Electron beam resist composition

Patent metadata

Field	Value
Publication number	US-10234764-B2
Application number	US-201515501417-A
Country	US
Kind code	B2
Filing date	Jul 30, 2015
Priority date	Aug 6, 2014
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

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 minimizes 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.

First claim

The invention claimed is:

1. A method of performing electron-beam lithography, the method comprising:
i) providing an (eBeam) resist-coated substrate or applying an (eBeam) resist coating to a substrate;
ii) exposing part(s) of the (eBeam) resist coating to (electron beam) radiation to provide an exposed (eBeam) resist coating;
iii) developing the exposed (eBeam) resist coating to generate an (eBeam) resist pattern layer, the (eBeam) resist pattern layer comprising: developer-insoluble coating portions of the (eBeam) resist coating; and an array of grooves extending through the (eBeam) resist pattern layer;
iv) optionally modifying the substrate, substrate surface, or part(s) thereof, underlying the (eBeam) resist pattern layer;
v) optionally removing the (eBeam) resist pattern layer to provide a modified substrate;
vi) optionally repeating, one or more times, step iv) and/or steps i)-v) (optionally with an alternative resist coating, such as a photoresist, instead of the eBeam resist coating; and optionally using alternative radiation during exposure, such as visible or ultraviolet light, instead of electron beam radiation) upon the modified substrate;

wherein the eBeam resist-coated substrate is a substrate coated with an eBeam resist coating;
wherein the eBeam resist coating comprises an optionally dried and/or cured eBeam resist composition;
wherein the eBeam resist composition comprises an anti-scattering compound; wherein the anti-scattering compound 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.

2. The method of claim 1 , wherein the anti-scattering compound comprises a primary metal complex (PMC), wherein the primary metal complex is a polymetallic cage.

3. The method of claim 2 , wherein the anti-scattering compound comprises a linker component associated with one or more primary metal complexes in a hybrid complex of Formula B:
(PMC) p (LINK) l

wherein:
PMC is a primary metal complex and p is a value between 1 and 30 and is the number of moles of PMC per mole of hybrid complex of Formula B; and
wherein LINK is a linker component and l is a value between 1 and 10 and is the number of moles of LINK per mole of hybrid complex of Formula B;

wherein optionally either or both of the primary metal complex(es) and/or linker component(s) within a hybrid complex are each independently associated with any of the counterions, and/or the counterions may be associated with the hybrid complex as a whole;
wherein the anti-scattering compound optionally comprises one or more counterions associated with the hybrid complex as part of a hybrid complex salt, wherein the hybrid complex salt is defined by Formula C:
(C 1 i1 C 2 i2 . . . C c ic )(PMC) p (LINK) l

wherein C 1 is a first counterion, C 2 is a second counterion, and C c is a cth counterion, wherein i1, i2, and is are the respective number of moles of each of C 1 , C 2 , . . . , and C c per mole of hybrid complex salt of Formula C.

4. The method of claim 2 , wherein the primary metal complex is defined by Formula I or comprises units defined by Formula I:
[M 1 x M 2 y . . . M n zn (monoLIG 1 ) m1 (monoLIG 2 ) m2 . . . (monoLIG 1 ) mq (biLIG 1 ) b1 (biLIG 2 ) b2 . . . (biLIG r ) br (optLIG s ) (optLIG 1 ) o1 (optLIG 2 ) o2 . . . (optLIG s ) os ];

