(NMe2)3.

[0140] Other metal precursors include indium precursors (such as in InR3), where each R is independently halo, optionally substituted C 1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, and neopentyl) or diketonate (e.g., -OC(R 4 )-Ak-(R 5 )CO-, where each R 4 and R 5 are independent and can be H or C 1-12 Non-limiting indium precursors include InCp, where Cp is cyclopentadinyl, InCl, InMe, In(acac), In(CFCOCHCOCH), and In(thd).

[0141] Still other metal precursors include molybdenum precursors (MoR4, MoR5, MoR6, etc.), where each R is independently an optionally substituted C 1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, and neopentyl), optionally substituted aryl (e.g., allyl such as C3H5 or an oxide of allyl such as C5H5O), optionally substituted alkylimido (e.g., =NR 1 ), acetonitrile, optionally substituted amino (e.g., —NR 1 R 2 ), halo (e.g., chloro or bromo), carbonyl, diketonate (e.g., OC(R 3 )-Ak-(R 3 )CO-), or bidentate chelate dinitrogen (e.g., N(R 3 )-Ak-N(R 3 )- or -N(R 4 )-CR 5 -CR 2 =N(R 3 In certain embodiments, each R 1 and each R 2 are independently H or optionally substituted alkyl, and each R 3 are independently H, optionally substituted alkyl, optionally substituted haloalkyl, or optionally substituted aryl; R 4 and R 5 collectively form an optionally substituted heterocyclyl. Non-limiting molybdenum precursors include Mo(CO), bis(t-butylimido)bis(dimethylamino)molybdenum(VI) or Mo(NMe)(=NT-Bu), molybdenum dioxide(VI) bis(2,2,6,6-tetramethyl-3,5-heptanedionate) or Mo(=O)(thd), or molybdenum allyl complexes (Mo(η 3 -allyl)X(CO)2(CH3CN)2, etc.), where allyl can be C3H5 or C5H5O, and X can be Cl, Br, or alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl).

[0142] Metal precursors may include hafnium precursors (such as HfR3 and HfR4), where each R is independently an optionally substituted C 1-12 Alkyl, optionally substituted C 1-12 Alkoxy, Mono-C 1-12 Alkylamino (e.g., NR 1 H, where R 1 is an optionally substituted C 1-12 alkyl), di-C 1-12 Alkylamino (e.g., NR 1 R 2 , each R 1 and R 2 are independent and optionally substituted C 1-12 alkyl), optionally substituted aryl (e.g., phenyl, benzene, or cyclopentadienyl, and substituted forms thereof), optionally substituted aryl (e.g., allyl or allyl oxide), or diketonate (e.g., OC(R 4 )-Ak-(R 5 )CO-, each R 4 and R 5 are independently H or optionally substituted C 1-12 Non-limiting hafnium precursors are HF(I-Pr)(NMe2)3, HF(η-CH5R 1 )(η-C3H5)2(R 1 is H or alkyl), HfR 1 (NR 2 R 3 )3(where R 1 , R 2 , and ,R 3 each independently represents an optionally substituted C 1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl), HfCp2Me2, Hf(Ot-Bu)4, Hf(OEt)4; Hf(NEt2)4, Hf(NMe2)4; Hf(NMeEt)4, and Hf(thd)4.

[0143] Further metal precursors and non-limiting substituents are described herein. For example, the metal precursor may be any precursor having the structure of formula (IV), (V), and (Va), as described above, or any precursor having the structure of formula (VI), (VII), (VIII), (IX), (X), or (XI), as described below. Any of the substituents M, R, X, or L described herein may be used in any of formulas (IV), (V), (Va), (VI), (VII), (VIII), (IX), (X), or (XI).

[0144] Various atoms present in the metal precursor and / or counter reactant can be provided within the gradient film. In some embodiments of the techniques discussed herein, a non-limiting strategy that can further improve EUV sensitivity in photoresist (PR) films is to create a film with a vertically graded film composition, resulting in depth-dependent EUV sensitivity. In homogeneous PR with a high absorption coefficient, the light intensity decreases throughout the film's depth, requiring a higher EUV dose to ensure the bottom is fully exposed. Increasing the density of atoms with higher EUV absorption at the bottom of the film compared to the top (i.e., creating a gradient with increasing EUV absorption) allows for more efficient use of available EUV photons while more uniformly distributing absorption (and secondary electron effects) toward the more absorbing bottom of the film. In one non-limiting example, the gradient film includes Te, I, or other atoms toward the bottom of the film (e.g., toward the substrate).

[0145] The strategy of engineering vertical compositional gradients within PR films is particularly applicable to dry deposition processes (such as MLD, CVD, and ALD) and can be achieved by adjusting the flow ratios between different reactants during deposition. Types of compositional gradients that can be engineered include ratios between different highly absorbing metals, the proportion of metal atoms with EUV-cleavable organic groups, the proportion of reactants containing highly absorbing elements, and combinations of the above.

[0146] Additionally, compositional gradients in EUV PR films can provide additional benefits. For example, a high density of highly EUV-absorbing elements in the lower part of the film can effectively generate more secondary electrons that can better expose the upper part of the film. Furthermore, such compositional gradients can be directly correlated with a higher proportion of EUV-absorbing species that are not attached to bulky terminal substituents. For example, in the case of Sn-based resists, it is possible to incorporate tin precursors with four leaving groups, which can promote the formation of Sn-O-substrate bonds at the interface for improved adhesion.

[0147] Such gradient films can be formed using any of the metal precursors (eg, tin precursors or non-tin precursors) and / or counter reactants described herein. Still other films, methods, precursors, and other compounds are described in U.S. Provisional Patent Application No. 62 / 909,430, filed October 2, 2019, and International Application No. PCT / US20 / 53856, filed October 1, 2020, published as International Publication No. WO2021 / 067632, entitled "SUBSTRATE SURFACE MODIFICATION WITH HIGH EUV ABSORBERS FOR HIGH PERFORMANCE EUV PHOTORESISTS," and International Application No. PCT / US20 / 70172, filed June 24, 2020, published as International Publication No. WO2020 / 264557, entitled "PHOTORESIST WITH MULTIPLE PATTERNING RADIATION-ABSORBING ELEMENTS AND / OR VERTICAL COMPOSITIONS." and "Direct Photopatternable Metal Oxide Films for Forming EUV Resist Masks," in US Pat. No. 6,499,499, the disclosure of which is hereby incorporated by reference, at least for its disclosure regarding the composition, deposition, and patterning of directly photopatternable metal oxide films to form EUV resist masks.

[0148] Furthermore, two or more different precursors may be utilized within each layer (e.g., film). For example, two or more of any metal-containing precursors herein may be utilized to form an alloy. In one non-limiting example, tin telluride may be formed using a tin precursor containing an -NR2 ligand with an RTeH, RTed, or TeR2 precursor, where R is alkyl (e.g., t-butyl or i-propyl). In another example, a metal telluride may be formed using a first metal precursor containing an alkoxy or halo ligand (e.g., SbCl3) with a tellurium-containing precursor containing a trialkylsilyl ligand (e.g., bis(trimethylsilyl)tellurium).

[0149] Still other exemplary EUV-sensitive materials and processing methods and apparatus are described in U.S. Pat. No. 9,996,004 and International Patent Publication No. WO2019 / 217749, each of which is incorporated herein by reference in its entirety.

[0150] As described herein, the films, layers, and methods herein can be used with any useful precursor. In some examples, the metal precursor comprises a metal halide having the following chemical formula (VI): MX n (VI), where M is a metal, X is halo, and n is 2-4 depending on the selection of M. Examples of metals for M include Sn, Te, Bi, or Sb. Examples of metal halides include SnBr4, SnCl4, SnI4, and SbCl3.

[0151] Another non-limiting metal precursor has a structure having formula (VII): MR n (VII), where M is a metal and each R is independently H, optionally substituted alkyl, amino (e.g., -NR2, where each R is independently alkyl), optionally substituted bis(trialkylsilyl)amino (e.g., -N(SiR3)2, where each R is independently alkyl), or optionally substituted trialkylsilyl (e.g., -SiR3, where each R is independently alkyl), and n is 2 to 4, depending on the selection of M. Examples of metals for M include Sn, Te, Bi, or Sb. The alkyl group can be C n H 2n+1 where n is 1, 2, 3, or greater than 4. Examples of organometallic agents include SnMe4, SnEt4, TeRn, RTaR, t-butyl tellurium hydride (Te(t-Bu)(H)), dimethyl tellurium (TeMe2), di(t-butyl) tellurium (Te(t-Bu)2)), di(isopropyl) tellurium (Te(i-Pr)2), bis(trimethylsilyl) tellurium (Te(SiMe3)2), bis(triethylsilyl) tellurium (Te(SiEt3)2), tris(bis(trimethylsilyl)amido)bismuth (Bi[N(SiMe3)2]3), Sb(NMe2)3, and the like.

[0152] Another non-limiting metal-containing precursor can include a capping agent having the following formula (VIII): ML n (VIII), where M is a metal and each L is independently an optionally substituted alkyl, amino (e.g., —NR 1 R 2 , where R 1 and R 2Each of may be H or alkyl (such as any described herein), alkoxy (e.g., -OR, where R is alkyl (such as any described herein)), halo, or other organic substituent, and n is 2-4 depending on the selection of M. Examples of metals for M include Sn, Te, Bi, or Sb. Example ligands are dialkylamino (e.g., dimethylamino, methylethylamino, and diethylamino), alkoxy (e.g., t-butoxy and isopropoxy), halo (e.g., F, Cl, Br, and I), or other organic substituent (e.g., acetylacetone or N 2 ,N 3 -di-tert-butyl-butane-2,3-diamino). Non-limiting capping agents include SnCl, SnI, Sn(NR), where each R is independently methyl or ethyl, or Sn(t-BuO). In some embodiments, multiple types of ligands are present.

