CHEMOEPITAXY ETCH TRIM USING A SELF ALIGNED HARD MASK FOR METAL LINE TO VIA

• US 20160365280A1
• Filed: 06/12/2015
• Published: 12/15/2016
• Est. Priority Date: 06/12/2015
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Brink, Markus, Guillorn, Michael A., Lin, Chung-Hsun, Tsai, HsinYu
• Granted Patent: US 9,646,883 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G03F 7/0002 Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping
• CPC Class Codes: H01L 21/02118 carbon based polymeric organic or inorganic material, e.g. polyimides, poly cyclobutene or PVC polymers per se C08G, photoresist per se G03F
• CPC Class Codes: H01L 21/31133 by chemical means
• CPC Class Codes: H01L 21/31144 using masks
• CPC Class Codes: H01L 21/76802 by forming openings in dielectrics
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/76816 Aspects relating to the layout of the pattern or to the size of vias or trenches layout of the interconnections per se H01L23/528; CAD of ICs G06F30/00
• CPC Class Codes: H01L 21/76823 transforming an insulating layer into a conductive layer
• CPC Class Codes: H01L 21/76838 characterised by the formation and the after-treatment of the conductors etching for patterning the conductors H01L21/3213
• CPC Class Codes: H01L 21/76849 the layer being positioned on top of the main fill metal
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76879 by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288
• CPC Class Codes: H01L 21/76897 Formation of self-aligned vias or contact plugs, i.e. involving a lithographically uncritical step self-aligned silicidation on field effect transistors H01L29/665
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/528 Geometry or layout of the interconnection structure H01L27/0207 takes precedence; algorithms G06F30/00
• CPC Class Codes: H01L 23/5329 Insulating materials

Abstract

A method of forming metal lines that are aligned to underlying metal features that includes forming a neutral layer atop a hardmask layer that is overlying a dielectric layer. The neutral layer is composed of a neutral charged di-block polymer. Patterning the neutral layer, the hardmask layer and the dielectric layer to provide openings that are filled with a metal material to provide metal features. A self-assembled di-block copolymer material is deposited on a patterned surface of the neutral layer and the metal features. The self-assembled di-block copolymer material includes a first block composition with a first affinity for alignment to the metal features. The first block composition of the self-assembled di-block copolymer is converted to a metal that is self-aligned to the metal features.

Claims

1. A method of forming electrically conductive structures that are aligned to underlying metal features comprising:

forming a neutral layer overlying a dielectric layer;

patterning the neutral layer and the dielectric layer to provide openings that are filled with a metal material to provide first metal features;

depositing a self-assembled di-block copolymer material on a patterned surface of the neutral layer and the first metal features, the self-assembled di-block copolymer material includes a first block composition with a first affinity for alignment to the first metal features;

converting the first block composition of the self-assembled di-block copolymer to second metal features that are self-aligned to the first metal features.

2. The method of claim 1, wherein the neutral layer comprises a neutral charged di-block polymer.

3. The method of claim 2, wherein the neutral layer comprises a coating of a crosslinked epoxy-containing polymer prepared from monomers comprising glycidyl (meth)acrylate, 2, 3-epoxycyclohexyl (meth)acrylate, (2,3-epoxycyclohexyl)methyl (meth)acrylate, 5,6-epoxynorbornene (meth)acrylate, epoxydicyclopentadienyl (meth)acrylate, or combinations thereof.

4. The method of claim 1 further comprising a hard mask layer between the neutral layer and the dielectric layer.

5. The method of claim 1, wherein the self-assembled di-block copolymer material assembles into a first and second set of lamellae, the first set of lamellae comprise the first block composition and the second set of lamellae comprise a second block composition of the self-assembled di-block copolymer material.

6. The method of claim 1, wherein the second set of lamellae are present on a surface of the neutral layer.

7. The method of claim 1, wherein the first metal features comprise at least one via, and said second metal feature comprises at least one metal line.

