Resist Composition

Abstract

The present invention relates to resist compostions, in particular to photoresists that can be used in photolithography, especially in the fabrication of integrated circuits and derivative products. The resist compositions of the invention include an anti-scattering component which has a significant amount of empty space, and thus fewer scattering centers, such that radiation-scattering events are more limited during exposure. Such anti-scattering effects can lead to improved resolutions by reducing the usual proximity effects associated with lithographic techniques, allowing the production of smaller, higher resolution microchips. Furthermore, certain embodiments involve anti-scattering components which are directly linked to the resist components, which can improve the overall lithographic chemistry to provide benefits both in terms of resolution and resist sensitivity.

1 - 27 . (canceled) 
     
     
         28 . A method of performing lithography, the method comprising:
 i) applying an antiscattering resist coating to a substrate;   ii) exposing part(s) of the antiscattering resist coating to radiation to provide an exposed antiscattering resist coating;   iii) developing the exposed antiscattering resist coating to generate an antiscattering resist pattern layer, the antiscattering resist pattern layer comprising: developer-insoluble coating portions of the antiscattering resist coating, and an array of grooves extending through the antiscattering resist pattern layer;   iv) optionally modifying the substrate, substrate surface, or part(s) thereof, underlying the antiscattering resist pattern layer;   v) optionally removing the antiscattering resist pattern layer to provide a modified substrate; and   vi) optionally repeating, one or more times, step iv) and/or steps i)-v) with either the antiscattering resist coating or an alternative resist coating, and optionally using alternative radiation during exposure upon the modified substrate,
 wherein step (i) of the method is optionally preceded by performing steps (i) to (vi), optionally repeated one or more times, using either the antiscattering resist coating or an alternative resist coating and optionally using alternative radiation during exposure; 
 wherein the antiscattering resist coating is an optionally dried and/or cured antiscattering resist coating composition; and 
 wherein the antiscattering resist coating composition comprises an antiscattering component, the antiscattering component comprising a polymetallic metal-organic complex comprising a primary metal complex that is a polymetallic cage and/or polymetallic ring system comprising a plurality of at least one type of metal ion interlinked via one or more bridging ligands, wherein the at least one type of metal ion excludes boron and silicon. 
   
     
     
         29 . The method as claimed in  claim 28 , wherein the substrate is an electronic component substrate (e.g. a silicon wafer), and the method produces an integrated circuit which is optionally incorporated into an integrated circuit package, a circuit board, and/or an electronic device or system. 
     
     
         30 . The method as claimed in  claim 28 , wherein the substrate is a lithographic mask substrate (e.g. a lithographic plate), and the method produces a lithographic mask, wherein the lithographic mask is a photomask with regions that are transparent to UV and/or visible light and regions that are non-transparent to UV and/or visible light. 
     
     
         31 . The method as claimed in  claim 30 , wherein the lithographic mask substrate is transparent to UV and/or visible light and the method comprises generating opaque regions on the lithographic mask substrate, whereby either non-removed antiscattering resist coating provides the opaque regions or else the opaque regions are generated by judicious surface modifications. 
     
     
         32 . The method as claimed in  claim 30 , wherein the lithographic mask substrate is non-transparent to UV and/or visible light and the method comprises generating transparent regions on the lithographic mask substrate, optionally by removing regions of opaque material to leave transparent regions. 
     
     
         33 . The method as claimed in  claim 30 , wherein the photomask is used to produce an integrated circuit which is optionally incorporated into an integrated circuit package, a circuit board, and/or an electronic device or system. 
     
     
         34 . The method as claimed in  claim 28 , wherein the antiscattering resist composition comprises a resist component, or one or more resist components, wherein either:
 a) the anti-scattering component is the resist component;   b) the anti-scattering component comprises the resist component such that the resist component is part of the anti-scattering component or is mutually associated or connected therewith, whether chemically and/or physically, by way of bonding; or   c) the resist component is a separate compound from the anti-scattering component.   
     
     
         35 . The method as claimed in  claim 28 , wherein the anti-scattering component either:
 has a density less than or equal to 1.6 g/cm 3 , and a molecular weight greater than or equal to 1000 g/mol; or   has a density less than or equal to 1.3 g/cm 3 , and a molecular weight greater than or equal to 2000 g/mol.   
     
     
         36 . The method as claimed in  claim 28 , wherein the primary metal complex comprises three or more moles of the metal species per mole of primary metal complex. 
     