[0153] The metal-containing precursor may include a hydrocarbyl-substituted capping agent having the following formula (IX): R n MX m (IX), where M is a metal and R is C 2-10where X is an alkyl or substituted alkyl having a beta hydrogen, and X is a leaving group suitable for reaction with the hydroxyl group of the exposed hydroxyl group. In various embodiments, n=1-3 and m=4-n, 3-n, or 2-n, where m>0 (i.e., m≧1). For example, R can be t-butyl, t-pentyl, t-hexyl, cyclohexyl, isopropyl, isobutyl, sec-butyl, n-butyl, n-pentyl, n-hexyl, or a derivative thereof having a heteroatom substituent at the beta position. Suitable heteroatoms include halogen (F, Cl, Br, or I) or oxygen (—OH or OR). X can be dialkylamino (e.g., dimethylamino, methylethylamino, or diethylamino), alkoxy (e.g., t-butoxy, isopropoxy), halo (e.g., F, Cl, Br, or I), or another organic ligand. Examples of hydrocarbyl-substituted capping agents include t-butyltris(dimethylamino)tin (Sn(t-Bu)(NMe2)3), n-butyltris(dimethylamino)tin (Sn(n-Bu)(NMe2)3), t-butyltris(diethylamino)tin (Sn(t-Bu)(NEt2)3), di(t-butyl)di(dimethylamino)tin (Sn(t-Bu)2(NMe2)2), sec-butyltris(dimethylamino)tin (Sn(s-Bu)(NMe2)3), n-pentyltris(dimethylamino)tin (Sn(s-Bu)(NMe2)3), tris(dimethylamino)tin (Sn(n-pentyl)(NMe2)3), i-butyltris(dimethylamino)tin (Sn(i-Bu)(NMe2)3), i-propyltris(dimethylamino)tin (Sn(i-Pr)(NMe2)3), t-butyltris(t-butoxy)tin (Sn(t-Bu)(t-BuO)3), n-butyl(tris(t-butoxy)tin (Sn(n-Bu)(t-BuO)3), or isopropyltris(t-butoxy)tin (Sn(i-Pr)(t-BuO)3).

[0154] In various embodiments, the metal-containing precursor comprises at least one alkyl group on each metal atom that can remain after the gas-phase reaction, while other ligands or ions coordinated to the metal atom can be replaced by counter reactants. Thus, another non-limiting metal-containing precursor comprises an organometallic agent having the formula (X): M a R b L c (X), where M is a metal, R is an optionally substituted alkyl, L is a ligand, ion, or other moiety that reacts with a counter reactant, and a≧1, b≧1, and c≧1. In certain embodiments, a=1, and b+c=4. In some embodiments, M is Sn, Te, Bi, or Sb. In certain embodiments, each L is independently an amino (e.g., —NR 1 R 2 , where R 1 and R 2 Each of R may be H or alkyl (such as any described herein), alkoxyl (e.g., —OR, where R may be alkyl (such as any described herein), or halo (e.g., F, Cl, Br, or I). Examples of organometallic agents include SnMe3Cl, SnMe2Cl2, SnMeCl3, SnMe(NMe2), SnMe2(NMe2), SnMe3(NMe2), and the like.

[0155] In other embodiments, non-limiting metal-containing precursors include organometallic agents having formula (XI): M a L c (XI), where M is a metal and L is a ligand, ion, or other moiety that reacts with a counter reactant, where a≧1 and c≧1. In certain embodiments, c=n−1, where n is 2, 3, or 4. In some embodiments, M is Sn, Te, Bi, or Sb. Preferably, the counter reactant can be substituted with a reactive moiety, ligand, or ion (e.g., L in the formulas herein) to join at least two metal atoms in a chemical bond.

[0156] In any embodiment herein, R is optionally substituted alkyl (e.g., C 1-10 In one embodiment, the alkyl can be substituted with one or more halo (e.g., halo-substituted C 1 , including 1, 2, 3, 4, or 5 or more halo (e.g., F, Cl, Br, or I). 1-10 alkyl). Examples of R substituents are C n H 2n+1 (where n≧3 is preferred), and C n F x H (2n+1-x) where 2n+1≦x≦1. In various embodiments, R has at least one beta hydrogen or beta fluorine. For example, R may be selected from the group consisting of i-propyl, n-propyl, t-butyl, i-butyl, n-butyl, sec-butyl, n-pentyl, i-pentyl, t-pentyl, sec-pentyl, and mixtures thereof.

[0157] In any embodiment herein, L is an amino (e.g., —NR 1 R 2 , R 1 and R 2may be any moiety that is readily displaced by a counter reactant to generate the moiety M-OH, such as a moiety selected from the group consisting of H or alkyl (such as any described herein), alkoxy (e.g., —OR, where R may be alkyl (such as any described herein)), carboxylate, halo (e.g., F, Cl, Br, or I), and mixtures thereof.

[0158] Examples of organometallic agents are SnMeCl3, (N 2 ,N 3 -di-t-butyl-butane-2,3-diamido)tin(II) (Sn(tbba)), bis(bis(trimethylsilyl)amido)tin(II), tetrakis(dimethylamino)tin(IV) (Sn(NMe2)4), t-butyltris(dimethylamino)tin (Sn(t-butyl)(NMe2)3), i-butyltris(dimethylamino)tin (Sn(i-Bu)(NMe2)3), n-butyltris(dimethylamino)tin (Sn(n-Bu) )(NMe2)3), sec-butyltris(dimethylamino)tin (Sn(s-Bu)(NMe2)3), i-propyl(tris)dimethylaminotin (Sn(i-Pr)(NMe2)3), n-propyltris(diethylamino)tin (Sn(n-Pr)(NEt2)3), and analogous alkyl(tris)(t-butoxy)tin compounds, such as t-butyltris(t-butoxy)tin (Sn(t-Bu)(t-BuO)3). In some embodiments, the organometallic agent is partially fluorinated.

[0159] Lithography Processing EUV lithography utilizes an EUV resist, which may be a polymer-based chemically amplified resist produced by a liquid-based spin-on technique, a metal oxide-based resist produced by a spin-on technique, or a metal oxide-based resist produced by a dry deposition technique. Such an EUV resist may include any EUV-sensitive film or material described herein. The lithography method may include, for example, patterning the resist by exposing the EUV resist to EUV radiation to form a photopattern, and then developing the pattern by removing portions of the resist according to the photopattern to form a mask.

[0160] It should also be understood that while the present disclosure relates to lithographic patterning techniques and materials, using EUV lithography as an example, it is also applicable to other next-generation lithography technologies. In addition to EUV, including the standard 13.5 nm EUV wavelength currently being used and developed, the most suitable radiation sources for such lithography are DUV (deep UV) (generally referring to the use of 248 nm or 193 nm excimer laser sources), X-ray (which formally includes EUV in the relatively low energy range of the X-ray range), and e-beam (which can cover a wide energy range). Such methods include contacting a substrate (e.g., optionally having exposed hydroxyl groups) with a metal-containing precursor (e.g., any precursor described herein) to form a film of metal oxide (e.g., a layer including a network of metal oxide bonds, which may also include other non-metallic and non-oxygen groups) as an imaging / PR layer on the substrate surface. Specific methods may depend on the particular materials and applications used for the semiconductor substrate and final semiconductor device. Thus, the methods described herein are merely illustrative of methods and materials available in the state of the art.

[0161] Directly photopatternable EUV resists may be composed of or include metals and / or metal oxides mixed within an organic component. Metals / metal oxides are highly promising in that they may enhance EUV photon absorption, generate secondary electrons, and / or exhibit high etch selectivity relative to underlying film stacks and device layers. Additionally, wet (solvent) approaches are included in this disclosure. In wet development, the wafer may be exposed to a developing solvent, dried, and baked.

[0162] Deposition processes such as dry or wet deposition As described above, the present disclosure provides methods for forming an imaging layer on a semiconductor substrate that can be patterned using EUV or other next-generation lithography techniques. The methods include methods in which a polymerized organometallic material is produced in a vapor or solvent and deposited on the substrate. In some embodiments, the deposition can utilize any useful metal-containing precursor (e.g., a metal halide, capping agent, or organometallic agent described herein) as a dry or spin-on formulation. The deposition process can include applying an EUV-sensitive material as a resist film. Examples of EUV-sensitive materials are described herein.

[0163] The present technology includes methods for depositing EUV-sensitive films onto substrates, such films being capable of acting as resists for subsequent EUV lithography and processing.

[0164] Such EUV-sensitive films include materials that, upon exposure to EUV, undergo changes such as the loss of bulky pendant ligands bonded to metal atoms within a low-density M-OH-rich material, allowing crosslinking to a denser M-OM-bonded metal oxide material. In other embodiments, EUV exposure results in additional crosslinking between ligands bonded to metal atoms, thereby providing a denser M-OM-bonded organometallic material, where L is a ligand. In yet other embodiments, EUV exposure results in the loss of ligands to provide a M-OH material that can be removed by a positive-tone developer.

[0165] EUV patterning results in the formation of regions of the film with altered physical or chemical properties compared to unexposed regions. These properties can be exploited in subsequent processing, such as to dissolve either the unexposed or exposed regions, or to selectively deposit material in either the exposed or unexposed regions. In some embodiments, the unexposed film has a hydrophobic surface, and the exposed film has a hydrophilic surface under the conditions under which such subsequent processing is carried out (it being understood that the hydrophilicity of the exposed and unexposed regions is relative to one another). For example, material removal may be achieved by exploiting differences in the film's chemical composition, density, and cross-linking. Removal may be by wet processing, as further described herein.

[0166] The thickness of the EUV-patternable film formed on the surface of a substrate can vary depending on the surface characteristics, the material being utilized, and the processing conditions. In various embodiments, the film thickness can range from about 0.5 nm to about 100 nm. The film preferably has a thickness sufficient to absorb most of the EUV light under EUV patterning conditions. For example, the total absorption of the resist film can be 30% or less (e.g., 10% or less or 5% or less) so that the resist material at the bottom of the resist film is fully exposed. In some embodiments, the film thickness is 10 nm to 20 nm. Furthermore, as discussed above, the deposited film can closely conform to surface features, providing advantages in forming a mask on a substrate (such as a substrate with underlying features) without "filling" or otherwise planarizing such features.

[0167] The film (e.g., imaging layer) may be comprised of a metal oxide layer deposited by any useful method. Such a metal oxide layer may be deposited or applied using any EUV-sensitive material described herein, such as a metal-containing precursor (e.g., a metal halide, capping agent, or organometallic agent). In an exemplary process, a polymerized organometallic material is formed in the vapor phase, in the liquid phase, or in situ on the surface of a substrate to provide a metal oxide layer. The metal oxide layer may be used as a film, an adhesion layer, or a capping layer.

[0168] Optionally, the metal oxide layer may include a hydroxyl-terminated metal oxide layer, which may be deposited by utilizing a capping agent (e.g., any of those described herein) with an oxygen-containing reactant. Such a hydroxyl-terminated metal oxide layer may be utilized as an adhesion layer between two other layers, such as, for example, between a substrate and a film and / or between a photoresist layer and an underlayer.

