Dual damascene fabrication with low k materials

• US 20080020570A1
• Filed: 07/18/2006
• Published: 01/24/2008
• Est. Priority Date: 07/18/2006
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Naik, Mehul
• Granted Patent: US 7,618,889 B2
• Time in Patent Office: Days
• US Class Current: 438/675
• 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 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02167 the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: H01L 21/31144 using masks
• CPC Class Codes: H01L 21/31633 Deposition of carbon doped silicon oxide, e.g. SiOC
• CPC Class Codes: H01L 21/76808 involving intermediate temporary filling with material
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence
• CPC Class Codes: H01L 21/76835 Combinations of two or more different dielectric layers having a low dielectric constant H01L21/76832 takes precedence

Abstract

The invention provides methods and apparatuses for fabricating a dual damascene structure on a substrate. First, trench lithography and trench patterning are performed on the surface of a substrate to etch a low-k dielectric material layer to a desired etch depth to form a trench prior to forming of a via. The trenches can be filled with an organic fill material and a dielectric hard mask layer can be deposited. Then, via lithography and via resist pattering are performed. Thereafter, the dielectric hard mask and the organic fill material are sequentially etched to form vias on the surface of the substrate, where the trenches are protected by the organic fill material from being etched. A bottom etch stop layer on the bottom of the vias is then etched and the organic fill material is striped. As a result, the invention provides good patterned profiles of the via and trench openings of a dual damascene structure.

Claims

1. A method of forming a dual damascene structure on the surface of a substrate, comprising:

depositing a dielectric film stack comprising a bottom barrier layer and a bulk dielectric insulating layer on the surface of the substrate;

applying a first resist material layer over the dielectric film stack;

performing trench lithography on the first resist material layer to form a trench pattern thereon;

etching the dielectric film stack until an desired etching depth to define one or more trenches therein according to the trench pattern on the first resist material layer;

removing the first resist material layer from the surface of the substrate;

filling the one or more trenches with an organic material;

depositing a mask layer over the organic material filling the one or more trenches;

applying a second resist material layer over the mask layer;

performing via lithography on the second resist material layer to form a via pattern thereon;

etching the mask layer to define one or more vias within the organic material filled trenches according to the via pattern on the second resist material layer;

etching the organic material to form the one or more vias therein according to the via pattern;

etching the bulk dielectric insulating layer to form the one or more vias therein according to the via pattern;

etching the bottom barrier layer to form the one or more vias therein according to the via pattern;

removing the organic material from the organic material filled trenches and the one or more vias; and

forming the one or more trenches and one or more vias therein the dielectric film stack on the surface of the substrate.

2. The method of claim 1, wherein the bulk dielectric insulating layer comprises a low K dielectric material selected from the group consisting of organosilicate materials, porous oxide materials, silsesquioxane materials, paralyne, polymer materials, benzocyclobutene, polytetrafluoroethylene, parylene, polyether, polyimide, polyamide materials, carbon-doped dielectrics materials, carbon-doped organo-silicate glass (OSG) materials, carbon-doped silicon dioxides, spin-on glass materials, un-doped silicon glass (USG) materials, fluorine-doped silicon glass (FSG) materials, carbon containing silicon materials, silicon oxycarbides (SiOC), and combinations thereof.

3. The method of claim 1, wherein the bottom barrier layer comprises a low K dielectric material selected from the group consisting of carbon containing silicon materials, silicon oxycarbides (SiOC), silicon carbides, silicon nitrides (SiN), carbon containing silicon nitride materials (SiCN), and combinations thereof.

4. The method of claim 1, wherein the dielectric film stack further comprises one or more top dielectric material layer.

5. The method of claim 4, wherein the one or more top dielectric material layers comprises a hard mask material selected from the group consisting of silicon oxynitrides (SiON), carbon containing silicon materials, silicon oxycarbides (SiOC), silicon carbides, silicon nitrides (SiN), carbon containing silicon nitride materials (SiCN), silicon oxide (SiO₂), tetra-ethyl-ortho-silicate (TEOS) based oxide, and combinations thereof.

6. The method of claim 1, wherein the dielectric film stack further comprises a hard mask material layer having a material selected from the group consisting of tantalum, titanium, tungsten, tantalum nitride, titanium nitride, tungsten nitride, amorphous silicon, and combinations thereof, deposited over the dielectric film stack

7. The method of claim 1, wherein the bulk dielectric insulating layer comprises a first dielectric material layer, a second dielectric material layer, and an etch stop layer between the first and the second dielectric material layers.

8. The method of claim 1, wherein the substrate is annealed after the dielectric film stack is etched to the desired etching depth.

9. The method of claim 1, further comprising cleaning of the surface of the substrate.

10. The method of claim 1, further comprising depositing an additional organic fill material layer between the mask layer and the second resist material layer.

11. The method of claim 1, further comprising annealing the surface of the substrate after the one or more trenches and one or more vias are formed.