     
         37 . The method as claimed in  claim 36 , wherein the primary metal complex is free of direct metal-metal bonds. 
     
     
         38 . The method as claimed in  claim 37 , wherein the primary metal complex comprises two or more different metal species (i.e. two or more different metal ions), M 1  and M 2 , wherein M 1  and M 2  are either derived from the same metal element but have a different valency or derived from a different metal element and have the same or a different valency. 
     
     
         39 . The method as claimed in  claim 38 , wherein at least one of M 1  and M 2  is a transition metal (d-block) species. 
     
     
         40 . The method as claimed in  claim 38 , wherein the molar ratio of M 1  to M 2  is between 10:1 and 2:1. 
     
     
         41 . The method as claimed in  claim 38 , wherein M 1  is selected from the group consisting of Cr III , Fe III , V III , Ga III , Al III , and In III . 
     
     
         42 . The method as claimed in  claim 38 , wherein M 2  is selected from the group consisting of Ni II , Co II , zn II , Cd II , Mn II , Mg II , Ca II , Sr II , Ba II , Cu II , and Fe II . 
     
     
         43 . The method as claimed in  claim 38 , wherein M 1  is Cr III  and M 2  is Ni II . 
     
     
         44 . The method as claimed in  claim 28 , wherein the primary metal complex comprises a mixture of two or more different types of ligand. 
     
     
         45 . The method as claimed in  claim 28 , wherein the primary metal complex comprises a carboxylate ligand, and wherein the carboxylate is a bridging ligand that provides a bridge between two or more metal ions. 
     
     
         46 . The method as claimed in  claim 28 , wherein the primary metal complex comprises a fluoro ligand. 
     
     
         47 . The method as claimed in  claim 28 , wherein the primary metal complex comprises a bifunctional ligand comprising coordinating atom(s) capable of forming an internal dative bond(s) with metal ions within the primary metal complex, and one or more additional coordinating atoms capable of forming external dative bonds. 
     
     
         48 . The method as claimed in  claim 47 , wherein the bifunctional ligand comprises a carboxylate group and an additional nitrogen-containing moiety. 
     
     
         49 . The method as claimed in  claim 28 , wherein the primary metal complex is defined by or comprises units defined by:
   [M 1   x M 2   y F 8 (O 2 CR B1 ) 16-b2 (O 2 CR B2 ) b2 ]   
       wherein:
 M 1  is a trivalent metal ion; 
 M 2  is a divalent metal ion; 
 x is 6, 7, 8, or 9; 
 y is 0, 1, or 2; 
 R B1  is an optionally substituted hydrocarbyl moiety, suitably a hydrocarbyl moiety devoid of basic or chelating groups, suitably an optionally substituted (1-20C)hydrocarbyl group comprising a π-system, suitably selected from (1-12C)alkyl, (1-12C)alkenyl, (1-12C)alkynyl, (3-8C)cycloalkyl, (3-8C)cycloalkenyl, (1-3C)alkyl(3-8C)cycloalkyl, (1-3C)alkyl(3-8C)cycloalkenyl, aryl, (1-3C)alkylaryl, aryl(1-3C)alkyl; 
 R B2  is a group comprising a basic or chelating group (e.g. a moiety with a lone pair of electrons that is free to co-ordinate to form a dative bond), and is selected from optionally substituted heterocyclyl, heteroaryl, heterocyclyl(1-6C)alkyl, heteroaryl(1-6C)alkyl, or is selected from (1-12C)alkyl, (1-12C)alkenyl, (1-12C)alkynyl, (3-8C)cycloalkyl, (3-8C)cycloalkenyl, (1-3C)alkyl(3-8C)cycloalkyl, (1-3C)alkyl(3-8C)cycloalkenyl, aryl, (1-3C)alkylaryl, or aryl(1-3C)alkyl, substituted with one or more basic or chelating groups, for example, amino, alkylamino, dialkylamino, hydroxyl, (1-6C)alkoxy, carbonyl, immino, thio, thiocarbonyl; and 
 b2 is 0, 1, 2, or 3; 
 wherein the sum of x and y is 7, 8, 9, or 10 (most suitably 8). 
 