[0169] Examples of deposition techniques (e.g., for films) include any of the techniques described herein, such as ALD (e.g., thermal ALD and plasma-enhanced ALD), spin-coat deposition, PVD such as PVD co-sputtering, CVD (e.g., PE-CVD or LP-CVD), sputter deposition, e-beam evaporation including e-beam co-evaporation, or combinations thereof (e.g., combining ALD and CVD components, discontinuous ALD-like processes in which the metal-containing precursor and counter reactant are separated in time or space, etc.).

[0170] Further description of precursors applicable to the present disclosure and methods for depositing them as EUV photoresist films can be found in International Application No. PCT / US19 / 31618, "METHODS FOR MAKING EUV PATTERNABLE HARD MASKS," filed May 9, 2019, and published as International Publication No. WO2019 / 217749. The thin films may include optional materials in addition to the metal precursor and counter reactant to alter the chemical or physical properties of the film, such as to modify the film's sensitivity to EUV or to increase etch resistance. Such optional materials may be introduced, such as by doping, before deposition on the substrate, after deposition of the film, or both. In some embodiments, a mild remote H plasma may be introduced, for example, to replace some Sn-L bonds with Sn-H, thereby enhancing the reactivity of the resist under EUV.

[0171] Dry deposition processes may include mixing a vapor flow of a metal precursor (e.g., a metal-containing precursor such as an organometallic agent) with a vapor flow of an optional counter reactant to form a polymerized organometallic material, and depositing the organometallic material on the surface of a semiconductor substrate. In some embodiments, the polymerized organometallic material can be formed by mixing the metal-containing precursor with the optional counter reactant. As will be appreciated by those skilled in the art, the mixing and deposition aspects of the process may be performed in parallel in a substantially continuous process. Wet deposition processes may include providing such precursor or polymerized organometallic material in a liquid solvent.

[0172] In an example of a sequential CVD process, two or more gas streams of a source of a metal precursor and an optional counter reactant are introduced into a deposition chamber of a CVD apparatus via separate inlets, where the gases mix and react in the vapor phase to form a coagulated polymer material or film on a substrate (e.g., by forming metal-oxygen-metal bonds). The gas streams may be introduced using, for example, separate inlets or a dual plenum showerhead. The apparatus is configured to allow the flows of the metal precursor and the optional counter reactant to mix within the chamber, allowing the metal precursor and the optional counter reactant to react to form a polymerized organometallic material or film (e.g., a metal oxide coating or a coagulated polymer material, such as by forming metal-oxygen-metal bonds).

[0173] To deposit metal oxides, CVD processes are typically performed at reduced pressures, such as between 0.1 Torr and 10 Torr. In some embodiments, the process is performed at a pressure between 1 Torr and 2 Torr. The temperature of the substrate is preferably lower than the temperature of the reactant stream. For example, the substrate temperature can be between 0°C and 250°C, or between ambient temperature (e.g., 23°C) and 150°C.

[0174] To deposit coagulated polymeric materials, CVD processes are typically performed at reduced pressures, such as 10 mTorr to 10 Torr. In some embodiments, processes are performed at 0.5 to 2 Torr. The temperature of the substrate is preferably equal to or less than the temperature of the reactant stream. For example, the substrate temperature can be between 0°C and 250°C, or between ambient temperature (e.g., 23°C) and 150°C. In various processes, deposition of polymerized organometallic materials onto a substrate occurs at a rate that is inversely proportional to the surface temperature. Without limiting the mechanism, function, or utility of the present technology, it is believed that the products of such gas-phase reactions have a high molecular weight as metal atoms are crosslinked with counter reactants before condensing or otherwise depositing on the substrate.

[0175] Deposition methods can be used to tailor the composition of the film as it grows. In CVD processes, this can be achieved by varying the relative flow rates of the metal precursor and counter reactant during deposition. Deposition can occur at temperatures between 30°C and 200°C and pressures between 0.01 Torr and 100 Torr (more commonly, about 0.1 Torr and 10 Torr).

[0176] Films (e.g., metal oxide coatings or aggregated polymer materials, such as by forming metal-oxygen-metal bonds) may also be deposited by ALD processes. For example, a metal precursor and an optional counter reactant are introduced at separate times representing ALD cycles. The metal precursor reacts on the surface to form up to a monolayer of material at a time during each cycle. This allows for excellent control of film thickness uniformity across the surface. ALD processes are typically performed at reduced pressures, such as 0.1 Torr to 10 Torr. In some embodiments, the process is performed at 1 Torr to 2 Torr. The substrate temperature may be between 0°C and 250°C, or between ambient temperature (e.g., 23°C) and 150°C. The process may be a thermal process or, preferably, a plasma-assisted deposition.

[0177] Any of the vapor deposition methods herein can be modified to allow for the use of two or more different metal precursors. In one embodiment, the precursors can contain the same metal but different ligands. In another embodiment, the precursors can contain different metal groups. In one non-limiting example, alternating flows of various volatile metal-containing precursors can provide a mixed metal layer, such as using a metal alkoxide precursor having a first metal (e.g., Sn) with a silyl-based precursor having a different second metal (e.g., Te). Additionally, any of the vapor deposition methods herein can be modified to allow for the use of two or more different counter reactants.

[0178] Additionally, any of the deposition methods herein can be modified to provide one or more layers within a film. In one example, different metal precursors may be used in each layer. In another example, the same precursor may be used for each layer, but the top layer can have a different chemical composition (e.g., a different density of metal-ligand bonding, a different metal-to-carbon ratio, or different bonding ligands provided by adjusting or varying the metal precursor).

[0179] The processes described herein can be used to achieve surface modification. Vapors of a metal precursor may be passed over the wafer in several iterations. The wafer may be heated to provide thermal energy for the reaction to proceed. During several iterations, heating may be between about 50°C and about 250°C. In some cases, pulses of counter reactants may be utilized, separated by pumping and / or purging steps. For example, counter reactants may be pulsed between precursor pulses to induce ALD or ALD-like growth. In other cases, both precursor and counter reactant may be flowed simultaneously. Examples of elements useful for surface modification include I, F, Sn, Bi, Sb, Te, and oxides or alloys of these compounds.

[0180] The processes herein can be used to deposit thin metal oxides or metals. Examples include SnOx, BiOx, and Te. After deposition, the films can be further processed using M as described elsewhere herein. a R b L c The surface may be capped with an alkyl-substituted precursor in the form of . A counter reactant may be used to better remove the ligands, and multiple cycles may be repeated to ensure complete saturation of the substrate surface. The surface is then ready for deposition of an EUV-sensitive film. One possible method is to produce a thin film of SnOx. Possible chemical reactions include the growth of SnO2 by cycling tetrakis(dimethylamino)tin and a counter reactant (such as water or O2 plasma). After growth, a capping agent may be applied. For example, isopropyltris(dimethylamino)tin vapor may be flowed over the surface.

[0181] The deposition process can be used on any useful surface. As referred to herein, a "surface" is a surface onto which the film of the present technology is deposited or exposed to EUV during the process. Such a surface can be on a substrate (e.g., onto which a film is deposited), on a film (e.g., onto which a capping layer can be deposited), or on an underlayer.

[0182] Any useful substrate may be used, including any material composition suitable for lithographic processing, particularly for the fabrication of integrated circuits and other semiconductor devices. In some embodiments, the substrate is a silicon wafer. The substrate may be a silicon wafer with features formed thereon ("underlying topographic features"), having an irregular surface topography.

[0183] Such underlying topographical features may include areas where material has been removed (e.g., by etching) or where material has been added (e.g., by deposition) during processing prior to performing the methods of the present technique. Such pre-processing may involve the methods of the present technique or other processing methods in an iterative process in which two or more layers of features are formed on a substrate. Various advantages may be gained from the conformance of the present technique's films to underlying features without "filling" or otherwise planarizing such features, and the ability to deposit films on a variety of material surfaces.

[0184] In some embodiments, an input wafer may be prepared having a substrate surface of a desired material, with the top material being the layer to which the resist pattern will be transferred. The choice of material may vary depending on the integration, but it is generally desirable to select a material that can be etched with high selectivity (i.e., much faster) relative to the EUV resist or imaging layer. Suitable substrate materials include various carbon-based films (e.g., ashable hard masks (AHMs)), silicon-based films (e.g., SiO x , SiO x N y , SiO x C y Nz The layer may comprise a silicon, silicon oxide, silicon nitride, silicon oxynitride, or silicon oxycarbonitride, such as a-Si:H, poly-Si, or SiN, as well as doped forms thereof, or any other film (typically a sacrificial film) applied to facilitate the patterning process.

[0185] In some embodiments, the substrate is a hard mask, which is used in lithographic etching of the underlying semiconductor material. The hard mask may be made of amorphous carbon (aC), SnO x , SiO2, SiO x N y , SiO x C, Si3N4, TiO2, TiN, W, W-doped C, WO x For example, the substrate may preferably be SnO. x (such as SnO2). In various embodiments, the layer may be 1 nm to 100 nm thick, or 2 nm to 10 nm thick.

[0186] In some non-limiting embodiments, the substrate comprises an underlayer. The underlayer may be deposited over a hard mask or other layer, as described herein, and generally underlies the imaging layer (or film). The underlayer may be used to improve the sensitivity of the PR, enhance EUV absorption, and / or improve the patterning performance of the PR. If device features that create significant topography are present on the substrate to be patterned, another important function of the underlayer may be to overlay and planarize the existing topography so that subsequent patterning steps can be performed on all areas of the pattern in focus and on a flat surface. For such applications, the underlayer (or at least one of the underlayers) may be applied using a spin-coating technique. If the PR material being used has a significant inorganic component, for example, if it exhibits a framework predominantly composed of metal oxides, the underlayer is advantageously a carbon-based film and may be applied by either spin-coating or a dry, vacuum-based deposition process. This layer may include a variety of ashable hardmask (AHM) films with carbon-based and hydrogen-based compositions, and may be doped with additional elements such as tungsten, boron, nitrogen, or fluorine.

[0187] In some embodiments, a surface activation operation may be used to activate a surface (e.g., a surface of a substrate and / or film) for future operations. For example, SiO x For surfaces, water or oxygen / hydrogen plasma may be used to generate hydroxyl groups on the surface. For carbon-based or hydrocarbon-based surfaces, various treatments (water, hydrogen / oxygen, CO2 plasma, or ozone treatment) may be used to generate carboxylic acid and / or hydroxyl groups. Such approaches may prove important for improving adhesion of resist features to the substrate, which may otherwise peel or lift off during handling or in solvents during development.