wherein:
M 1 is a first metal species and x is the number of moles of M 1 per mole of primary metal complex, wherein x is a number between 1 and 16;
M 2 is a second metal species and y is the number of moles of M 2 per mole of primary metal complex, wherein y is a number between 0 and 7;
M n is an nth metal species and zn is the number of moles of each M n per mole of primary metal complex, wherein zn is a number between 0 and 6; suitably between 0 and 2; suitably 0;
monoLIG 1 is a first monodentate ligand and m1 is the number of moles of monoLIG 1 per mole of primary metal complex, wherein m1 is a number between 0 and 20;
monoLIG 2 is a second monodentate ligand and m2 is the number of moles of monoLIG 2 per mole of primary metal complex, wherein m2 is a number between 0 and 10;
monoLIG 4 is a qth monodentate ligand and mq is the number of moles of each monoLIG 4 per mole of primary metal complex, wherein mq is a number between 0 and 2;
biLIG r is a first bidentate ligand and b1 is the number of moles of biLIG r per mole of primary metal complex, wherein b1 is a number between 1 and 20;
biLIG 2 is a second bidentate ligand and b2 is the number of moles of biLIG 2 per mole of primary metal complex, wherein b2 is a number between 0 and 16;
biLIG r is a rth bidentate ligand and br is the number of moles of each additional biLIG r per mole of primary metal complex, wherein br is a number between 0 and 2;
optLIG 1 is a first optional extra ligand and o1 is the number of moles of optLIG 1 per mole of primary metal complex, wherein o1 is a number between 0 and 4;
optLIG 2 is a second optional extra/terminal ligand and o2 is the number of moles of optLIG 2 per mole of primary metal complex, wherein o2 is a number between 0 and 3;
optLIG s is a sth optional extra/terminal ligand and os is the number of moles of each additional optional optLIG s per mole of primary metal complex; wherein os is a number between 0 and 2.

5. The method of claim 4 , wherein the sum of x and y is between 4 and 16.

6. The method of claim 4 , wherein M 1 is a trivalent metal species.

7. The method of claim 4 , wherein M 2 is a divalent metal species.

8. The method of claim 6 , wherein M 1 is a trivalent metal species selected from the group including Cr III , Fe III , V III , Ga III , Al III , or In III .

9. The method of claim 7 , wherein M 2 is a divalent metal species selected from the group including Ni II , Co II , Zn II , Cd II , Mn II , Mg II , Ca II , Sr II , Ba II , Cu II , or Fe II .

10. The method of claim 4 , wherein:
biLIG 1 is a carboxylate defined by the formula —O 2 CR B1 (or R B1 CO 2 − ), wherein R B1 is a hydrocarbyl moiety 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;
biLIG 2 is a carboxylate defined by the formula —O 2 CR B2 (or R B2 CO 2 ), wherein R B2 is a group comprising a basic or chelating group, 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, -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;
optLIG 1 is either a solvent molecule or a polydentate ligand having a denticity greater than or equal to 3.

11. The method of claim 10 , wherein the primary metal complex is defined or comprises units defined by either:
by the Formula IIa: [M 1 8-y M 2 y F 8 (O 2 CR B1 ) 16-b2 (O 2 CR B2 ) b2 ]
by the Formula IIb: [CR 7 NiF 8 (O 2 CR B1 ) 16-b2 (O 2 CR B2 ) b2 ];
by the Formula IIc: [Cr 7 NiF 8 (O 2 CR B1 ) 16 ];
by the Formula IId: [Cr 8 F 8 (O 2 CR B1 ) 16-b2 (O 2 CR B2 ) b2 ];
by the Formula IIe: [Cr 8 F 8 (O 2 CR B1 ) 16 ]; or
by the Formula III: [M 1 8-y M 2 y F 3 (O 2 CR B1 ) 15 (Gluc-NH—R O1 )], wherein Gluc-NH—R O1 is N-(1-8C)alkyl-D-glucamine.

12. The method of claim 3 , wherein the or each linker component (LINK) is independently selected from:
i) a single atom, molecule, ion, or complex containing a single co-ordinating moiety capable of accepting or donating two or more lone pair

Assignees

• Univ Manchester

Inventors

• Lewis Scott
• Winpenny Richard
• Yeates Stephen

Classifications

• G03F7/027

  Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds (G03F7/075 takes precedence) · CPC title

• G03F7/039

  Macromolecular compounds which are photodegradable, e.g. positive electron resists (G03F7/075 takes precedence; macromolecular quinonediazides G03F7/023) · CPC title

• G03F7/0047 Primary

  characterised by additives for obtaining a metallic or ceramic pattern, e.g. by firing · CPC title

• G03F7/2059 Primary

  using a scanning corpuscular radiation beam, e.g. an electron beam · CPC title

• H01J37/3175

  Projection methods, i.e. transfer substantially complete pattern to substrate · CPC title