     
     
         50 . The method as claimed in  claim 28 , wherein the primary metal complex is defined by or comprises units defined by the Formula IIa:
   [M 1   8-y M 2   y F 8 (O 2 CR B1 ) 16-b2 (O 2 CR B2 ) b2 ]   
       wherein:
 M 1  is a trivalent metal ion; 
 M 2  is a divalent metal ion; 
 y is 0 or 1; 
 R B1  is a group devoid of basic or chelating group and is selected from (1-12C)alkyl, (1-12C)alkenyl, (1-12C)alkynyl, (3-8C)cycloalkyl, (3-8C)cycloalkenyl, (1-3C)alkyl(3-8C)cycloalkyl, (1-3C)alkyl(3-8C)cycloalkenyl, aryl, (1-3C)alkylaryl, aryl(1-3C)alkyl; 
 R B2  is a group comprising a basic or chelating group (e.g. a moiety with a lone pair of electrons that is free to co-ordinate to form a dative bond) and is selected from optionally substituted heterocyclyl, heteroaryl, heterocyclyl(1-6C)alkyl, heteroaryl(1-6C)alkyl, or is selected from (1-12C)alkyl, (1-12C)alkenyl, (1-12C)alkynyl, (3-8C)cycloalkyl, (3-8C)cycloalkenyl, (1-3C)alkyl(3-8C)cycloalkyl, (1-3C)alkyl(3-8C)cycloalkenyl, aryl, (1-3C)alkylaryl, or aryl(1-3C)alkyl, substituted with one or more basic or chelating groups, for example, amino, alkylamino, dialkylamino, hydroxyl, (1-6C)alkoxy, carbonyl, immino, thio, thiocarbonyl; and 
 b2 is 0, 1, 2, or 3. 
 
     
     
         51 . The method as claimed in  claim 28 , wherein the primary metal complex is defined by or comprises units defined by the Formula IIf:
   [M 1   x M 2   y (O 2 CR B1 ) r ];   wherein M 1  is a first metal species and x is the number of moles of M 1  per mole of primary metal complex (suitably x is a number between 4 and 10); M 2  is a second metal species and y is the number of moles of M 2  per mole of primary metal complex (suitably y is a number between 0 and 2); wherein R B1  is an optionally substituted (1-20C)hydrocarbyl group comprising a π-system, suitably a terminal π-system; wherein r is an integer having a value of 1 or greater (suitably between 1 and 16); and wherein the units of Formula IIf optionally comprise one or more other associated ligands (i.e. datively bound within the complex).   
     
     
         52 . The method as claimed in  claim 28 , wherein the primary metal complex comprises one or more resist ligands datively bonded to the metal ions thereof, each resist ligand bearing a cross-linkable π-system and one or more co-ordination donor atoms or groups, wherein:
 the π-system is selected from the group including: a carbon-carbon double bond or triple bond; a carbon-heteroatom double bond or triple bond; an aromatic or heteroaromatic ring system; a conjugated π-system involving carbon and optionally heteroatom(s); or a mixture thereof; and 
 the one or more co-ordination donor atoms or groups comprise one or more lone-pair bearing heteroatoms. 
 
     
     
         53 . The method as claimed in  claim 52 , wherein each resist ligand is independently selected from the group consisting of an optionally substituted: alkenoate, alkenoic acid, alkenoic ester, alkenoic amide, alkynoate, alkynoic acid, alkynoic ester, alkynoic amide, (2-20C)alkenoate, (2-20C)alkenoic acid, (2-20C)alkenoic ester, (2-20C)alkenoic amide, or a mixture thereof, such that the resist ligand comprises at least one terminal alkene moiety. 
     
     
         54 . The method as claimed in  claim 28 , wherein the antiscattering resist composition comprises a secondary electron generator, SEG, which is a compound or component characterised by either having a Z eff  greater than or equal to 25, or by comprising a metal species having an atomic number (Z) greater than or equal to 49 and having an oxidation state of +1 or higher, wherein the secondary electron generator is either:
 a separate compound from the antiscattering component; or   a component of the antiscattering component by virtue of being coordinatively attached,   
       wherein the Z eff  of the secondary electron generator is calculated by excluding the molecule to which it is coordinatively attached. 
     
     
         55 . The method as claimed in  claim 54 , wherein:
 the secondary electron generator is a lewis acid or is derived from a compound that is a lewis acid; and/or   the secondary electron generator comprises a d-block, p-block, or f-block metal species having an atomic number greater than 57.   
     
