Method for producing self-aligned mask, articles produced by same and composition for same
View Patent ↗A method for forming a self-aligned pattern on an existing pattern on a substrate comprising applying a coating of a solution containing a masking material in a carrier, the masking material being either photo or thermally sensitive; performing a blanket exposure of the substrate; and allowing at least a portion of the masking material to preferential develop in a fashion that is replicates the existing pattern of the substrate. The existing pattern may be comprised of a first set of regions of the substrate having a first reflectivity and a second set of regions of the substrate having a second reflectivity different from the first composition. The first set of regions may include one or more metal elements and the second set of regions may include a dielectric. Structures made in accordance with the method.
1. A method for forming a self-aligned pattern comprising:
providing a substrate having an existing pattern formed therein,
applying a masking material directly to an upper surface of said substrate and directly to an upper surface of said existing pattern,
exposing the masking material to a blanket exposure with a sufficient dose to generate a response in the masking material, and
developing the exposed masking material to reveal a mask pattern commensurate with a spatial intensity distribution generated during the blanket exposure.
2. The method of claim 1 , wherein said existing pattern on the substrate is comprised of a first set of regions having a first atomic composition and a second set of regions having a second atomic composition different from the first composition.
3. The method of claim 2 , wherein said first set of regions comprises one or more metallic or conductive elements and wherein said second set of regions comprises a dielectric.
4. The method of claim 1 , wherein said masking material is comprised of a positive tone photoresist, a negative tone photoresist, a positive tone thermal resist, or a negative tone thermal resist.
5. The method of claim 1 , wherein the substrate comprises two or more regions of different reflectivity adjacent to one another.
6. The method of claim 1 , wherein the substrate comprises two or more regions of different absorbance adjacent to one another.
7. The method of claim 1 , wherein the substrate comprises two or more regions of different transparency adjacent to one another.
8. The method of claim 1 , wherein the developed masking material is further exposed to a dry etch process.
9. The method of claim 1 , wherein blanket exposure is performed at a wavelength of less than 2 microns.
10. The method of claim 1 , wherein the blanket exposure is performed using two distinct wavelengths for which the masking material is sensitive.
11. The method of claim 1 , wherein the masking material has a thickness equal to a minima or maxima in a plot of reflectivity versus resist film thickness for one or more of the surfaces of interest.
12. The method of claim 1 , wherein the masking material has a thickness that maximizes the difference in the thickness of the masking material in a plot of film thickness versus exposure dose for one or more of the surfaces of interest.
13. The method of claim 12 , wherein the masking material has a thickness that maximizes the difference in the thickness of the masking material in a plot of film thickness versus exposure dose for one or more of the surfaces of interest and has a thickness of zero over one or more of the surfaces of interest.
14. The method of claim 1 , wherein said masking material is a positive-tone material, and said developing provides a patterned masking material directly atop portions of the substrate not including said existing pattern, and wherein the upper surface of said existing pattern is exposed.
15. The method of claim 14 , further comprising:
forming a material layer directly on the exposed upper surface of said existing pattern, and
removing said patterned masking material to provide a structure in which said material layer has vertical sidewalls that are vertical coincident with sidewalls of said existing pattern.
16. The method of claim 1 , wherein said masking material is a negative-tone material, and said developing provides a patterned masking material directly atop the upper surface of the existing pattern, and wherein surface portions of the substrate not including said existing pattern are exposed.
17. The method of claim 16 , further comprising:
forming a sacrificial material atop the exposed surface portions of the substrate not including said existing pattern,
removing the patterned masking material from atop the upper surface of the existing pattern,
forming a material layer directly on the exposed upper surface of said existing pattern, and
removing said sacrificial material to provide a structure in which said material layer has vertical sidewalls that are vertical coincident with sidewalls of said existing pattern.