Electron beam resist composition

Abstract

The present invention relates to an electron beam (eBeam) resist composition, particularly an (eBeam) resist composition for use in the fabrication of integrated circuits. Such resist compositions include an anti-scattering compound which minimises scattering and secondary electron generation, thus affording extremely high resolution lithography. Such high resolution lithography may be used directly upon silicon-based substrates to produce integrated circuits, or may alternatively be used to produce a lithographic mask (e.g. photomask) to facilitate high-resolution lithography.

The invention claimed is: 
     
       1. An antiscattering anti-scattering resist composition for fabricating an integrated circuit die or an integrated circuit wafer, the composition comprising an anti-scattering compound, wherein the antiscattering compound is a polymetallic metal-organic complex comprising a primary metal complex (PMC), wherein the primary metal complex comprises one or more metal species, and wherein the one or more metal species exclude boron and/or silicon species, wherein the primary metal complex is a polymetallic cage or polymetallic ring. 
     
     
       2. The antiscattering An anti-scattering resist composition for fabricating an integrated circuit die or an integrated circuit wafer, the composition comprising an anti-scattering compound, wherein the anti-scattering compound is a polymetallic metal-organic complex comprising a primary metal complex (PMC), wherein the primary metal complex comprises one or more metal species, and wherein the one or more metal species exclude boron and/or silicon species; wherein the anti-scattering resist composition of  claim 1 , further comprising comprises a scattering compound comprising one or more electron-containing π- and/or p-orbitals, suitably characterized by alkene and/or alkyne moieties, optionally wherein the scattering compound comprises one or more atoms capable of datively co-ordinating with the anti-scattering compound/complex. 
     
     
       3. The antiscattering An anti-scattering resist composition for fabricating an integrated circuit die or an integrated circuit wafer, the composition comprising an anti-scattering compound, wherein the anti-scattering compound is a polymetallic metal-organic complex comprising a primary metal complex (PMC), wherein the primary metal complex comprises one or more metal species, and wherein the one or more metal species exclude boron and/or silicon species; wherein the anti-scattering resist composition of  claim 1 , further comprising comprises a secondary electron generator, which secondary electron generator is or comprises a compound comprising a d-block, p-block, or f-block metal species having an atomic number greater than or equal to 49; wherein:
 optionally the secondary electron generator is or comprises a compound having an effective atomic number (Z eff ) greater than or equal to 15, wherein:
   Z eff =Σα i Z i  
 
 
 where Z i , is the atomic number of the ith element in the compound, and α i  is the fraction of the sum total of the atomic numbers of all atoms in the compound (i.e. the total number of protons in the compound) constituted by said ith element; 
 optionally the antiscattering anti-scattering compound/complex forms one or more dative bonds with the secondary electron generator. 
 
     
     
       4. The antiscattering anti-scattering resist composition of  claim 1 , wherein the antiscattering anti-scattering compound is heterometallic. 
     
     
       5. The antiscattering anti-scattering resist composition of  claim 4 , wherein at least one metal species of the antiscattering anti-scattering compound is a transition metal species. 
     
     
       6. The antiscattering anti-scattering resist composition of  claim 1 , wherein the antiscattering anti-scattering compound comprises:
 at least one trivalent metal species selected from the group consisting of Cr III , Fe III , V III , Ga III , Al III , and In III , most suitably Cr III ; and 
 at least one divalent metal species 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 , most suitably Ni II . 
 
     
     
       7. The antiscattering anti-scattering resist composition of  claim 1 , wherein the anti-scattering compound has a solubility of at least 10 mg/g in hexane. 
     
     
       8. The antiscattering anti-scattering resist composition of  claim 1 , wherein the antiscattering anti-scattering compound comprises a ligand which is a linker component that is capable of acting as a lewis acid and/or a lewis base. 
     
     
       9. The antiscattering anti-scattering resist composition of  claim 1 , wherein the antiscattering anti-scattering compound itself serves as a resist component, whose developer-solubility properties change following exposure to radiation. 
     
     
       10. The antiscattering anti-scattering resist composition of  claim 1 , wherein the composition comprises 20-99 wt % solvent. 
     
     
       11. The antiscattering anti-scattering resist composition of  claim 1  wherein the composition is a solution. 
     
     
       12. The antiscattering anti-scattering resist composition of  claim 11 , wherein the composition is free of any dispersed or suspended particulate matter. 
     
     
       13. The antiscattering anti-scattering resist composition of  claim 1 , wherein the composition is spin-coatable. 
     
     
       14. The antiscattering anti-scattering resist composition of  claim 1 , wherein the anti-scattering compound controls the flow and/or scattering of electrons when exposed to radiation. 
     