     
         56 . The method as claimed in  claim 54 , wherein:
 the antiscattering component forms one or more dative bonds with the secondary electron generator such that the secondary electron generator is co-ordinated to the primary metal complex; and/or   one or more ligands of the antiscattering component comprise one or more lone-pair-bearing heteroatoms which co-ordinate with the secondary electron generator.   
     
     
         57 . The method as claimed in  claim 56 , wherein one or more ligands of the antiscattering component which co-ordinate with the secondary electron generator are bifunctional ligands which are a carboxylate defined by the formula R B2 CO 2   − , wherein R B2  is a group comprising a basic or chelating group selected from the group consisting of:
 an optionally substituted heterocyclyl, heteroaryl, heterocyclyl(1-6C)alkyl, or heteroaryl(1-6C)alkyl group;   a (1-12C)alkyl, (1-12C)alkenyl, (1-12C)alkynyl, (3-8C)cycloalkyl, (3-8C)cycloalkenyl, (1-3C)alkyl(3-8C)cycloalkyl, (1-3C)alkyl(3-8C)cycloalkenyl, aryl, (1-3C)alkylaryl, or aryl(1-3C)alkyl group substituted with one or more basic or chelating groups;   a (1-12C)alkyl, (1-12C)alkenyl, (1-12C)alkynyl, (3-8C)cycloalkyl, (3-8C)cycloalkenyl, (1-3C)alkyl(3-8C)cycloalkyl, (1-3C)alkyl(3-8C)cycloalkenyl, aryl, (1-3C)alkylaryl, or aryl(1-3C)alkyl group substituted with an amino, alkylamino, dialkylamino, hydroxyl, (1-6C)alkoxy, carbonyl, immino, thio, or thiocarbonyl group;   a pyridyl, aminophenyl, N-(1-3C)alkylaminophenyl, or N,N-di(1-3C)alkylaminophenyl group; and   isonicotinate.   
     
     
         58 . The method as claimed in  claim 28 , wherein:
 the composition comprises one or more resist components that are distinct and separate from the antiscattering component, said one or more resist components comprising a resist polymer; and/or   the composition comprises one or more resist components that are associated with or otherwise bonded to the antiscattering component or primary metal complex thereof so that together they form an antiscattering-resist hybrid component.   
     
     
         59 . The method as claimed in  claim 28 , wherein:
 the primary metal complex comprises or is otherwise associated with one or more photoresist components in that the one or more photoresist components are photoresist ligands bonded to the primary metal complex via a co-ordination donor atom or group borne by the photoresist ligand(s); and   the photoresist ligand(s) are or otherwise comprises a photosensitive component.   
     
     
         60 . The method as claimed in  claim 59 , wherein the photosensitive component is a photoinitiator, photoacid, or photosensitiser. 
     
     
         61 . The method as claimed in  claim 59 , wherein the photoresist ligand(s) undergo a change upon exposure to relevant radiation and are or otherwise comprise a photosensitive component capable of undergoing photolytic reactions without the assistance of additional photoinitiators and photocatalysts. 
     
     
         62 . The method as claimed in  claim 28 , wherein the antiscattering resist composition comprises a further photosensitive component selected from a photoinitiator, photoacid, or photosensitizer. 
     
     
         63 . The method as claimed in  claim 28 , wherein the antiscattering resist composition is a photoresist composition. 
     
     
         64 . The method as claimed in  claim 28 , wherein the antiscattering resist composition comprises 20-99.5 wt % diluent. 
     
     
         65 . The method as claimed in  claim 28 , wherein the radiation is either electromagnetic radiation, a focused or targeted beam, an electron beam, electron beam radiation, ionizing radiation, or ultraviolet radiation. 
     
     
         66 . The method as claimed in  claim 28 , wherein the radiation is ultraviolet radiation. 
     
     
         67 . The method as claimed in  claim 28 , wherein the radiation is electromagnetic radiation having a wavelength between 10 and 30 nm. 
     
     
         68 . The method as claimed in  claim 28 , wherein the radiation is electromagnetic radiation having a wavelength between 100 nm and 400 nm. 
     
     
         69 . An integrated circuit, integrated circuit package, circuit board, or electronic device or system obtained by the method of  claim 29 . 
     
     
         70 . An integrated circuit, integrated circuit package, circuit board, or electronic device or system obtained by the method of  claim 33 . 
     
     
         71 . A lithographic mask obtained by the method of  claim 30 .