8. The method of claim 1, wherein the self-assembled di-block copolymer material comprises polystyrene-block-polymethylmethacrylate (PS-b-PMMA), polystyrene-block-polyisoprene (PS-b-PI), polystyrene-block-polybutadiene (PS-b-PBD), polystyrene-block-polyvinylpyridine (PS-b-PVP), polystyrene-block-polyethyleneoxide (PS-b-PEO), polystyrene-block-polyethylene (PS-b-PE), polystyrene-b-polyorganosilicate (PS-b-POS), polystyrene-block-polyferrocenyldimethylsilane (PS-b-PFS), polyethyleneoxide-block-polyisoprene (PEO-b-PI), polyethyleneoxide-block-polybutadiene (PEO-b-PBD), polyethyleneoxide-block-polymethylmethacrylate (PEO-b-PMMA), polyethyleneoxide-block-polyethylethylene (PEO-b-PEE), polybutadiene-block-polyvinylpyridine (PBD-b-PVP), polyisoprene-block-polymethylmethacrylate (PI-b-PMMA) or combinations thereof.

9. The method of claim 1, wherein said converting the first block composition of the self-assembled di-block copolymer to a second metal feature that is self-aligned to the first metal features comprises:

sequential infiltration synthesis (SIS) of a metal containing material into the first block composition of the self-assembled di-block copolymer;

removal of the polymer scaffold of the first block composition of the self-assembled di-block copolymer; and

reduction of the metal containing material into a metal that provides said second metal features.

10. The method of claim 9, wherein said reduction of the metal containing material comprises reduction of a metal oxide with a hydrogen gas.

18. The electrical communication structure of claim 1, wherein the block copolymer composition comprises polyolefins, polydienes, polyethers, poly(alkylene oxides), poly(ethylene oxide), poly(propylene oxide), poly(butylene oxide), poly((meth)acrylates), polystyrenes, polyesters, polyorganosiloxanes, polyorganogermanes or combinations thereof.

19. The electrical communication structure of claim 1, wherein the neutral layer comprises a crosslinked epoxy-containing polymer prepared from monomers comprising glycidyl (meth)acrylate, 2, 3-epoxycyclohexyl (meth)acrylate, (2,3-epoxycyclohexyl)methyl (meth)acrylate, 5,6-epoxynorbornene (meth)acrylate, epoxydicyclopentadienyl (meth)acrylate or combinations thereof.

20. The electrical communication structure of claim 1, wherein a liner material is not present between the metal lines and the layer including the block copolymer composition.

11. A method of forming electrically conductive structures that are aligned to underlying metal features comprising:

forming a neutral layer overlying a dielectric layer;

forming first metal features through the neutral layer and the dielectric layer;

depositing a self-assembled di-block copolymer material atop the neutral layer and the first metal features, wherein the self-assembled di-block copolymer material includes a first block composition with a first affinity for alignment to the first metal features;

removing the first block composition of the self-assembled di-block copolymer material that is aligned with the first metal features selectively to a remainder of the self-assembled di-block that is not aligned with the first metal features; and

forming a metal in opening provided by said removing the first block composition to provide second metal features that are self-aligned with the first metal features.

12. The method of claim 11, wherein the neutral layer is comprised of a neutral charged di-block polymer.

13. The method of claim 11 further comprising a hard mask layer between the neutral layer and the dielectric layer.

14. The method of claim 11, wherein the self-assembled di-block copolymer material assembles into a first and second set of lamellae, the first set of lamellae comprise the first block composition and the second set of lamellae comprise a second block composition of the self-assembled di-block copolymer material.

15. The method of claim 11, wherein said removing the first block composition comprises an etch process.

16. The method of claim 11, wherein said forming the metal in the opening provided by said removing the first block composition to provide the second metal features comprises chemical vapor deposition, physical vapor deposition or a combination thereof.

17. An electrical communication structure comprising:

metal vias in a dielectric layer;

a neutral charged di-block polymer layer on at least a portion of dielectric layer; and

metal lines present in a layer including a block copolymer composition from a self-assembled di-block copolymer layer that is present atop the neutral charged di-block polymer layer, wherein the metal lines are self-aligned to the metal vias.