[0188] Adhesion can also be enhanced by introducing roughness into the surface to increase the surface area available for interaction and directly improve mechanical adhesion. For example, a sputtering process using Ar or other non-reactive ion bombardment can first be used to create a rough surface. The surface can then be terminated with the desired surface functional groups (e.g., hydroxyl and / or carboxylic acid groups) as described above. On carbon, a combination approach can be used, in which a chemically reactive oxygen-containing plasma (such as CO, O, or H, O (or a mixture of H and O)) can be used to etch away a thin layer of the film with localized inhomogeneities while simultaneously terminating with -OH, -OOH, or -COOH groups. This can be performed with or without bias. In conjunction with the surface modification strategies described above, this approach can serve the dual purpose of roughening the surface and chemically activating the substrate surface for direct adhesion to inorganic metal oxide-based resists or as an intermediate surface modification for further functionalization.

[0189] In various embodiments, the surface (e.g., of a substrate and / or film) comprises exposed hydroxyl groups on the surface. Generally, the surface can be any surface that comprises, or has been treated to produce, an exposed hydroxyl surface. Such hydroxyl groups can be formed on the surface by surface treatment of the substrate with oxygen plasma, water plasma, or ozone. In other embodiments, the surface of the film can be treated to provide exposed hydroxyl groups, onto which a capping layer can be applied. In various embodiments, the hydroxy-terminated metal oxide layer has a thickness of 0.1 nm to 20 nm, or 0.2 nm to 10 nm, or 0.5 nm to 5 nm.

[0190] EUV exposure processing EUV exposure of the film can provide EUV-exposed regions with activated reactive centers containing a metal atom (M), which are generated by EUV-induced cleavage events. Such reactive centers can include dangling metal bonds, M-H groups, cleaved M-ligand groups, dimerized M-M bonds, or M-O-M crosslinks. In other embodiments, EUV exposure provides crosslinked organic moieties by photopolymerizing ligands within the film, or EUV exposure releases gas byproducts resulting from photolysis of bonds within the ligands.

[0191] The EUV exposure may have a wavelength in the range of about 10 nm to about 20 nm (e.g., a wavelength of 10 nm to 15 nm (e.g., 13.5 nm) in a vacuum atmosphere. In particular, patterning can provide EUV-exposed and non-EUV-exposed regions to form a pattern.

[0192] The present techniques include patterning using not only EUV but also DUV or electron beam radiation. In such patterning, radiation is focused onto one or more regions of the imaging layer. Exposure is typically performed such that the imaging layer film includes one or more regions that are not exposed to radiation. The resulting imaging layer may include multiple exposed and unexposed regions to create a pattern consistent with the creation of transistors or other features of a semiconductor device formed by adding or removing material from the substrate during subsequent processing of the substrate. EUV, DUV, and electron beam radiation methods and apparatus useful herein include well-known methods and apparatus.

[0193] In some EUV lithography techniques, an organic hard mask (e.g., a PECVD amorphous hydrogenated carbon ashable hard mask) is patterned. During photoresist exposure, EUV radiation is absorbed by the resist and the underlying substrate, generating high-energy photoelectrons (e.g., about 100 eV) and then a cascade of lower-energy secondary electrons (e.g., about 10 eV) that diffuse laterally a few nanometers. These electrons enhance the rate of chemical reactions in the resist that enhance EUV dose sensitivity. However, a secondary electron pattern, which is random in nature, is superimposed on the optical image. This unwanted secondary electron exposure causes reduced resolution, observable line-edge roughness (LER), and linewidth variations in the patterned resist. These defects are then carried over to the patterned material during subsequent pattern-transfer etching.

[0194] Disclosed herein is a vacuum-integrated metal hard mask process and associated vacuum-integrated hardware that combines film formation (evaporation / condensation) with optical lithography, resulting in significantly improved performance (e.g., reduced line edge roughness) in Extreme Ultraviolet (EUVL).

[0195] In various embodiments described herein, a deposition (e.g., condensation) process (e.g., ALD or MOCVD performed in a PECVD tool such as a Lam Vector®, or a spin-on process) can be used to form a thin film of a metal-containing film, such as a photosensitive metal salt or metal-containing organic compound (organometallic compound), that has a strong absorption in EUV (e.g., wavelengths on the order of 10 nm to 20 nm) at the wavelength of an EUVL source (e.g., 13.5 nm = 91.8 eV). This film photodecomposes upon EUV exposure to form a metal mask, which is a pattern transfer layer, during subsequent etching (e.g., in a conductor etching tool such as a Lam 2300® Kiyo®).

[0196] After deposition, the EUV-patternable thin film is patterned by exposure to a beam of EUV light, typically under a relatively high vacuum. The metal-containing film can then be deposited in a chamber integrated with the lithography platform (e.g., a wafer stepper such as the TWINSCAN NXE:3300B® manufactured by ASML, Veldhoven, The Netherlands) and transferred under vacuum to prevent reaction prior to exposure. Integration with a lithography tool is facilitated by the fact that EUVL also requires very low pressures, given the strong optical absorption of incident photons by ambient gases (e.g., H2O, O2). In other embodiments, photosensitive metal film deposition and EUV exposure can be performed in the same chamber. In yet other embodiments, photosensitive metal film deposition and EUV exposure can be performed in different chambers.

[0197] Development processes including wet development The EUV-exposed or unexposed regions can be removed by any useful development process. In one embodiment, the EUV-exposed regions can have activated reactive centers, such as dangling metal bonds, M-H groups, or dimerized M-M bonds. In certain embodiments, M-M groups can be selectively removed using one or more development processes. In other embodiments, M-M bonds can be selectively removed using a wet development process (e.g., to form soluble M(OH) n The EUV-exposed regions can be selectively removed (e.g., using hot ethanol and water to provide groups). In yet other embodiments, the EUV-exposed regions are removed using wet development (e.g., using a positive-tone developer). In some embodiments, the EUV-unexposed regions are removed using wet development (e.g., using a negative-tone developer).

[0198] In some embodiments, dry and wet operations may be combined to provide a dry / wet process. For any of the processes described herein (e.g., lithography processes, deposition processes, EUV exposure processes, development processes, pre-processing, post-coating processes, etc.), various specific operations may include wet, dry, or wet / dry embodiments. For example, wet deposition may be combined with wet development, or dry deposition may be combined with wet development. Any of these may also be combined with wet or dry pre- and post-coating processes described herein.

[0199] In certain embodiments, a wet development method may be utilized. In certain embodiments, such a wet development method is used to remove EUV-exposed regions to provide a positive-tone photoresist or a negative-tone resist. Non-limiting examples of wet development may include the use of alkaline developers (e.g., aqueous alkaline developers), such as those containing ammonium (e.g., ammonium hydroxide (NH4OH)), ammonium-based ionic liquids (e.g., tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), or other quaternary alkylammonium hydroxides), organic amines such as mono-, di-, and tri-organoamines (e.g., diethylamine, diethylamine, ethylenediamine, triethylenetetramine), or alkanolamines (e.g., monoethanolamine, diethanolamine, triethanolamine, or diethyleneglycolamine). In other embodiments, the alkaline developer may be a nitrogen-containing base (e.g., a compound represented by the chemical formula R N1 NH2, R N 1R N2 N.H., R. N1 R N2 R N3 N or R N1 R N2 R N3 R N4 N + X N1- a compound having the formula:N1 , R N2 , R N 3, and R N4 are each independently an organic substituent (e.g., optionally substituted alkyl or any of the substituents described herein) or two or more organic substituents that can be combined; N1- OH - , F - , Cl - , Br - , I - or other quaternary ammonium cation species known to those skilled in the art. These bases may also include heterocyclyl nitrogen compounds, some of which are described herein.

[0200] Other development methods can include the use of acidic developers (e.g., aqueous acidic developers or acidic developers in organic solvents) containing halides (e.g., HCl or HBr), organic acids (e.g., formic acid, acetic acid, or citric acid), or organic fluorine compounds (e.g., trifluoroacetic acid), or the use of organic developers (ketones (e.g., 2-heptanone, cyclohexanone, or acetone), esters (e.g., γ-butyrolactone or ethyl 3-ethoxypropionate (EEP)), alcohols (e.g., isopropyl alcohol (IPA)), or ethers (glycol ethers (e.g., propylene glycol methyl ether (PGME) or propylene glycol methyl ether acetate (PGMEA))), and combinations thereof.

[0201] In certain embodiments, the positive tone developer is an aqueous alkaline developer (e.g., including NHOH, TMAH, TEAH, TPAH, or TBAH). In other embodiments, the negative tone developer is an aqueous acidic developer, an acidic developer in an organic solvent, or an organic developer (e.g., HCl, HBr, formic acid, trifluoroacetic acid, 2-heptane, IPA, PGME, PGMEA, or combinations thereof).

[0202] Post-application treatment The methods herein may include any useful post-application treatment, as described below.

[0203] In backside and bevel cleaning processes, the vapor and / or plasma can be limited to specific areas of the wafer to ensure that only the backside and bevel are removed without causing any degradation of the film on the frontside of the wafer. The deposited EUV photoresist film being removed is typically composed of Sn, O, and C, but the same cleaning approach can be extended to films of other metal oxide resists and materials. Additionally, this approach can be used for film stripping and PR correction.

[0204] Suitable process conditions for dry bevel edge and backside cleaning may be 100 sccm to 500 sccm of reactant flow (e.g., 500 sccm of HCl, HBr, or H with Cl or Br, BCl, or H) for a period of about 10 seconds to 20 seconds, depending on the photoresist film and composition and properties, a temperature of −10° C. to 120° C. (e.g., 20° C.), a pressure of 20 mTorr to 500 mTorr (e.g., 300 mTorr), and a plasma power of 0-500 W at high frequency (e.g., 13.56 MHz). These conditions are suitable for some process reactors (e.g., Kiyo etch tools manufactured by Lam Research, Fremont, California), but it should be understood that a wider range of process conditions may be utilized depending on the capabilities of the process reactor.

[0205] Photolithography processing typically includes one or more bake steps to promote the chemical reactions necessary to create chemical differences between exposed and unexposed areas of the photoresist. In high-volume manufacturing (HVM), such bake steps are typically performed on a track where wafers are baked on a hotplate at a preset temperature under ambient air or, in some cases, N2 flow. More careful control of the bake atmosphere, as well as the introduction of additional reactive gas components into the atmosphere during these bake steps, can help further reduce the required dose and / or improve pattern fidelity.

[0206] According to various aspects of the present disclosure, one or more post-treatments on metal and / or metal oxide based photoresists after deposition (e.g., post-apply bake (PAB)) and / or after exposure (e.g., post-exposure bake (PEB)) and / or after development (e.g., post-develop bake (PDB)) can increase the difference in material properties between exposed and unexposed photoresists, thus reducing dose-to-size (DtS), improving PR profiles, and improving line edge roughness and line width roughness (LER / LWR) after subsequent development.