     
       15. The antiscattering anti-scattering resist composition of  claim 1 , wherein the anti-scattering compound has a density less than or equal to 1.5 g/cm 3 . 
     
     
       16. A method of fabricating an integrated circuit die or an integrated circuit wafer comprising a plurality of integrated circuit dice, the or each die comprising a plurality of electronic components, wherein the method comprises:
 i) providing an antiscattering anti-scattering resist-coated substrate or applying an antiscattering anti-scattering resist coating to a substrate; and 
 ii) exposing parts of the resist coating to radiation to provide an exposed resist coating;
 OR 
 
 i) providing:
 a. a resist-coated substrate or applying a resist coating to a substrate; and 
 b. a lithographic mask comprising a mask pattern characterised by regions of surface/substrate transparency juxtaposed with regions of surface/substrate opacity, wherein the lithographic mask is obtained by performing lithography upon an antiscattering anti-scattering resist-coated mask substrate; and 
 
 ii) exposing parts of the resist coating, through the lithographic mask to radiation to provide an exposed resist coating;
 AND THEN 
 
 iii) developing the exposed resist coating to generate a resist pattern layer, the resist pattern layer comprising: developer-insoluble coating portions of the resist coating (i.e. ridges); and an array of grooves extending through the resist pattern layer; 
 iv) modifying the substrate, substrate surface, or parts thereof, underlying the resist pattern layer; 
 v) removing the resist pattern layer to provide a modified substrate; 
 vi) optionally repeating, one or more times, upon the modified substrate step iv) and/or steps i)-v) with either an antiscattering anti-scattering resist coating or an alternative resist coating, optionally using alternative radiation; 
 vii) conductively interconnecting the electronic components of the or each die with conductors if not already performed during one or more substrate/substrate-surface modifying steps to provide an integrated circuit with external contact terminals; 
 viii) optionally performing one or more further finishing steps; 
 ix) optionally separating an integrated circuit die from a wafer comprising a plurality of integrated circuit dice; 
 
       wherein:
 the antiscattering anti-scattering resist-coated substrate is a substrate coated with an antiscattering anti-scattering resist coating; 
 the antiscattering anti-scattering resist coating comprises an optionally dried and/or cured antiscattering anti-scattering resist composition, wherein the anti-scattering resist composition is optionally dried and/or cured; and  
 the antiscattering anti-scattering resist composition is as claimed in  claim 1  comprises an anti-scattering compound, wherein the anti-scattering compound is a polymetallic metal-organic complex comprising a primary metal complex (PMC), wherein the primary metal complex comprises one or more metal species, and wherein the one or more metal species exclude boron and/or silicon species. 
 
     
     
       17. A method of manufacturing an integrated circuit package, the integrated circuit package comprising a plurality of pins and an integrated circuit die with external contact terminals conductively connected to the corresponding plurality of pins, wherein the method comprises:
 i) providing an integrated circuit die by or obtained by a method of fabricating an integrated circuit die as claimed in  claim 16 ; 
 ii) attaching the integrated circuit die to a package substrate, wherein the package substrate comprises electrical contacts, each of the electrical contacts being optionally connected or connectable to a corresponding pin; 
 iii) conductively connecting each of the external contact terminals of the integrated circuit die to corresponding electrical contacts of the package substrate; 
 iv) optionally and if necessary connecting the electrical contacts of the package substrate to corresponding pins; 
 v) encapsulating the integrated circuit die. 
 
     
     
       18. A method of manufacturing a circuit board comprising an integrated circuit package comprising a plurality of pins, wherein the method comprises:
 i) providing an integrated circuit package by or obtained by a method of manufacturing an integrated circuit package as claimed in  claim 17 ; 
 ii) conductively connecting the integrated circuit package to a circuit board. 
 
     
     
       19. A method of manufacturing an electronic device or system, the electronic device or system comprising or being connectable to a power source and comprising a circuit board conductively connected to or connectable to a power source, wherein the method comprises:
 i) providing a circuit board by or obtained by the method of manufacturing a circuit board as claimed in  claim 18 ; 
 ii) incorporating the circuit board within the electronic device or system. 
 
     
     
       20. The method of fabricating an integrated circuit die or an integrated circuit wafer of  claim 16 , wherein the radiation used during exposure of the antiscattering anti-scattering resist coating is ionizing radiation. 
     
     
       21. The method of  claim 16 , wherein the average thickness of the antiscattering anti-scattering resist coating is 10-200 nm. 
     
