Method of depositing an amorphous carbon layer

• US 6,841,341 B2
• Filed: 12/17/2002
• Issued: 01/11/2005
• Est. Priority Date: 02/17/2000
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Weidman, Timothy, Rice, Michael, Bencher, Christopher Dennis, Fairbairn, Kevin, Latchford, Ian Scot, Ngai, Christopher S, Wang, Yuxiang May
• Primary Examiner(s): WALKE, AMANDA C
• Application Number:
  US10/322,228
• Publication Number:
  US 20030091938A1
• Time in Patent Office: 756 Days
• Field of Search: 430/311, 430/314, 430/315, 430/317, 430/322, 430/323, 430/324
• US Class Current: 430/323
• CPC Class Codes: C23C 16/26 Deposition of carbon only
• CPC Class Codes: H01L 21/02115 the material being carbon, e.g. alpha-C, diamond or hydrogen doped carbon
• 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 21/02205 the layer being characterised by the precursor material for deposition
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0276 using an anti-reflective coating anti-reflective coating for lithography in general G03F7/09
• CPC Class Codes: H01L 21/28035 the final conductor layer next to the insulator being silicon, e.g. polysilicon, with or without impurities H01L21/28105 takes precedence
• CPC Class Codes: H01L 21/3081 characterised by their composition, e.g. multilayer masks, materials
• CPC Class Codes: H01L 21/3088 Process specially adapted to improve the resolution of the mask
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: H01L 21/31144 using masks
• CPC Class Codes: H01L 21/3146 Carbon layers, e.g. diamond-like layers
• CPC Class Codes: H01L 21/31612 on a silicon body
• CPC Class Codes: H01L 21/32137 of silicon-containing layers
• 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 21/76829 characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers

Abstract

A method of forming an integrated circuit using an amorphous carbon film. The amorphous carbon film is formed by thermally decomposing a gas mixture comprising a hydrocarbon compound and an inert gas. The amorphous carbon film is compatible with integrated circuit fabrication processes. In one integrated circuit fabrication process, the amorphous carbon film is used as a hardmask. In another integrated circuit fabrication process, the amorphous carbon film is an anti-reflective coating (ARC) for deep ultraviolet (DUV) lithography. In yet another integrated circuit fabrication process, a multi-layer amorphous carbon anti-reflective coating is used for DUV lithography.

Claims

1. A method of processing a substrate, comprising:

forming a dielectric layer on the substrate;

forming a hardmask comprising one or more amorphous carbon layers on the dielectric layer by a chemical vapor deposition technique;

forming an intermediate layer on the hardmask, wherein the intermediate layer comprises silicon carbide;

defining a pattern in at least one region of the intermediate layer; and

defining a pattern in at least one region of the hardmask.

2. The method of claim 1, further comprising transferring the pattern defined in the at least one region of the hardmask into the substrate.

3. The method of claim 2, further comprising removing the hardmask from the substrate.

4. The method of claim 1, wherein definition of the pattern in the at least one region of the hardmask, comprises:

forming a layer of energy sensitive resist material on the intermediate layer;

introducing an image of the pattern into the layer of energy sensitive resist material by exposing the energy sensitive resist material to patterned radiation;

developing the image of the pattern introduced into the layer of energy sensitive resist material; and

transferring the pattern through the hardmask.

5. The method of claim 4, wherein the defining a pattern in at least one region of the intermediate layer comprises

forming an energy sensitive resist thereon;

introducing the image of a pattern therein;

developing the image of the pattern; and

transferring the image of the pattern developed in the layer of energy sensitive resist material through the intermediate layer.

6. The method of claim 5, wherein the intermediate layer is an oxide.

7. The method of claim 3, wherein the one or more amorphous carbon layers are removed from the substrate using an ozone, oxygen, or ammonia plasma.

8. The method of claim 1, wherein the one or more amorphous carbon layers each have an absorption coefficient in the range of about 0.1 to about 1.0 at wavelengths less than about 250 nm and wherein the one or more amorphous carbon layers each have an index of refraction in the range of about 1.5 to about 1.9.

9. The method of claim 1, wherein the one or more amorphous carbon layers are formed on the substrate by:

positioning the substrate in a deposition chamber;

providing a gas mixture to the deposition chamber, wherein the gas mixture comprises one or more hydrocarbon compounds and an inert gas; and

applying an electric field of a radio frequency (RF) power in a range of about 3 W/in² to about 20 W/in² to react the one or more hydrocarbon compounds in the gas mixture to form the one or more amorphous carbon layers on the substrate.

10. The method of claim 9, wherein the gas mixture further comprises an additive gas.

11. The method of claim 9, wherein the deposition chamber is maintained at a pressure between about 1 Torr to about 20 Torr.

12. The method of claim 1, further comprising depositing one or more conductive material on the substrate surface.

13. A method of fabricating a damascene structure, comprising

forming a dielectric layer on a substrate;

forming an amorphous carbon layer on the dielectric layer;

patterning the amorphous carbon layer to define contacts/vias therethrough;

transferring the pattern formed in the amorphous carbon layer through the dielectric layer to form contacts/vias therein;

removing the amorphous carbon layer from the patterned dielectric layer; and

filling the contacts/vias formed in the dielectric layer with a conductive material.

14. The method of claim 13, wherein the dielectric layer is selected from the group consisting of silicon dioxide and fluorosilicate glass.

15. The method of claim 13, wherein the conductive material filling the contacts/vias is selected from the group consisting of copper, aluminum, tungsten, and combinations thereof.

16. The method of claim 13, wherein the amorphous carbon layer is formed on the dielectric layer by

positioning the substrate in a deposition chamber, wherein the substrate has a dielectric layer thereon;

providing a gas mixture to the deposition chamber, wherein the gas mixture comprises one or more hydrocarbon compounds and an inert gas; and

applying an electric field of a radio frequency (RF) power in a range of about 3 W/in² to about 20 W/in² to react the one or more hydrocarbon compounds in the gas mixture to form the amorphous carbon layer on the dielectric layer.

17. The method of claim 16, wherein the gas mixture further comprises an additive gas selected from the group consisting of ammonia, nitrogen, hydrogen, and combinations thereof.

18. The method of claim 16, wherein the deposition chamber is maintained at a pressure between about 1 Torr to about 20 Torr.

19. The method of claim 16, wherein the amorphous carbon layer has an absorption coefficient in the range of about 0.1 to about 1.0 at wavelengths less than about 250 nm and wherein the one or more amorphous carbon layers each have an index of refraction in the range of about 1.5 to about 1.9.