[0207] For post-application processing (e.g., PAB), thermal treatments can be used in conjunction with temperature, gas atmosphere (e.g., air, HO, CO, CO, O, O, CH, CHOH, N, H, NH, NO, NO, Ar, He, or mixtures thereof) or vacuum, and humidity control to alter the composition of unexposed metal and / or metal oxide photoresists after deposition and before exposure. Such alterations can increase the EUV sensitivity of the material, so that lower dose-to-size and edge roughness can be achieved after exposure and development.

[0208] For post-exposure processing (e.g., PEB), thermal treatment can be used with control of temperature, gas atmosphere (e.g., air, HO, CO, CO, O, O, CH, CHOH, N, H, NH, NO, NO, Ar, He, or mixtures thereof) or vacuum, and humidity to alter the composition of both the unexposed and exposed photoresist. The alteration can increase the difference in composition / material properties between the unexposed and exposed photoresist and the difference in development rate between the unexposed and exposed photoresist. A higher development selectivity can be achieved, thereby. The improved selectivity can result in a more square PR profile, along with improved surface roughness and / or less photoresist residue / scum. In certain embodiments, PEB can be performed in air, optionally with water vapor and CO.

[0209] For post-development treatments (e.g., post-develop bake, or PDB), thermal treatments can be used in conjunction with control of temperature, gas atmosphere (e.g., air, HO, CO, CO, O, O, CH, CHOH, N, H, NH, NO, NO, Ar, He, or mixtures thereof) or under vacuum (e.g., with UV), and humidity to alter the composition of the unexposed photoresist. In certain embodiments, the conditions further include the use of plasma (e.g., containing O, O, Ar, He, or mixtures thereof). The alteration can increase the hardness of the material, which can be useful when the film is used as a resist mask when etching an underlying substrate.

[0210] In these cases, in another embodiment, the thermal treatment may be replaced with a remote plasma treatment to increase the reactive species, thereby lowering the energy barrier for the reaction and increasing productivity. Remote plasma generates more reactive radicals, which may allow the reaction temperature / time of the treatment to be reduced, leading to increased productivity.

[0211] Therefore, one or more treatments may be applied to modify the photoresist itself to increase the development selectivity: for example, thermal or radical modification may increase the difference between unexposed and exposed material, thus increasing the selectivity of the subsequent development step.

[0212] While not wishing to be limited by mechanism, wet development can be dependent on material solubility, such that heating above 220°C, for example, can significantly increase the degree of cross-linking in both exposed and unexposed regions of the metal-containing PR film, such that both regions are insoluble in the wet development solvent, and as a result, the film can no longer be reliably wet-developed. For example, a PAB, PEB, etc. bake may be performed on a wet-spin-on or wet-developed metal-containing PR film at a temperature below 180°C, or below 200°C, or below 250°C, for example. The processing temperature for the PAB, PEB, or PDB may be varied over a window (e.g., for the PAB, PEB, and / or PDB) to adjust and optimize the processing process, for example, from about 90°C to 250°C (e.g., 90°C to 190°C), 90°C to 600°C, 100°C to 400°C, 125°C to 300°C, and from about 170°C to above 250°C (e.g., 190°C to 240°C). It has been found that increasing the processing temperature within the above ranges results in a decrease in etch rate and an increase in etch selectivity.

[0213] In certain embodiments, the PAB, PEB, and / or PDB processes may be performed at a gas atmosphere flow rate ranging from 100 sccm to 10,000 sccm, a humidity of a few percent up to 100% (e.g., 20% to 50%), a pressure between atmospheric pressure and vacuum, and a duration of about 1 to 15 minutes (e.g., about 2 minutes).

[0214] These findings can be used to adjust process conditions to tailor or optimize the process for specific materials and environments. For example, the selectivity achieved for a given EUV dose with a PEB thermal treatment at 220°C to 250°C in air with approximately 20% humidity for approximately 2 minutes can be comparable to the selectivity achieved for approximately 30% higher EUV doses without such a thermal treatment. Thus, depending on the selectivity requirements / constraints of a semiconductor processing operation, thermal treatments such as those described herein can be used to reduce the required EUV dose. Alternatively, when higher selectivity is required and a higher dose can be tolerated, much higher selectivity (up to 100x higher selectivity of exposed to unexposed regions) can be achieved than is possible in the context of wet development.

[0215] Still other steps may include in-situ measurements that can assess physical and structural features (e.g., critical dimensions, film thickness, etc.) during photolithography processing. Modules for achieving in-situ measurements include, for example, scatterometers, polarimetry, downstream mass spectrometry, and / or plasma-enhanced downstream optical emission spectroscopy modules.

[0216] Device The present disclosure also includes any apparatus configured to perform any of the methods described herein. In one embodiment, an apparatus for depositing a film includes a deposition module with a chamber for depositing an EUV-sensitive material as a film by providing a metal precursor, optionally in the presence of a counter reactant, a patterning module with an EUV photolithography tool having a radiation source at a wavelength less than 30 nm, and a development module with a chamber for developing the film in the presence of a metal chelator.

[0217] The apparatus may further include a controller having instructions for such modules. In one embodiment, the controller includes one or more memory devices, one or more processors, and system control software encoded with instructions for performing film deposition. Such including may include depositing a metal precursor as a film on the top surface of a substrate or photoresist layer in a deposition module, patterning the film directly with EUV exposure at a resolution of less than 30 nm in a patterning module to form a pattern in the film, and developing the film in the presence of a metal chelator in a development module. In certain embodiments, the development module provides removal of EUV-exposed or non-EUV-exposed regions, thereby providing a pattern in the film.

[0218] FIG. 4 illustrates one embodiment of a multi-station processing tool 400 (such as a VECTOR® processing tool manufactured by Lam Research, Fremont, California). The processing stations may be configured as modules within the cluster tool. FIG. 6 illustrates a semiconductor processing cluster tool architecture with vacuum-integrated deposition and patterning modules suitable for implementing embodiments described herein. Such a cluster processing tool architecture may include modules for resist deposition, resist exposure (EUV scanner), resist development, and etching, as described herein with reference to FIGS. 5 and 6.

[0219] In some embodiments, some of the processing functions may be performed sequentially in the same module. Thus, embodiments of the present disclosure are directed to methods and apparatus for receiving a wafer including a photopatterned EUV resist thin film layer disposed on a layer or layer stack to be etched after photopatterning in an EUV scanner, as described herein, into a development / etch chamber (e.g., a wet development / etch chamber), developing the photopatterned EUV resist thin film layer, and then etching an underlying layer using the patterned EUV resist as a mask.

[0220] The wet development chamber can be any chamber configured to supply a developer to an exposed film or substrate. In one example, the chamber can contain a wet developer therein, and the exposed film or substrate is immersed in the wet developer (e.g., in immersion development, etc.). In another example, the chamber can include one or more showerheads, sprays, nozzles, dispensers, etc. to supply the wet developer to the exposed film or substrate (e.g., in spray-on development, etc.).

[0221] A substrate may then be provided in the chamber and placed on the pedestal. For example, the substrate may be positioned below the dispenser and rest on the pedestal. In some embodiments, the pedestal may be raised or lowered to expose the substrate to the space between the substrate and the showerhead. Additionally, the pedestal may be rotated during the dispensing of the wet developer. Accordingly, in some embodiments, the pedestal may include a rotation axis for rotating the substrate. It will be appreciated that in some embodiments, one or more of these example adjustments may be programmatically performed by one or more suitable computer controllers.

[0222] As described above, one or more processing stations may be included in a multi-station processing tool. FIG. 4 is a schematic diagram illustrating one embodiment of a multi-station processing tool 400 including an entry load lock 402 and an exit load lock 404, one or both of which may be equipped with a remote plasma source. A robot 406 at atmospheric pressure is configured to move wafers from a cassette loaded through a pod 408 into the entry load lock 402 through an atmospheric port 410. The wafer is placed on a pedestal 412 in the entry load lock 402 by the robot 406, the atmospheric port 410 is closed, and the load lock is pumped down. If the entry load lock 402 is equipped with a remote plasma source, the wafer may undergo a remote plasma treatment to treat the silicon nitride surface within the load lock before being introduced into the processing chamber 414. Additionally, the wafer may be heated within the entry load lock 402, for example, to remove moisture and adsorbed gases. The chamber transfer port 416 to the processing chamber 414 is then opened and another robot (not shown) loads the wafer into the reactor and places it on the pedestal of the first station shown within the reactor for processing. While the embodiment shown in Figure 4 includes a load lock, it will be appreciated that in some embodiments, the wafer may be loaded directly into the processing station.

[0223] The illustrated processing chamber 414 includes four processing stations, numbered 1 through 4, in the embodiment shown in FIG. 4. Each station includes a heated pedestal (designated 418 for station 1) and a gas line inlet. It is understood that in some embodiments, each processing station may have a different purpose or multiple purposes. While the illustrated processing chamber 414 includes four stations, it is understood that processing chambers according to the present disclosure may have any suitable number of stations. For example, in some embodiments, a processing chamber may have five or more stations, while in other embodiments, a processing chamber may have three or fewer stations.

[0224] FIG. 4 illustrates one embodiment of a wafer handling system 490 for moving wafers within the processing chamber 414. In some embodiments, the wafer handling system 490 may move wafers between various processing stations and / or between processing stations and load locks. It is understood that any suitable wafer handling system may be used. Non-limiting examples include a wafer carousel and a wafer handler robot. FIG. 4 also illustrates one embodiment of a system controller 450 used to control the processing conditions and hardware status of the processing tool 400. The system controller 450 may include one or more memory devices 456, one or more mass storage devices 454, and one or more processors 452. The processor 452 may include a CPU or computer, analog and / or digital input / output connections, a stepper motor controller board, etc.

[0225] In some embodiments, the system controller 450 controls all operations of the processing tool 400. The system controller 450 executes system control software 458 stored on the mass storage device 454, loaded into the memory device 456, and executed by the processor 452. Alternatively, control logic may be hard-coded into the controller 450. Application-specific integrated circuits, programmable logic devices (e.g., field-programmable gate arrays, or FPGAs), or the like may be used for these purposes. Hereinafter, where "software" or "code" is used, functionally equivalent hard-coded logic may be used instead. The system control software 458 may comprise instructions for controlling the timing, mixture of gases, gas flow rates, chamber and / or station pressure, chamber and / or station temperature, wafer temperature, target power levels, RF power levels, substrate pedestal, chuck, and / or susceptor position, and other parameters of a particular process being performed by the processing tool 400. The system control software 458 may be configured in any suitable manner. For example, various process tool component subroutines or control objects may be written to control the operation of the process tool components used to perform the processes of the various process tools. The system control software 458 may be coded in any suitable computer-readable programming language.