     
       22. The anti-scattering composition of  claim 1 , wherein the anti-scattering compound is a polymetallic metal-organic complex comprising a primary metal complex (PMC) which is a metal complex comprising one or more metal species, other than boron and silicon species, and one or more ligands co-ordinated to one, more, or all of the metal species; wherein one or more of the ligands are bridging ligands that bind together metal species within the primary metal complex.  
     
     
       23. The method of fabricating an integrated circuit die or an integrated circuit wafer of  claim 16 , wherein the primary metal complex is a polymetallic cage or polymetallic ring.  
     
     
       24. An anti-scattering resist composition for fabricating an integrated circuit die or an integrated circuit wafer, the composition comprising an anti-scattering compound, wherein the anti-scattering compound is a polymetallic metal-organic complex comprising a primary metal complex (PMC), wherein the primary metal complex comprises one or more metal species, and wherein the one or more metal species exclude boron and/or silicon species; wherein the anti-scattering compound has a density less than or equal to 1.5 g/cm 3  and a molecular weight greater than or equal to 2000 g/mol.  
     
     
       25. The anti-scattering composition of  claim 1 , wherein at least one of the metal species of the primary metal complex is magnetic or paramagnetic.  
     
     
       26. The anti-scattering composition of  claim 1 , wherein the primary metal complex comprises two or more different metal ions that are either derived from the same metal element and have a different valency, or derived from a different metal element and have the same or a different valency.  
     
     
       27. The anti-scattering composition of  claim 1 , wherein the primary metal complex comprises two or more different metal species, at least M 1  and M 2 , derived respectively from two or more different metal elements; and the primary metal complex comprises one or more ligands coordinated to one or both M 1  and M 2 , wherein one or more are bridging ligands providing a bridge between two or more metal species of the primary metal complex.  
     
     
       28. The anti-scattering composition of  claim 27 , wherein the molar ratio of M 1  to M 2  is between 10:1 and 2:1.  
     
     
       29. The anti-scattering composition of  claim 28 , wherein M 1  is Cr III  and M 2  is Ni II .  
     
     
       30. An anti-scattering resist composition for fabricating an integrated circuit die or an integrated circuit wafer, the composition comprising an anti-scattering compound, wherein the anti-scattering compound is a polymetallic metal-organic complex comprising a primary metal complex (PMC), wherein the primary metal complex comprises one or more metal species, and wherein the one or more metal species exclude boron and/or silicon species; wherein the primary metal complex comprises a mixture of ligands.  
     
     
       31. The anti-scattering composition of  claim 30 , wherein the mixture of ligands comprises a bidentate ligand a monodentate.  
     
     
       32. The anti-scattering composition of  claim 31 , wherein the monodentate ligand is fluoride, and the bidentate ligand is a carboxylate.  
     
     
       33. The anti-scattering composition of  claim 1 , wherein the primary metal complex comprises one or more bidentate ligands that are a carboxylate defined by the formula R B1 CO 2   − , wherein R B1  is a group devoid of basic or chelating groups, and is selected from (1-12C)alkyl, (2-12C)alkenyl, (2-12C)alkynyl, (3-8C)cycloalkyl, (3-8C)cycloalkenyl, (1-3C)alkyl (3-8C)cycloalkyl, (1-3C)alkyl(3-8C)cycloalkenyl, aryl, (1-3C)alkylaryl, and aryl(1-3C)alkyl.  
     
     
       34. An anti-scattering resist composition for fabricating an integrated circuit die or an integrated circuit wafer, the composition comprising an anti-scattering compound, wherein the anti-scattering compound is a polymetallic metal-organic complex comprising a primary metal complex (PMC), wherein the primary metal complex comprises one or more metal species, and wherein the one or more metal species exclude boron and/or silicon species; wherein the primary metal complex comprises a bifunctional ligand comprising co-ordinating atom(s) capable of forming an internal dative bond(s) with metal species within the primary metal complex, and one or more additional co-ordinating atoms capable of forming external dative bonds.  
     
     
       35. The anti-scattering composition of in  claim 34 , wherein the bifunctional ligand comprises a carboxylate group and an additional nitrogen-containing moiety.  
     
     
       36. The anti-scattering composition of in  claim 35 , wherein the bifunctional ligand is 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, (1-3 C)alkyl(3-8C)cycloalkyl, (1-3 C)alkyl(3-8C)cycloalkenyl, aryl, (1-3 C)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, (1-3 C)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.    
     
     
       37. The anti-scattering composition of  claim 1 , wherein the anti-scattering compound comprises one or more counterions associated with the primary metal complex.  
     
