Ultraviolet assisted pore sealing of porous low k dielectric films
View Patent ↗Processes for sealing porous low k dielectric film generally comprises exposing the porous surface of the porous low k dielectric film to ultraviolet (UV) radiation at intensities, times, wavelengths and in an atmosphere effective to seal the porous dielectric surface by means of carbonization, oxidation, and/or film densification. The surface of the surface of the porous low k material is sealed to a depth less than or equal to about 20 nanometers, wherein the surface is substantially free of pores after the UV exposure.
1. A process for sealing a surface of an interlayer dielectric comprising a porous low k dielectric material disposed on a substrate, comprising:
forming and patterning the interlayer dielectric comprising the porous low k dielectric material; and
subsequently exposing the porous low k dielectric material to an ultraviolet radiation pattern for a period of time, intensity, and wavelength effective to seal the surface of the interlayer dielectric to a depth less than or equal to about 20 nanometers prior to depositing additional layers and/or prior to further processing, wherein the surface is substantially free of open pores and the porous low k dielectric material has a dielectric constant less than 4.
2. The process of claim 1 , wherein the ultraviolet radiation pattern comprises broadband wavelengths less than 400 nanometers.
3. The process of claim 1 , wherein the ultraviolet radiation pattern comprises broadband wavelengths between about 100 and 400 nanometers.
4. The process of claim 1 , wherein exposing the surface of the porous low k dielectric material to the ultraviolet radiation pattern for a period of time, intensity and wavelength is in a reactive purge environment.
5. The process of claim 1 , wherein exposing the surface of the porous low k dielectric material to the ultraviolet radiation pattern is in an atmosphere of N 2 , H 2 , Ar, He, Ne, H 2 O vapor, NH 3 , CO, CO 2 , O 2 , O 3 , C x H y , C x F y , C x H z F y , and mixtures thereof, wherein x is an integer between 1 and 6, y is an integer between 4 and 14, and z is an integer between 1 and 14.
6. The process of claim 1 , wherein exposing the porous low k dielectric material the ultraviolet radiation pattern is for a period of time, intensity, and wavelength effective to seal a surface of the porous low k material to a depth less than or equal to about 10 nanometers.
7. The process of claim 1 , wherein exposing the porous low k dielectric material the ultraviolet radiation pattern is for a period of time, intensity and wavelength effective to seal a surface of the porous low k material to a depth about equal to an average pore diameter.
8. A process for forming an electrical interconnect structure, comprising:
patterning an interlayer dielectric comprising a porous low k dielectric material disposed on a substrate;
exposing the porous low k dielectric film subsequent to patterning to ultraviolet radiation for a period of time, intensity, and wavelength pattern effective to seal the surface of the interlayer dielectric to a depth less than or equal to about 20 nanometers prior to depositing additional layers and/or prior to further processing, wherein the surface is substantially free of open pores and the porous low k dielectric material has a dielectric constant less than 4; and
depositing a barrier layer and/or a conductive layer onto the patterned interlayer dielectric, wherein the barrier layer is substantially free of pinholes.
9. The process according to claim 8 , further comprising depositing the barrier layer onto the porous low k dielectric material prior to depositing the conductive layer.
10. The process according to claim 8 , wherein the ultraviolet radiation comprises broadband wavelengths of less than 400 nanometers.
11. The process according to claim 8 , wherein the ultraviolet exposure is performed in an atmosphere of N 2 , H 2 , Ar, He, Ne, H 2 O vapor, NH 3 , CO, CO 2 , O 2 , O 3 , C x H y , C x F y , C x H z F y , and mixtures thereof, wherein x is an integer between 1 and 6, y is an integer between 4 and 14, and z is an integer between 1 and 14.
12. A process for sealing an interlayer dielectric comprising a porous low k dielectric material disposed on a substrate, the process comprising:
forming and patterning the interlayer dielectric comprising the porous low k dielectric material; and
subsequently oxidizing a surface of the interlayer dielectric by exposing the porous low k dielectric material to an ultraviolet radiation pattern for a period of time, intensity, and wavelength effective in an atmosphere comprising oxygen to seal the surface of the interlayer dielectric to a depth less than or equal to about 20 nanometers prior to depositing additional layers and/or prior to further processing, wherein the porous low k dielectric material has a dielectric constant less than 4.
13. The process according to claim 12 , wherein the ultraviolet radiation pattern comprises broadband wavelengths of less than 400 nanometers.
14. The process according to claim 12 , further comprising annealing the porous low k dielectric material after exposing the porous low k dielectric material to the ultraviolet radiation.
15. A process for sealing an interlayer dielectric comprising a porous low k dielectric material disposed on a substrate, the process comprising:
forming and patterning the interlayer dielectric comprising the porous low k dielectric material; and
subsequently carbonizing a surface of the interlayer dielectric by exposing the porous low k dielectric material to an ultraviolet radiation pattern for a period of time, intensity and wavelength effective to seal the surface of the interlayer dielectric to a depth less than or equal to about 20 nanometers prior to depositing additional layers and/or prior to further processing, wherein the porous low k dielectric material has a dielectric constant less than 4.
16. The process according to claim 15 , wherein the ultraviolet radiation comprises broadband wavelengths of less than 400 nanometers.
17. The process according to claim 15 , further comprising annealing the porous low k dielectric material after exposing the porous low k dielectric material to the ultraviolet radiation.
18. A process for sealing an interlayer dielectric comprising a porous low k dielectric material disposed on a substrate, the process comprising:
forming and patterning the interlayer dielectric comprising the porous low k dielectric material; and
subsequently densifying a surface of the interlayer dielectric by exposing the porous low k dielectric material to an ultraviolet radiation pattern for a period of time, intensity, and wavelength effective to seal the surface of the interlayer dielectric to a depth less than or equal to about 20 nanometers prior to depositing additional layers and/or prior to further processing, wherein the porous low k dielectric material has a dielectric constant less than 4.
19. The process according to claim 18 , wherein the ultraviolet radiation comprises broadband wavelengths of less than 400 nanometers.
20. The process according to claim 19 , further comprising annealing the porous low k dielectric material after exposing the porous low k dielectric material to the ultraviolet radiation.