12. A method of forming a dual damascene structure on the surface of a substrate having a bottom barrier layer, a bulk dielectric insulating layer, and a first resist material layer deposited thereon, comprising:

performing trench lithography on the first resist material layer to form a trench pattern thereon;

etching the bulk dielectric insulating layer until an desired etching depth to define one or more trenches therein according to the trench pattern on the first resist material layer;

filling the one or more trenches with an organic material;

depositing a mask layer over the organic material and a second resist material layer over the mask layer;

performing via lithography on the second resist material layer to form a via pattern thereon;

etching the mask layer to define one or more vias within the organic material filled trenches according to the via pattern on the second resist material layer;

etching the organic material and the bulk dielectric insulating layer to form the one or more vias therein according to the via pattern;

etching the bottom barrier layer to form the one or more vias therein according to the via pattern;

removing the organic material from the organic material filled trenches and the one or more vias; and

forming the one or more trenches and one or more vias therein the dielectric film stack on the surface of the substrate.

13. The method of claim 12, wherein the bulk dielectric insulating layer comprises a low K dielectric material selected from the group consisting of organosilicate materials, porous oxide materials, silsesquioxane materials, paralyne, polymer materials, benzocyclobutene, polytetrafluoroethylene, parylene, polyether, polyimide, polyamide materials, carbon-doped dielectrics materials, carbon-doped organo-silicate glass (OSG) materials, carbon-doped silicon dioxides, spin-on glass materials, un-doped silicon glass (USG) materials, fluorine-doped silicon glass (FSG) materials, carbon containing silicon materials, silicon oxycarbides (SiOC), and combinations thereof.

14. The method of claim 12, further comprising one or more top dielectric material layers deposited between the bulk dielectric insulating layer and the first resist material layer, wherein the one or more top dielectric material layers comprises a material selected from the group consisting of silicon oxynitrides (SiON), carbon containing silicon materials, silicon oxycarbides (SiOC), silicon carbides, silicon nitrides (SiN), carbon containing silicon nitride materials (SiCN), silicon oxide (SiO₂), tetra-ethyl-ortho-silicate (TEOS) based oxide, and combinations thereof.

15. The method of claim 12, further comprising a hard mask material layer deposited between the bulk dielectric insulating layer and the first resist material layer, wherein the hard mask material layer comprises a material selected from the group consisting of tantalum, titanium, tungsten, tantalum nitride, titanium nitride, tungsten nitride, amorphous silicon, and combinations thereof, deposited over the dielectric film stack

16. The method of claim 12, further comprising annealing the surface of the substrate after the one or more trenches and one or more vias are formed.

17. The method of claim 12, further comprising depositing an additional organic fill material layer between the mask layer and the second resist material layer.

18. A method of forming a dual damascene structure on the surface of a substrate having a bottom barrier layer, a bulk dielectric insulating layer, and a first resist material layer deposited thereon, comprising:

performing trench lithography on the first resist material layer to form a trench pattern thereon prior to performing via lithography on a second resist material layer to form a via pattern thereon;

etching the bulk dielectric insulating layer until an desired etching depth to define one or more trenches therein according to the trench pattern on the first resist material layer;

filling the one or more trenches with an organic material, wherein the second resist material layer is applied over a mask layer deposited over the organic material;

etching the mask layer, the organic material, and the bulk dielectric insulating layer to define one or more vias therein according to the via pattern on the second resist material layer;

etching the bottom barrier layer to form the one or more vias therein according to the via pattern;

removing the organic material from the organic material filled trenches and the one or more vias; and

forming the one or more trenches and one or more vias therein the dielectric film stack on the surface of the substrate.

19. The method of claim 18, wherein the bulk dielectric insulating layer comprises a low K dielectric material selected from the group consisting of organosilicate materials, porous oxide materials, silsesquioxane materials, paralyne, polymer materials, benzocyclobutene, polytetrafluoroethylene, parylene, polyether, polyimide, polyamide materials, carbon-doped dielectrics materials, carbon-doped organo-silicate glass (OSG) materials, carbon-doped silicon dioxides, spin-on glass materials, un-doped silicon glass (USG) materials, fluorine-doped silicon glass (FSG) materials, carbon containing silicon materials, silicon oxycarbides (SiOC), and combinations thereof.

20. The method of claim 18, further comprising one or more top dielectric material layers deposited between the bulk dielectric insulating layer and the first resist material layer, wherein the one or more top dielectric material layers comprises a material selected from the group consisting of silicon oxynitrides (SiON), carbon containing silicon materials, silicon oxycarbides (SiOC), silicon carbides, silicon nitrides (SiN), carbon containing silicon nitride materials (SiCN), silicon oxide (SiO₂), tetra-ethyl-ortho-silicate (TEOS).based oxide, and combinations thereof.

21. The method of claim 18, further comprising a hard mask material layer deposited between the bulk dielectric insulating layer and the first resist material layer