[0226] In some embodiments, the system control software 458 may comprise input / output control (IOC) sequence instructions for controlling the various parameters described above. Other computer software and / or programs stored on the mass storage device 454 and / or memory device 456 associated with the system controller 450 may also be used in some embodiments. Examples of programs or program sections for this purpose include a substrate positioning program, a process gas control program, a pressure control program, a heater control program, and a plasma control program.

[0227] The substrate positioning program may comprise program code for processing tool components used to load a substrate onto the pedestal 418 and control the spacing between the substrate and other parts of the processing tool 400 .

[0228] The process gas control program may include code for controlling the composition (e.g., HBr or HCl gas, as described herein) and flow rates of various gases, and optionally for flowing gases into one or more process stations prior to deposition to stabilize the pressure within the process stations. The pressure control program may include code for controlling the pressure within the process stations, for example, by adjusting throttle valves in the exhaust systems of the process stations, gas flow rates to the process stations, etc.

[0229] The heater control program may include code for controlling the current to a heating unit used to heat the substrate, or the heater control program may control the supply of a heat transfer gas (such as helium) to the substrate.

[0230] A plasma control program may comprise code for setting RF power levels applied to process electrodes in one or more process stations according to embodiments herein.

[0231] The pressure control program may comprise code for maintaining pressure within the reaction chamber according to embodiments herein.

[0232] In some embodiments, there may be a user interface associated with the system controller 450. The user interface may include a display screen (graphical software display of equipment and / or process conditions) and user input devices such as a pointing device, keyboard, touch screen, microphone, etc.

[0233] In some embodiments, the parameters adjusted by the system controller 450 may relate to process conditions. Non-limiting examples include process gas composition and flow rates, temperature, pressure, plasma conditions (such as RF bias power levels), etc. These parameters may be provided to the user in the form of a recipe and may be entered using a user interface.

[0234] Signals for monitoring the process may be provided by analog and / or digital input connections of the system controller 450 from various process tool sensors. Signals for controlling the process may be output at analog and digital output connections of the process tool 400. Non-limiting examples of process tool sensors that may be monitored include mass flow controllers, pressure sensors (such as pressure gauges), thermocouples, etc. Appropriately programmed feedback and control algorithms may be used with data from these sensors to maintain process conditions.

[0235] The system controller 450 may provide program instructions for carrying out the deposition processes described above. The program instructions may control various process parameters, such as DC power levels, RF bias power levels, pressure, temperature, etc. The instructions may control parameters for operating development and / or etching processes according to various embodiments described herein.

[0236] The system controller 450 typically includes one or more memory devices and one or more processors configured to execute instructions that cause the device to perform methods according to the disclosed embodiments. A machine-readable medium containing instructions for controlling processing operations according to the disclosed embodiments may be coupled to the system controller 450.

[0237] In some embodiments, the system controller 450 is part of a system, which may be part of the examples described above. Such systems may include semiconductor processing equipment, such as one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (e.g., wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling the operation of the system before, during, and after processing of semiconductor wafers or substrates. The electronics may be referred to as a “controller” and may control various components or subcomponents of the system. Depending on the processing conditions and / or type of system, the system controller 450 may be programmed to control any of the processes disclosed herein, such as supply of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid supply settings, position and motion settings, and wafer movement in and out of tools and other transfer tools and / or load locks connected or coupled to a particular system.

[0238] Generally, system controller 450 may be defined as electronic equipment having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application-specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions may be communicated to system controller 450 in the form of various individual settings (or program files) that define operational parameters for performing specific processes on or for semiconductor wafers or instructions for the system. The operational parameters, in some embodiments, may be part of a recipe defined by a process engineer to accomplish one or more process steps during processing of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0239] In some embodiments, the system controller 450 may be part of or connected to a computer that is integrated with, connected to, or otherwise networked with the system, or a combination thereof. For example, the system controller 450 may be in the “cloud” or may be all or part of a fab host computer system that can enable remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of a manufacturing operation, examine the history of past manufacturing operations, or examine trends or performance indicators from multiple manufacturing operations, to change parameters of a current process, set up processing steps according to a current process, or initiate a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system over a network (which may include a local network or the Internet). The remote computer may include a user interface that allows entry or programming of parameters and / or settings, which are communicated to the system from the remote computer. In some examples, the system controller 450 receives instructions in the form of data, where the instructions specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed as well as the type of tool that the system controller 450 is configured to interface with or control. Thus, as described above, the system controller 450 may be distributed, such as by having one or more separate controllers that are networked and operate toward a common purpose (such as the process and control described herein). One example of a distributed controller for such purposes is one or more integrated circuits on the chamber that communicate with one or more remotely located integrated circuits (e.g., located at the platform level or remotely as part of a remote computer) that cooperate to control the process in the chamber.

[0240] Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an ALD chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, an EUV lithography chamber (scanner) or module, a wet development chamber or module, and any other semiconductor processing system that may be associated with or utilized in the processing and / or manufacturing of semiconductor wafers.

[0241] As described above, depending on the processing step or steps being performed by the tool, the system controller 450 may communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, another controller, or tools used in material transport to carry containers of wafers to or from tool locations and / or load ports within a semiconductor fabrication factory.

[0242] In certain embodiments, an inductively coupled plasma (ICP) reactor is described herein, which may be suitable for etching operations suitable for practicing some embodiments. Although an ICP reactor is described herein, it should be understood that in some embodiments, a capacitively coupled plasma reactor may also be used.

[0243] 5 is a cross-sectional view of an inductively coupled plasma apparatus 500 suitable for performing certain embodiments or aspects of embodiments, such as etching, an example of such an apparatus is the Kiyo® reactor manufactured by Lam Research, Inc., Fremont, Calif. In other embodiments, other tools or tool types capable of performing the etching processes described herein may be used for implementation.

[0244] The inductively coupled plasma apparatus 500 includes an overall processing chamber structurally defined by a chamber wall 501 and a window 511. The chamber wall 501 may be fabricated from stainless steel or aluminum. The window 511 may be fabricated from quartz or other dielectric materials. An optional internal plasma grid 550 divides the overall processing chamber into an upper subchamber 502 and a lower subchamber 503. In most embodiments, the plasma grid 550 can be removed to utilize the chamber space formed by the subchambers 502 and 503. A chuck 517 is disposed within the lower subchamber 503 near the bottom inner surface. The chuck 517 is configured to receive and hold a semiconductor wafer 519 upon which etching and deposition processes are performed. The chuck 517 may be an electrostatic chuck for supporting the wafer 519 when the wafer is present. In some embodiments, an edge ring (not shown) surrounds the chuck 517 and has an upper surface that is substantially coplanar with the upper surface of the wafer 519 when the wafer is present on the chuck 517. The chuck 517 also includes an electrostatic electrode for chucking and dechucking the wafer 519. A filter and DC clamp power supply (not shown) may be provided for this purpose.

[0245] Other control systems for lifting the wafer 519 from the chuck 517 may also be provided. The chuck 517 may be charged using an RF power supply 523. The RF power supply 523 is connected to a matching network 521 through connection 527. The matching network 521 is connected to the chuck 517 through connection 525. Thus, the RF power supply 523 is connected to the chuck 517. In various embodiments, the bias power of the electrostatic chuck may be set to about 50 V or a different bias power depending on the process being performed in accordance with the disclosed embodiments. For example, the bias power may be between about 20 V and about 100 V, or between about 30 V and about 150 V.

[0246] The elements for plasma generation include a coil 533 disposed above the window 511. In some embodiments, a coil is not utilized in the disclosed embodiments. The coil 533 is fabricated from a conductive material and includes at least one complete turn. The example coil 533 shown in FIG. 5 includes three turns. A cross section of the coil 533 is symbolized, with the "X" coil extending from the front to the back of the page and the "●" coil extending from the back to the front of the page. The elements for plasma generation also include an RF power supply 541 configured to provide RF power to the coil 533. Generally, the RF power supply 541 is connected to a matching network 539 through connection 545. The matching network 539 is connected to the coil 533 through connection 543. In this manner, the RF power supply 541 is connected to the coil 533. An optional Faraday shield 549 is disposed between the coil 533 and the window 511. The Faraday shield 549 may be maintained in a spaced relationship relative to the coil 533. In some embodiments, the Faraday shield 549 is positioned directly above the window 511. In some embodiments, the Faraday shield is between the window 511 and the chuck 517. In some embodiments, the Faraday shield is not maintained in a spaced relationship with respect to the coil 533. For example, the Faraday shield may be directly below the window with no gap. The coil 533, the Faraday shield 549, and the window 511 are each configured to be substantially horizontal with respect to one another. The Faraday shield 549 may prevent metals or other species from depositing on the window 511 of the processing chamber.

[0247] Process gases may be flowed into the processing chamber through one or more main gas inlets 560 and / or one or more side gas inlets 570 disposed in the upper subchamber 502. Similarly, although not explicitly shown, similar gas inlets may be used to supply process gases to the capacitively coupled plasma processing chamber. A vacuum pump (e.g., a one- or two-stage mechanical dry pump and / or turbomolecular pump) 540 may be used to draw process gases from the processing chamber and maintain pressure within the processing chamber. For example, the vacuum pump may be used to evacuate the lower subchamber 503 during an ALD purge operation. A valve-controlled conduit may be used to fluidly connect the vacuum pump to the processing chamber and selectively control the application of the vacuum environment provided by the vacuum pump. This may be done using a closed-loop controlled flow restriction device, such as a throttle valve (not shown) or a pendulum valve (not shown), during operating plasma processing. Similarly, a vacuum pump and a valve-controlled fluid connection to the capacitively coupled plasma processing chamber may be used.

[0248] During operation of the apparatus 500, one or more process gases may be supplied through the gas inlets 560 and / or 570. In certain embodiments, process gases may be supplied only through the main gas inlet 560 or only through the side gas inlet 570. In some cases, the gas inlets shown in the figure may be replaced with more complex gas inlets, such as one or more showerheads. The Faraday shield 549 and / or the optional grid 550 may include internal channels and holes that allow process gases to be delivered to the processing chamber. One or both of the Faraday shield 549 and the optional grid 550 may function as showerheads for the delivery of process gases. In some embodiments, a liquid vaporization / delivery system may be located upstream of the processing chamber such that liquid reactants or precursors are vaporized and the vaporized reactants or precursors are introduced into the processing chamber via the gas inlets 560 and / or 570.

