Method for curing a dielectric film

• US 20090075491A1
• Filed: 09/13/2007
• Published: 03/19/2009
• Est. Priority Date: 09/13/2007
• Status: Abandoned Application

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: LEE, Eric, TOMA, Dorel I., LIU, Junjun
• Application Number:
  US11/854,937
• Publication Number:
  US 20090075491A1
• Time in Patent Office: Days
• US Class Current: 438/800
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/31058 of organic layers
• CPC Class Codes: H01L 21/67115 mainly by radiation

Abstract

A method of curing a low dielectric constant (low-k) dielectric film on a substrate is described, wherein the dielectric constant of the low-k dielectric film is less than a value of approximately 4. The method comprises exposing the low-k dielectric film to ultraviolet (UV) radiation. Following the UV exposure, the dielectric film is exposed to IR radiation.

Claims

1. A method of curing a low dielectric constant (low-k) dielectric film on a substrate, comprising:

disposing a substrate having a low-k dielectric film in a curing system;

exposing said low-k dielectric film to ultraviolet (UV) radiation in said curing system;

following said UV exposure, exposing said low-k dielectric film to infrared (IR) radiation; and

reducing a refractive index of said low-k dielectric film during said exposing said low-k dielectric film to said infrared (IR) radiation,

wherein the dielectric constant of said low-k dielectric film is less than a value of approximately 4.

2. The method of claim 1, further comprising:

during said IR exposure, heating said low-k dielectric film by elevating the temperature of said substrate to a thermal treatment temperature ranging from approximately 200 degrees C to approximately 600 degrees C.

3. The method of claim 2, wherein said thermal treatment temperature ranges from approximately 350 degrees C to approximately 450 degrees C.

4. The method of claim 1, further comprising:

during said UV exposure, heating said low-k dielectric film by elevating the temperature of said substrate to a cure temperature ranging from approximately 200 degrees C to approximately 600 degrees C.

5. The method of claim 4, wherein said cure temperature ranges from approximately 300 degrees C to approximately 500 degrees C.

6. The method of claim 1, wherein said IR exposure is performed in a process system different from said curing system.

7. The method of claim 1, wherein said exposing said dielectric film to UV radiation comprises exposing said dielectric film to UV radiation from one or more UV lamps, one or more UV LEDs, or one or more UV lasers, or a combination of two or more thereof.

8. The method of claim 1, wherein said exposing said dielectric film to UV radiation comprises exposing said dielectric film to UV radiation with a wavelength ranging from approximately 100 nanometers to approximately 600 nanometers.

9. The method of claim 1, wherein said exposing said dielectric film to UV radiation comprises exposing said dielectric film to UV radiation with a wavelength ranging from approximately 200 nanometers to approximately 400 nanometers.

10. The method of claim 1, wherein said exposing said dielectric film to IR radiation comprises exposing said dielectric film to IR radiation from one or more IR lamps, one or more IR LEDs, or one or more IR lasers, or a combination of two or more thereof.

11. The method of claim 1, wherein said exposing said dielectric film to IR radiation comprises exposing said dielectric film to IR radiation with a wavelength ranging from approximately 1 micron to approximately 25 microns.

12. The method of claim 1, wherein said exposing said dielectric film to IR radiation comprises exposing said dielectric film to IR radiation with a wavelength ranging from approximately 8 microns to approximately 14 microns.

13. The method of claim 1, wherein said exposing said dielectric film to UV radiation further comprises:

exposing said dielectric film to IR radiation during at least a portion of said UV exposure.

14. The method of claim 13, wherein said exposing said dielectric film to IR radiation comprises exposing said dielectric film to IR radiation ranging from approximately 8 microns to approximately 14 microns.

15. The method of claim 1, further comprising:

prior to said UV exposure, disposing said substrate in a drying system;

drying said dielectric film according to a drying process in order to remove or partially remove contaminants on or in said dielectric film; and

transferring said substrate from said drying system to said curing system while maintaining vacuum conditions during said transfer.

16. The method of claim 1, further comprising:

treating said dielectric film following said IR exposure by performing one or more of depositing another film on said dielectric film, cleaning said dielectric film, or exposing said dielectric film to plasma.

17. The method of claim 1, wherein the dielectric constant of said low-k dielectric film is less than or equal to a value of approximately 2.5.

18. The method of claim 17, wherein said low-k dielectric film comprises an inorganic dielectric film, an organic dielectric film, a hybrid organic-inorganic dielectric film, a porous dielectric film, or a non-porous dielectric film, or a combination of two or more thereof.

19. The method of claim 1, wherein said low-k dielectric film comprises a siloxane-based organosilicate low-k material, and wherein said UV radiation includes a wavelength ranging from about 200 nm to about 300 nm and said IR radiation includes a wavelength ranging from about 9 microns to about 10 microns.

20. A computer readable medium containing program instructions for execution on a control system, which when executed by the control system, cause a curing system to perform the steps of:

disposing a substrate having a low-k dielectric film in a curing system;

exposing said low-k dielectric film to ultraviolet (UV) radiation in said curing system;

following said UV exposure, exposing said low-k dielectric film to infrared (IR) radiation; and

reducing a refractive index of said low-k dielectric film during said exposing said low-k dielectric film to said infrared (IR) radiation,

wherein the dielectric constant of said low-k dielectric film is less than a value of approximately 4.