     
       38. The anti-scattering composition of  claim 37 , wherein the one or more counterions comprise one or more cations selected from the group consisting of an ammonium cation, a primary ammonium cation, a secondary ammonium cation, a tertiary ammonium cation, a quaternary ammonium cation, and an imidazolium cation.  
     
     
       39. The anti-scattering composition of  claim 3 , wherein the secondary electron generator is a metal (I), metal (II), metal (III), or metal (IV) halide.  
     
     
       40. The anti-scattering composition of  claim 3 , wherein one or more ligands of the anti-scattering compound comprise one or more lone-pair-bearing heteroatoms which co-ordinate with the secondary electron generator.  
     
     
       41. The anti-scattering composition of  claim 3 , wherein the molar ratio of the secondary electron generator to primary metal complex(es) is between 0.5:1 and 8:1.  
     
     
       42. An anti-scattering resist composition for fabricating an integrated circuit die or an integrated circuit wafer, the composition comprising an anti-scattering compound, wherein the anti-scattering compound is a polymetallic metal-organic complex comprising a primary metal complex (PMC), wherein the primary metal complex comprises one or more metal species, and wherein the one or more metal species exclude boron and/or silicon species; wherein the composition further comprises a resist polymer.  
     
     
       43. A method of performing lithography, the method comprising:
 i) providing a resist-coated substrate or applying a resist coating to a substrate; exposing part(s) of the resist coating to radiation or a focused/targeted ion beam to provide an exposed resist coating;   ii) developing the exposed resist coating to generate a resist pattern layer, the resist pattern layer comprising: developer-insoluble coating portions of the resist coating; and an array of grooves extending through the resist pattern layer;   iii) optionally modifying the substrate, substrate surface, or part(s) thereof, underlying the resist pattern layer;   iv) optionally removing the resist pattern layer to provide a modified substrate;   v) optionally repeating, one or more times, step iv) and/or steps i)-v) (optionally with an alternative resist coating; and optionally using alternative radiation during exposure) upon the modified substrate;   wherein the resist-coated substrate is a substrate coated with a resist coating;   wherein the resist coating comprises a resist composition, wherein the resist composition is optionally dried and/or cured;   wherein the resist composition is the anti-scattering resist composition as claimed in claim 1.    
     
     
       44. The method of performing lithography as claimed in  claim 43 , wherein the substrate is a lithographic mask substrate and the method provides a lithographic mask.  
     
     
       45. A method of performing lithography, the method comprising:
 i) providing a resist-coated substrate or applying a resist coating to a substrate; exposing part(s) of the resist coating to radiation or a focused/targeted ion beam to provide an exposed resist coating;   ii) developing the exposed resist coating to generate a resist pattern layer, the resist pattern layer comprising: developer-insoluble coating portions of the resist coating; and an array of grooves extending through the resist pattern layer;   iii) optionally modifying the substrate, substrate surface, or part(s) thereof, underlying the resist pattern layer;   iv) optionally removing the resist pattern layer to provide a modified substrate; v) optionally repeating, one or more times, step iv) and/or steps i)-v) (optionally with an alternative resist coating; and optionally using alternative radiation during exposure) upon the modified substrate;   wherein the resist-coated substrate is a substrate coated with a resist coating;   wherein the resist coating comprises a resist composition, wherein the resist composition is optionally dried and/or cured;   wherein the resist composition is the anti-scattering resist composition as claimed in claim 2.    
     
     
       46. The method of performing lithography as claimed in  claim 45 , wherein the substrate is a lithographic mask substrate and the method provides a lithographic mask.  
     
     
       47. A method of performing lithography, the method comprising:
 i) providing a resist-coated substrate or applying a resist coating to a substrate; exposing part(s) of the resist coating to radiation or a focused/targeted ion beam to provide an exposed resist coating;   ii) developing the exposed resist coating to generate a resist pattern layer, the resist pattern layer comprising: developer-insoluble coating portions of the resist coating; and an array of grooves extending through the resist pattern layer;   iii) optionally modifying the substrate, substrate surface, or part(s) thereof, underlying the resist pattern layer;   iv) optionally removing the resist pattern layer to provide a modified substrate;   v) optionally repeating, one or more times, step iv) and/or steps i)-v) (optionally with an alternative resist coating; and optionally using alternative radiation during exposure) upon the modified substrate;   wherein the resist-coated substrate is a substrate coated with a resist coating;   wherein the resist coating comprises a resist composition, wherein the resist composition is optionally dried and/or cured;   wherein the resist composition is the anti-scattering resist composition as claimed in claim 3.    
     
     
       48. The method of performing lithography as claimed in  claim 47 , wherein the substrate is a lithographic mask substrate and the method provides a lithographic mask.  
     