[0249] Radio frequency power is supplied from RF power source 541 to coil 533, causing an RF current to flow through coil 533. The RF current flowing through coil 533 generates an electromagnetic field around coil 533. The electromagnetic field generates an induced current within upper subchamber 502. Physical and chemical interactions of the various ions and radicals generated with wafer 519 etch features in wafer 519 and selectively deposit layers on wafer 519.

[0250] When a plasma grid 550 is utilized such that both an upper subchamber 502 and a lower subchamber 503 are present, induced currents act on the gas present in the upper subchamber 502 to generate an electron-ion plasma within the upper subchamber 502. The optional internal plasma grid 550 limits the amount of hot electrons within the lower subchamber 503. In some embodiments, the apparatus 500 is designed and operated such that the plasma present in the lower subchamber 503 is an ion-ion plasma.

[0251] Both the upper electron-ion plasma and the lower ion-ion plasma contain positive and negative ions, but the ion-ion plasma has a higher ratio of negative ions to positive ions. Volatile etching and / or deposition byproducts may be removed from the lower subchamber 503 through port 522. The chuck 517 disclosed herein may be operated at elevated temperatures ranging from about 10° C. to about 250° C. The temperature depends on the processing operation and the particular recipe.

[0252] The tool 500 may be connected to equipment (not shown) when installed in a clean room or manufacturing facility. The equipment includes plumbing for providing process gases, vacuum, temperature control, and environmental particle control. These equipment will be connected to the tool 500 when installed in the target manufacturing facility. Additionally, the tool 500 may be connected to a transfer chamber that allows semiconductor wafers to be transferred in and out of the tool 500 using robotic techniques, using typical automation.

[0253] In some embodiments, a system controller 530 (which may include one or more physical or logical controllers) controls some or all of the operation of the processing chamber. The system controller 530 may include one or more memory devices and one or more processors. In some embodiments, the apparatus 500 includes a switching system for controlling flow rates and durations when the disclosed embodiments are performed. In some embodiments, the apparatus 500 may have a switching time of up to about 600 ms or up to about 750 ms. The switching time may depend on the flow chemistry, the selected recipe, the reactor architecture, and other factors.

[0254] In some embodiments, the system controller 530 is part of a system, which may be part of the examples described above. Such a system may include semiconductor processing equipment, such as one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (e.g., wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling the operation of the system before, during, and after processing of semiconductor wafers or substrates. The electronics may be integrated into the system controller 530, which may control various components or subcomponents of the system. The system controller may be programmed to control any of the processes disclosed herein, such as supply of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid supply settings, position and motion settings, and wafer movement in and out of tools and other transfer tools and / or load locks connected or coupled to a particular system, depending on the process parameters and / or type of system.

[0255] Generally, the system controller 530 may be defined as electronic equipment having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application-specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). The program instructions may be communicated to the controller in the form of various individual settings (or program files) that define operational parameters for performing specific processes on or for semiconductor wafers or instructions for the system. The operational parameters, in some embodiments, may be part of a recipe defined by a process engineer to accomplish one or more process steps during the processing or removal of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of the wafer.

[0256] In some embodiments, the system controller 530 may be part of or connected to a computer that is integrated with, connected to, or otherwise networked with the system, or a combination thereof. For example, the controller may be in the “cloud” or may be all or part of a fab host computer system that can enable remote access for wafer processing. The computer may enable remote access to the system to monitor the current progress of a manufacturing operation, examine the history of past manufacturing operations, or examine trends or performance indicators from multiple manufacturing operations, to change parameters of a current process, set up processing steps according to a current process, or initiate a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system over a network (which may include a local network or the Internet). The remote computer may include a user interface that allows entry or programming of parameters and / or settings, which are communicated to the system from the remote computer. In some examples, the system controller 530 receives instructions in the form of data, where the instructions specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed as well as the type of tool the controller is configured to interface with or control. Thus, as described above, the system controller 530 may be distributed, such as by having one or more separate controllers that are networked and operate toward a common purpose (such as the process and control described herein). One example of a distributed controller for such purposes is one or more integrated circuits on the chamber that communicate with one or more remotely located integrated circuits (e.g., located at the platform level or remotely as part of a remote computer) that cooperate to control the process in the chamber.

[0257] Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an ALD chamber or module, an ALE chamber or module, an ion implantation chamber or module, a track chamber or module, an EUV lithography chamber (scanner) or module, a wet development chamber or module, and any other semiconductor processing system that may be associated with or utilized in the processing and / or manufacturing of semiconductor wafers.

[0258] As described above, depending on the processing step or steps being performed by the tool, the controller may communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, another controller, or tools used in material transport to carry containers of wafers to or from tool locations and / or load ports within a semiconductor fabrication factory.

[0259] EUVL patterning may be performed using any suitable tool (often referred to as a scanner), such as, for example, a TWINSCAN NXE:3300B® platform manufactured by ASML, Veldhoven, The Netherlands. The EUVL patterning tool may be a stand-alone apparatus into which substrates are loaded and unloaded for deposition and etching as described herein. Alternatively, as described below, the EUVL patterning tool may be a module on a larger, multi-component tool. FIG. 6 illustrates a semiconductor processing cluster tool architecture with a vacuum-integrated deposition module, an EUV patterning module, and a develop / etch module coupled to a vacuum transfer module, suitable for carrying out the processes described herein. While processes may be performed without utilizing such a vacuum-integrated apparatus, such an apparatus may be advantageous in some embodiments.

[0260] 6 illustrates a semiconductor processing cluster tool architecture with vacuum-integrated deposition and patterning modules coupled with a vacuum transfer module suitable for carrying out the processes described herein. The arrangement of multiple storage facilities and transfer modules that "transfer" wafers between processing modules is sometimes referred to as a "cluster tool architecture" system. The deposition and patterning modules are vacuum-integrated according to the requirements of a particular process. Other modules, such as for etching, may also be included in the cluster.

[0261] A vacuum transfer module (VTM) 638 interfaces with four processing modules 620a-620d, which may be individually optimized to perform various processing operations. For example, processing modules 620a-620d may be implemented to perform deposition, evaporation, ELD, development, etching, stripping, and / or other semiconductor processes. For example, module 620a may be an ALD reactor operable to perform thermal atomic layer deposition in a non-plasma environment as described herein, such as a Vector tool manufactured by Lam Research, Inc. of Fremont, California. And module 620b may be a PECVD tool, such as a Lam Vector®. It should be understood that the drawings are not necessarily drawn to scale.

[0262] Airlocks 642 and 646 (also known as load locks or transfer modules) connect VTM 638 and patterning module 640. For example, as mentioned above, a suitable patterning module can be a TWINSCAN NXE:3300B® platform manufactured by ASML of Veldhoven, The Netherlands. This tool architecture allows workpieces (such as semiconductor substrates or wafers) to be transferred under vacuum to prevent reaction prior to exposure. Integration of the deposition module with the lithography tool is facilitated by the fact that EUVL also requires very low pressures, given the strong optical absorption of incident photons by ambient gases (e.g., HO, O).

[0263] As noted above, this integrated architecture is only one possible embodiment of a tool for carrying out the described processes. The processes may be carried out by a stand-alone EUVL scanner and a deposition reactor (such as a Lam Vector tool) that is standalone or integrated as a module into a cluster architecture with other tools (e.g., a Lam Kiyo or Gamma tool) for etching, stripping, etc., as described with reference to FIG. 6, except that there is no integrated patterning module.

[0264] Airlock 642 may be an "outgoing" load lock, referring to the removal of substrates from VTM 638, which feeds deposition module 620a, to patterning module 640, and airlock 646 may be an "incoming" load lock, referring to the return of substrates from patterning module 640 to VTM 638. Incoming load lock 646 may also provide an interface outside the tool for accessing and unloading substrates. Each processing module has a facet that connects the module to VTM 638. For example, deposition processing module 620a has facet 636. Within each facet, sensors (e.g., sensors 1-18 in the figure) are used to detect the passage of wafer 626 as it is moved between its respective stations. Patterning module 640 and airlocks 642 and 646 may similarly include additional facets and sensors not shown.

[0265] A main VTM robot 622 transfers wafers 626 between modules, including airlocks 642 and 646. In one embodiment, the robot 622 has one arm, and in another embodiment, the robot 622 has two arms, each arm having an end effector 624 that grasps a wafer (such as wafer 626) for transfer. A front-end robot 644 is used to transfer wafers 626 from the output airlock 642 to the patterning module 640 and from the patterning module 640 to the input airlock 646. The front-end robot 644 may also transfer wafers 626 between the input load lock and the exterior of the tool for substrate access and removal. The input airlock module 646 can accommodate environments between atmosphere and vacuum, allowing wafers 626 to move between the two pressure environments without being damaged.

[0266] It should be noted that EUVL tools typically operate at a higher vacuum than deposition tools. In this case, it is preferable to increase the vacuum environment of the substrate during transfer from the deposition tool to the EUVL tool to allow the substrate to degas before entering the patterning tool. The unload airlock 642 provides this function by holding the transferred wafer at a lower pressure (below the pressure in the patterning module 640) for a period of time and evacuating all off-gassing so that the optics of the patterning tool 640 are not contaminated by off-gassing from the substrate. A suitable pressure for the unload off-gas airlock is 1E-8 Torr or less.

[0267] In some embodiments, a system controller 650 (which may include one or more physical or logical controllers) controls some or all of the operation of the cluster tool and / or its separate modules. Note that the controller may be located locally to the cluster structure or may be located outside of the cluster structure, i.e., at a remote location within the manufacturing floor, and connected to the cluster structure via a network. The system controller 650 may include one or more memory devices and one or more processors. The processor may include a central processing unit (CPU) or computer, analog and / or digital input / output connections, stepper motor controller boards, and other similar components. Instructions for implementing appropriate control operations are executed by the processor. These instructions may be stored in a memory device associated with the controller or provided over a network. In certain embodiments, the system controller executes system control software.

[0268] The system control software may comprise instructions for controlling the timing and / or extent of application of any aspect of tool or module operation. The system control software may be configured in any suitable manner. For example, various processing tool component subroutines or control objects may be written to control the operation of the processing tool components necessary to perform the various processing tool processes. The system control software may be coded in any suitable computer-readable programming language. In some embodiments, the system control software comprises input / output control (IOC) sequencing instructions for controlling the various parameters described above. For example, each step of a semiconductor manufacturing process may comprise one or more instructions for execution by the system controller. Instructions for setting process conditions for condensation, deposition, evaporation, patterning, and / or etching steps may be included in the corresponding recipe steps, for example.

