Precursor and Process Design for Photo-Assisted Metal Atomic Layer Deposition (ALD) and Chemical Vapor Deposition (CVD)

• US 20170058401A1
• Filed: 03/27/2014
• Published: 03/02/2017
• Est. Priority Date: 03/27/2014
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: SIMKA, Harsono S., ZIMMERMAN, Paul A., BLACKWELL, James M., ROMERO, Patricio E., CLENDENNING, Scott B., KLOSTER, Grant M., GSTREIN, Florian, BRISTOL, Robert L.
• Granted Patent: US 9,932,671 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C23C 16/18 from metallo-organic compounds
• CPC Class Codes: C23C 16/45553 characterized by the use of precursors specially adapted for ALD
• CPC Class Codes: C23C 16/482 using incoherent light, UV to IR, e.g. lamps
• CPC Class Codes: H01L 21/0337 characterised by the process involved to create the mask, e.g. lift-off masks, sidewalls, or to modify the mask, e.g. pre-treatment, post-treatment
• CPC Class Codes: H01L 21/28556 by chemical means, e.g. CVD, LPCVD, PECVD, laser CVD H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/28562 Selective deposition
• 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 21/76879 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 29/66795 with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET

Abstract

Precursor and process design for photo-assisted metal atomic layer deposition (ALD) and chemical vapor deposition (CVD) is described. In an example, a method of fabricating a thin metal film involves introducing precursor molecules proximate to a surface on or above a substrate, each of the precursor molecules having one or more metal centers surrounded by ligands. The method also involves depositing a metal layer on the surface by dissociating the ligands from the precursor molecules using a photo-assisted process.

Claims

1. A method of fabricating a thin metal film, the method comprising:

introducing precursor molecules proximate to a surface on or above a substrate, each of the precursor molecules comprising one or more metal centers surrounded by ligands; and

depositing a metal layer on the surface by dissociating the ligands from the precursor molecules using a photo-assisted process.

2. The method of claim 1, wherein dissociating the ligands from the precursor molecules using the photo-assisted process comprises using a direct photo-assisted process involving delivery of photons directly to the precursor molecules.

3. The method of claim 2, wherein using the direct photo-assisted process comprises irradiating at a first wavelength of light to dissociate a first portion of the ligands and, subsequently, irradiating at a second wavelength of light to dissociate the remaining of the ligands.

4. The method of claim 1, wherein dissociating the ligands from the precursor molecules using the photo-assisted process comprises using an indirect photo-assisted process involving delivery of photons first to chromophores anchored to the surface, and then from the chromophores to the precursor molecules.

5. The method of claim 1, wherein depositing the metal layer on the surface comprises depositing selectively on the surface without depositing on an adjacent, different, surface.

6. The method of claim 1, wherein depositing the metal layer on the surface comprises forming the metal layer to a thickness approximately equal to or less than 3 nanometers.

7. The method of claim 1, wherein using the photo-assisted process comprises irradiating at a wavelength of light approximately in the range of 150-800 nanometers.

8. The method of claim 1, wherein depositing the metal layer comprises performing the deposition at a temperature approximately in the range of 25-200 degrees Celsius.

9. A method of fabricating an interconnect structure for an integrated circuit, the method comprising:

providing a previous layer metallization structure comprising an alternating metal line and dielectric line first grating pattern having a first direction;

forming a dielectric line second grating pattern above the previous layer metallization structure, the dielectric line second grating pattern having a second direction, perpendicular to the first direction;

forming a sacrificial structure above the first grating pattern and between the dielectric lines of the second grating pattern;

replacing portions of the sacrificial structure above and aligned with the metal lines of the first grating pattern with a first dielectric layer, and replacing portions of the sacrificial structure above and aligned with the dielectric lines of the first grating pattern with a second dielectric layer;

forming, by using a photo-assisted process, at least a portion of one or more conductive vias in the first dielectric layer, on a surface of exposed portions of the metal lines of the first grating pattern, wherein using the photo-assisted process comprises;

introducing precursor molecules proximate to the surface of the exposed portions of the metal lines, each of the precursor molecules comprising one or more metal centers surrounded by ligands; and

depositing a metal layer on the surface of the exposed portions of the metal lines by dissociating the ligands from the precursor molecules using photo-dissociation;

recessing portions of the first and second dielectric layers; and

forming a plurality of metal lines in the recessed portions of the first and second dielectric layers, coupled with the one or more conductive vias, the plurality of metal lines having the second direction.

10. The method of claim 9, wherein dissociating the ligands from the precursor molecules using photo-dissociation comprises using a direct photo-dissociation process involving delivery of photons directly to the precursor molecules.

11. The method of claim 10, wherein using the direct photo-dissociation comprises irradiating at a first wavelength of light to dissociate a first portion of the ligands and, subsequently, irradiating at a second wavelength of light to dissociate the remaining of the ligands.

12. The method of claim 9, wherein dissociating the ligands from the precursor molecules using photo-dissociation comprises using an indirect photo-dissociation process involving delivery of photons first to chromophores anchored to the surface of the exposed portions of the metal lines, and then from the chromophores to the precursor molecules.

13. The method of claim 9, wherein depositing the metal layer on the surface of the exposed portions of the metal lines comprises depositing selectively on the surface of the exposed portions of the metal lines without depositing on an adjacent, different, surfaces.

14. The method of claim 9, wherein depositing the metal layer on the surface of the exposed portions of the metal lines comprises forming the metal layer to a thickness approximately equal to or less than 3 nanometers.

15. The method of claim 9, wherein using the photo-assisted process comprises irradiating at a wavelength of light approximately in the range of 150-800 nanometers.

16. The method of claim 9, wherein depositing the metal layer comprises performing the deposition at a temperature approximately in the range of 25-200 degrees Celsius.

17. A method of fabricating a semiconductor device, the method comprising:

forming one or more semiconductor fins above a substrate;

forming a gate dielectric layer conformal with the one or more semiconductor fins;

forming a gate electrode conformal with the gate dielectric layer, wherein forming at least a portion of the gate electrode comprises;

introducing precursor molecules proximate to a surface on or above the gate dielectric layer, each of the precursor molecules comprising one or more metal centers surrounded by ligands; and

depositing a metal layer on the surface by dissociating the ligands from the precursor molecules using a photo-assisted process; and

forming source and drain regions in the one or more semiconductor fins, on either side of the gate electrode.

18. The method of claim 17, wherein dissociating the ligands from the precursor molecules using the photo-assisted process comprises using a direct photo-assisted process involving delivery of photons directly to the precursor molecules.

19. The method of claim 18, wherein using the direct photo-assisted process comprises irradiating at a first wavelength of light to dissociate a first portion of the ligands and, subsequently, irradiating at a second wavelength of light to dissociate the remaining of the ligands.

20. The method of claim 17, wherein dissociating the ligands from the precursor molecules using the photo-assisted process comprises using an indirect photo-assisted process involving delivery of photons first to chromophores anchored to the surface, and then from the chromophores to the precursor molecules.

21. The method of claim 17, wherein depositing the metal layer on the surface comprises depositing selectively on the surface without depositing on an adjacent, different, surface.

22. The method of claim 17, wherein depositing the metal layer on the surface comprises forming the metal layer to a thickness approximately equal to or less than 3 nanometers.

23. The method of claim 17, wherein using the photo-assisted process comprises irradiating at a wavelength of light approximately in the range of 150-800 nanometers.

24. The method of claim 17, wherein depositing the metal layer comprises performing the deposition at a temperature approximately in the range of 25-200 degrees Celsius.