     
       49. A method of performing lithography, the method comprising:
 i) providing a resist-coated substrate or applying a resist coating to a substrate; exposing part(s) of the resist coating to radiation or a focused/targeted ion beam to provide an exposed resist coating;   ii) developing the exposed resist coating to generate a resist pattern layer, the resist pattern layer comprising: developer-insoluble coating portions of the resist coating; and an array of grooves extending through the resist pattern layer;   iii) optionally modifying the substrate, substrate surface, or part(s) thereof, underlying the resist pattern layer;   iv) optionally removing the resist pattern layer to provide a modified substrate;   v) optionally repeating, one or more times, step iv) and/or steps i)-v) (optionally with an alternative resist coating; and optionally using alternative radiation during exposure) upon the modified substrate;   wherein the resist-coated substrate is a substrate coated with a resist coating;   wherein the resist coating comprises a resist composition, wherein the resist composition is optionally dried and/or cured;   wherein the resist composition is the anti-scattering resist composition as claimed in claim 24.    
     
     
       50. The method of performing lithography as claimed in  claim 49 , wherein the substrate is a lithographic mask substrate and the method provides a lithographic mask.  
     
     
       51. A method of performing lithography, the method comprising:
 i) providing a resist-coated substrate or applying a resist coating to a substrate; exposing part(s) of the resist coating to radiation or a focused/targeted ion beam to provide an exposed resist coating;   ii) developing the exposed resist coating to generate a resist pattern layer, the resist pattern layer comprising: developer-insoluble coating portions of the resist coating; and an array of grooves extending through the resist pattern layer;   iii) optionally modifying the substrate, substrate surface, or part(s) thereof, underlying the resist pattern layer;   iv) optionally removing the resist pattern layer to provide a modified substrate;   v) optionally repeating, one or more times, step iv) and/or steps i)-v) (optionally with an alternative resist coating; and optionally using alternative radiation during exposure) upon the modified substrate;   wherein the resist-coated substrate is a substrate coated with a resist coating;   wherein the resist coating comprises a resist composition, wherein the resist composition is optionally dried and/or cured;   wherein the resist composition is the anti-scattering resist composition as claimed in claim 30.    
     
     
       52. The method of performing lithography as claimed in  claim 51 , wherein the substrate is a lithographic mask substrate and the method provides a lithographic mask.  
     
     
       53. A method of performing lithography, the method comprising:
 i) providing a resist-coated substrate or applying a resist coating to a substrate; exposing part(s) of the resist coating to radiation or a focused/targeted ion beam to provide an exposed resist coating;   ii) developing the exposed resist coating to generate a resist pattern layer, the resist pattern layer comprising: developer-insoluble coating portions of the resist coating; and an array of grooves extending through the resist pattern layer;   iii) optionally modifying the substrate, substrate surface, or part(s) thereof, underlying the resist pattern layer;   iv) optionally removing the resist pattern layer to provide a modified substrate; v) optionally repeating, one or more times, step iv) and/or steps i)-v) (optionally with an alternative resist coating; and optionally using alternative radiation during exposure) upon the modified substrate;   wherein the resist-coated substrate is a substrate coated with a resist coating;   wherein the resist coating comprises a resist composition, wherein the resist composition is optionally dried and/or cured;   wherein the resist composition is the anti-scattering resist composition as claimed in claim 34.    
     
     
       54. The method of performing lithography as claimed in  claim 53 , wherein the substrate is a lithographic mask substrate and the method provides a lithographic mask.  
     
     
       55. A method of performing lithography, the method comprising:
 i) providing a resist-coated substrate or applying a resist coating to a substrate; exposing part(s) of the resist coating to radiation or a focused/targeted ion beam to provide an exposed resist coating;   ii) developing the exposed resist coating to generate a resist pattern layer, the resist pattern layer comprising: developer-insoluble coating portions of the resist coating; and an array of grooves extending through the resist pattern layer;   iii) optionally modifying the substrate, substrate surface, or part(s) thereof, underlying the resist pattern layer;   iv) optionally removing the resist pattern layer to provide a modified substrate;   v) optionally repeating, one or more times, step iv) and/or steps i)-v) (optionally with an alternative resist coating; and optionally using alternative radiation during exposure) upon the modified substrate;   wherein the resist-coated substrate is a substrate coated with a resist coating;   wherein the resist coating comprises a resist composition, wherein the resist composition is optionally dried and/or cured;   wherein the resist composition is the anti-scattering resist composition as claimed in claim 42.    
     
     
       56. The method of performing lithography as claimed in  claim 55 , wherein the substrate is a lithographic mask substrate and the method provides a lithographic mask.