Double patterning method
Disclosed is an improved double patterning method for forming openings (e.g., vias or trenches) or mesas on a substrate. This method avoids the wafer topography effects seen in prior art double patterning techniques by ensuring that the substrate itself is only subjected to a single etch process. Specifically, in the method, a first mask layer is formed on the substrate and processed such that it has a doped region and multiple undoped regions within the doped region. Then, either the undoped regions or the doped region can be selectively removed in order to form a mask pattern above the substrate. Once the mask pattern is formed, an etch process can be performed to transfer the mask pattern into the substrate. Depending upon whether the undoped regions are removed or the doped region is removed, the mask pattern will form openings (e.g., vias or trenches) or mesas, respectively, on the substrate.
1. A computer program product comprising a non-transitory computer-readable storage medium storing computer-readable program code, said computer-readable program code comprising instructions that, when executed by a computer, cause manufacturing equipment to perform a method, said method comprising:
forming a first mask layer on a substrate;
performing at least two dopant implantation processes to form, within said first mask layer, a doped region that comprises a dopant and that laterally surrounds multiple undoped region;
selectively removing said doped region to form a mask pattern above said substrate; and,
performing an etch process to transfer said mask pattern into said substrate to form multiple discrete features in said substrate,
said dopant comprising phosphorous.
2. The computer program product of claim 1 , said performing of said at least two dopant implantation processes comprising:
forming a second mask layer on said first mask layer, said second mask layer being patterned so that first portions of said first mask layer are exposed;
doping said first portions with said dopant;
removing said second mask layer;
forming a third mask layer on said first mask layer, said third mask layer being patterned such that second portions of said first mask layer, which traverse said first portions, are exposed;
doping said second portions with said dopant such that said first portions and said second portions in combination form said doped region that comprises said dopant and that laterally surrounds said multiple undoped regions; and,
removing said third mask layer.
3. The computer program product of claim 2 , said second mask layer and said third mask layer each being formed such that, following said doping of said first portions and said doping of said second portions, said multiple undoped regions each have a same size and shape.
4. The computer program product of claim 2 , said second mask layer and said third mask layer each being formed such that, following said doping of said first portions and said doping of said second portions, at least some of said multiple undoped regions have any of different sizes and different shapes.
5. The computer program product of claim 2 , said second mask layer being patterned into a strip mask pattern and said third mask layer being patterned into an additional strip mask pattern oriented at a different angle than said stripe mask pattern, said stripe mask pattern and said additional stripe mask pattern each comprising a plurality of parallel rectangular-shaped bodies and said parallel rectangular-shaped bodies having identical dimensions and spacing in said stripe mask pattern and said additional stripe mask pattern.
6. The computer program product of claim 2 , said second mask layer being patterned into a strip mask pattern and said third mask layer being patterned into an additional strip mask pattern oriented at a different angle than said stripe mask pattern, said stripe mask pattern and said additional stripe mask pattern each comprising a plurality of parallel rectangular-shaped bodies and said parallel rectangular-shaped bodies having any one of varied dimensions and varied spacing in said stripe mask pattern and said additional stripe mask pattern.
7. The computer program product of claim 1 , said first mask layer comprising any one of an amorphous semiconductor layer and a polycrystalline semiconductor layer and said substrate comprising any one of a dielectric, a conductor and a semiconductor.
8. The computer program product of claim 2 , said second mask layer and said third mask layer being patterned using lithographic patterning techniques and comprising photoresist layers.
9. The computer program product of claim 2 , said second mask layer and said third mask layer being patterning using sidewall image transfer patterning techniques and comprising dielectric layers.
10. A computer program product comprising a non-transitory computer-readable storage medium storing computer-readable program code, said computer-readable program code comprising instructions that, when executed by a computer, cause manufacturing equipment to perform a method, said method comprising:
forming a first mask layer on a substrate;
performing at least two dopant implantation processes to form, within said first mask layer, a doped region that comprises a dopant and that laterally surrounds multiple undoped regions;
selectively removing said multiple undoped regions to form a mask pattern above said substrate; and,
performing an etch process to transfer said mask pattern into said substrate to form multiple openings in said substrate,
said dopant comprising xenon.
11. The computer program product of claim 10 , said performing of said at least two dopant implantation processes comprising:
forming a second mask layer on said first mask layer, said second mask layer being patterned such that first portions of said first mask layer are exposed;
doping said first portions with said dopant;
removing said second mask layer;
forming a third mask layer on said first mask layer, said third mask layer being patterned such that second portions of said first mask layer, which traverse said first portions, are exposed;
doping said second portions with said dopant such that said first portions and said second portions in combination form said doped region that comprises said dopant and that laterally surrounds said multiple undoped regions; and,
removing said third mask layer.
12. The computer program product of claim 11 , said second mask layer and said third mask layer each being formed such that, following said doping of said first portions and said doping of said second portions, said multiple undoped regions each have a same size and shape.
13. The computer program product of claim 11 , said second mask layer and said third mask layer each being formed such that, following said doping of said first portions and said doping of said second portions, at least some of said multiple undoped regions have any of different sizes and different shapes.
14. The computer program product of claim 11 , said second mask layer being patterned into a strip mask pattern and said third mask layer being patterned into an additional strip mask pattern oriented at a different angle than said stripe mask pattern, said stripe mask pattern and said additional stripe mask pattern each comprising a plurality of parallel rectangular-shaped bodies and said parallel rectangular-shaped bodies having identical dimensions and spacing in said stripe mask pattern and said additional stripe mask pattern.
15. The computer program product of claim 11 , said second mask layer being patterned into a strip mask pattern and said third mask layer being patterned into an additional strip mask pattern oriented at a different angle than said stripe mask pattern, said stripe mask pattern and said additional stripe mask pattern each comprising a plurality of parallel rectangular-shaped bodies and said parallel rectangular-shaped bodies having any one of varied dimensions and varied spacing in said stripe mask pattern and said additional stripe mask pattern.
16. The computer program product of claim 10 , said first mask layer comprising any one of amorphous silicon and polycrystalline silicon and said substrate comprising any one of a dielectric, a conductor and a semiconductor.
17. The computer program product of claim 11 , said second mask layer and said third mask layer being patterned using lithographic patterning techniques and comprising photoresist layers.
18. The computer program product of claim 11 , said second mask layer and said third mask layer being patterning using sidewall image transfer patterning techniques and comprising dielectric layers.
19. A computer program product comprising a non-transitory computer-readable storage medium storing computer-readable program code, said computer-readable program code comprising instructions that, when executed by a computer, cause manufacturing equipment to perform a method, said method comprising:
forming a first mask layer on a substrate, said substrate comprising a conductor layer;
performing at least two dopant implantation processes to form, within said first mask layer, a doped region that comprises a dopant and that laterally surrounds multiple undoped regions, said performing of said at least two dopant implantation processes comprising:
forming a second mask layer on said first mask layer, said second mask layer being patterned such that first portions of said first mask layer are exposed;
doping said first portions with said dopant;
removing said second mask layer;
forming a third mask layer on said first mask layer such that second portions of said first mask layer are exposed;
doping said second portions with said dopant such that said first portions and said second portions in combination form said doped region that comprises said dopant and that laterally surrounds said multiple undoped regions; and,
removing said third mask layer;
selectively removing said doped region to form a mask pattern above said substrate; and
performing an etch process to transfer said mask pattern into said substrate so as to form multiple discrete nanowires in said conductor layer.
20. The computer program product of claim 19 , and said dopant comprising any of arsenic and phosphorous and said first mask layer comprising any one of amorphous silicon and polycrystalline silicon.