[0269] In various embodiments, an apparatus for forming a negative pattern mask is provided. The apparatus may include process chambers for patterning, deposition, and etching, and a controller including instructions for forming the negative pattern mask. The instructions may include code for, in the process chamber, patterning features in a chemically amplified (CAR) resist on a semiconductor substrate by EUV exposure to expose a surface of the substrate, developing the photopatterned resist, and etching an underlying layer or underlying layer stack using the patterned resist as a mask.

[0270] It should be noted that the computer controlling the wafer movement may be located locally to the cluster architecture, or may be located outside or remotely from the cluster architecture within the manufacturing floor and connected to the cluster architecture via a network.

[0271] Conclusion Although the present embodiments have been described in some detail for purposes of clarity, it will be apparent that certain changes and modifications may be made within the scope of the appended claims. The embodiments disclosed herein may be practiced without some or all of these specific details. Additionally, detailed descriptions of well-known process operations have been omitted to avoid unnecessarily obscuring the disclosed embodiments. Furthermore, although the disclosed embodiments are described in connection with specific embodiments, it should be understood that the specific embodiments are not intended to limit the disclosed embodiments. It should be noted that there are many other ways to implement the processes, systems, and apparatuses of the present invention. Therefore, the present embodiments are considered to be illustrative and not limiting, and the embodiments are not limited to the details set forth herein.

Claims

1. 1. A method comprising: providing a radiation-patterned film having an interface region disposed between radiation-exposed and non-radiation-exposed regions or disposed within the radiation-exposed regions, the interface region comprising radiation-exposed metal centers; developing the radiation-patterned film in the presence of a metal chelating agent, the metal chelating agent configured to bind to the radiation-exposed metal centers in the interfacial region; A method comprising:

2. 10. The method of claim 1, wherein the radiation-patterned film comprises an extreme ultraviolet (EUV) sensitive film.

3. 3. The method of claim 2, wherein the interface region comprises a transition region disposed between at least one EUV exposed region and at least one EUV non-exposed region.

4. 3. The method of claim 2, wherein the developing step further comprises removing the interface region.

5. 3. The method of claim 2, wherein the developing step further comprises utilizing a solvent or solvent mixture that preferentially removes the radiation-exposed areas relative to the non-radiation-exposed areas.

6. 6. The method of claim 5, wherein the metal chelator is soluble in the solvent or solvent mixture.

7. 3. The method of claim 2, wherein the metal chelator preferentially binds to the radiation-exposed metal centers in the interface region relative to metal centers present in the non-radiation-exposed region.

8. 8. The method of claims 2-7, wherein the metal chelator comprises a dicarbonyl, diol, carboxylic acid, diacid, triacid, hydroxycarboxylic acid, hydroxamic acid, hydroxylactone, hydroxyketone, or a salt thereof.

9. 9. The method of claim 8, wherein the metal chelator comprises formic acid, citric acid, acetylacetone, salicylic acid, catechol, or ascorbic acid.

10. 9. The method of claim 8, wherein the dicarbonyl is a 1,3-diketone.

11. 9. The method of claim 8, wherein the carboxylic acid is R Ａ１ -CO ２ Contains H, R Ａ１ is H, optionally substituted alkyl, optionally substituted hydroxyalkyl, optionally substituted hydroxyaryl, optionally substituted carboxyalkyl, optionally substituted carboxyaryl, or optionally substituted aryl.

12. 9. The method of claim 8, wherein the hydroxamic acid is R Ａ１ -C(O)NR Ａ２ Contains OH, R Ａ１ and R Ａ２ each is independently H, optionally substituted alkyl, or optionally substituted aryl.

13. 9. The method of claim 8, wherein the hydroxyketone comprises a hydroxypyridinone, a hydroxypyrimidone, or a hydroxypyrone.

14. 9. The method of claim 8, wherein the hydroxyketone has a structure of the following formula (I), (II), or (III): 【Chemical 1】 、 【Chemistry 2】 、 【Chemistry 3】 、 or salts thereof, X １ and X ２ are each independently -CR １ = or -N=, Each R １ and R ２ are independently H, optionally substituted alkyl, optionally substituted hydroxyalkyl, optionally substituted carboxyalkyl, —C(O)NR Ｎ１ R Ｎ２ , or —C(O)OR Ｏ１ where R Ｎ１ , R Ｎ２ , and R Ｏ１ are independently H, optionally substituted alkyl, or optionally substituted alkyl, and optionally R Ｎ１ and R Ｎ２ collectively form an optionally substituted heterocyclyl, R ３ are independently H, optionally substituted alkyl, or optionally substituted aryl.

15. 8. The method of claims 2-7, wherein the metal chelator comprises a plurality of moieties disposed on a backbone, the plurality of moieties being selected from the group consisting of hydroxyl, carboxyl, amide, amino, and oxo.

16. 16. The method of claim 15, wherein the plurality of moieties comprises a dicarbonyl, diol, carboxylic acid, diacid, triacid, hydroxycarboxylic acid, hydroxamic acid, hydroxylactone, hydroxyketone, or salts thereof in mono- or polyvalent form.

17. 3. The method of claim 2, wherein the radiation-exposed metal center comprises a transition metal.

18. 3. The method of claim 2, wherein the radiation-exposed metal centers comprise tin (Sn), tellurium (Te), bismuth (Bi), antimony (Sb), or tantalum (Ta).

19. The method of claim 2 , wherein the radiation-patterned film comprises a metal oxide film or an organometallic oxide film.

20. 20. The method of claim 19, wherein the radiation-patterned film is formed from a metal precursor having a structure having the following chemical formula (IV): M ａ R ｂ (IV) where: M is a metal, each R is independently H, halo, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted alkoxy, optionally substituted alkanoyloxy, optionally substituted aryl, optionally substituted amino, optionally substituted bis(trialkylsilyl)amino, optionally substituted trialkylsilyl, oxo, anionic ligand, neutral ligand, or multidentate ligand; A method in which a≧1, b≧1.

21. 21. The method of claim 20, wherein M is tin (Sn), tellurium (Te), bismuth (Bi), antimony (Sb), tantalum (Ta), cesium (Cs), indium (In), molybdenum (Mo), or hafnium (Hf).

22. 3. The method of claim 2, wherein the developing step further comprises developing in the presence of two or more different metal chelating agents.

23. 10. The method of claim 1 further comprising: The method comprises, after the step of providing the radiation-patterned film, performing a post-exposure bake at a temperature of less than 180°C.

24. 10. The method of claim 1, wherein the step of providing a radiation-patterned film further comprises: providing a patterned radiation-sensitive film as a resist film; patterning the resist film by patterning radiation exposure to provide an exposed film having one or more radiation-exposed regions, one or more non-radiation-exposed regions, and an interfacial region disposed between at least one of the radiation-exposed regions and at least one of the non-radiation-exposed regions or disposed within the radiation-exposed regions; A method comprising:

25. 25. The method of claim 24, wherein the patterned radiation-sensitive film is provided by spin coating.

26. 25. The method of claim 24, further comprising: The method further comprises the step of performing a post-apply bake at a temperature below 180° C. prior to said patterning step.

27. A method of utilizing a resist, comprising: depositing a metal precursor onto a surface of a substrate to provide a patterned radiation-sensitive film as a resist film; patterning the resist film by patterning radiation exposure to provide an exposed film having one or more radiation-exposed regions, one or more non-radiation-exposed regions, and an interfacial region disposed between at least one of the radiation-exposed regions and at least one of the non-radiation-exposed regions or disposed within the radiation-exposed regions; developing the exposed film in the presence of a metal chelating agent and a solvent to remove the interfacial region and either the radiation-exposed or non-radiation-exposed areas to provide a pattern in the resist; A method comprising:

28. 28. The method of claim 27, wherein the patterning radiation-sensitive film comprises an extreme ultraviolet (EUV)-sensitive film.

29. 29. The method of claim 28, wherein the patterning radiation exposure comprises EUV exposure having a wavelength in the range of about 10 nm to about 20 nm in a vacuum atmosphere.

30. 30. The method of claim 28, wherein the pattern comprises reduced line edge roughness (LER) compared to a pattern developed without the metal chelating agent.

31. 29. The method of claim 28, wherein the metal chelator is configured to preferentially remove the interface region and the solvent is configured to preferentially remove either the radiation-exposed region or the radiation-unexposed region.

32. An apparatus for forming a resist film, a deposition module including a chamber for depositing a patterned radiation-sensitive film; a patterning module including a photolithography tool having a radiation source with a wavelength less than 300 nm; a developing module including a chamber for developing the resist film; a controller comprising one or more memory devices, one or more processors, and system control software coded with instructions; Equipped with The instruction: machine-readable instructions for depositing, in the deposition module, a metal precursor onto a top surface of a semiconductor substrate to form the patterned radiation-sensitive film as a resist film; machine-readable instructions for patterning, in the patterning module, the resist film directly by patterning radiation exposure with a resolution of less than 300 nm to form an exposed film having one or more radiation-exposed regions, one or more non-radiation-exposed regions, and an interface region disposed between at least one of the radiation-exposed regions and at least one of the non-radiation-exposed regions or disposed within the radiation-exposed region; machine-readable instructions for developing the exposed film in the presence of a metal chelating agent and a solvent in the developing module to remove the interfacial region and at least one of the radiation-exposed region or the radiation-unexposed region to provide a pattern in the resist film; 1. An apparatus comprising:

33. 33. The apparatus of claim 32, wherein the patterning radiation sensitive film comprises an extreme ultraviolet (EUV) sensitive film.

34. 34. The apparatus of claim 33, wherein the radiation source for the photolithography tool is a radiation source with a wavelength less than 30 nm.

35. 35. The apparatus of claim 34, wherein the machine-readable instructions further comprise: and instructions for, in the patterning module, patterning the resist film directly by EUV exposure with a resolution of less than 30 nm to form the exposed film having an EUV-exposed region, a non-EUV-exposed region, and the interface region located between at least one of the EUV-exposed region and the non-EUV-exposed region or within the EUV-exposed region.

36. 36. The apparatus of claim 35, wherein the machine-readable instructions further comprise: and instructions for developing the exposed film in the presence of the metal chelating agent and the solvent in the developing module to remove the interfacial region and at least one of the EUV-exposed region or the EUV-unexposed region to provide a pattern in the resist film.

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