Methods for uniform imprint pattern transfer of sub-20 nm features
View Patent ↗Methods of increasing etch selectivity in imprint lithography are described which employ material deposition techniques that impart a unique morphology to the multi-layer material stacks, thereby enhancing etch process window and improving etch selectivity. For example, etch selectivity of 50:1 or more between patterned resist layer and deposited metals, metalloids, or non-organic oxides can be achieved, which greatly preserves the pattern feature height prior to the etch process that transfers the pattern into the substrate, allowing for sub-20 nm pattern transfer at high fidelity.
1. An imprint lithography method comprising the steps of:
imprinting a patterned layer of an organic polymerized material on a substrate, the patterned layer having a residual layer and one or more protrusions and recessions defining features of the patterned layer, with the protrusions extending from the residual layer a height of 20 nm or less and having an aspect ratio of 1.5:1 to 3:1;
depositing an etch selective material onto at least the protrusions and the recessions of the patterned layer, the etch selective material comprising a metal, metalloid or non-organic oxide having an etch selectivity of 50:1 or more relative to the organic polymerized material;
etching back the deposited etch selective material to reveal the protrusions;
etching back the protrusions to reveal the substrate; and
etching the substrate to form an inverse pattern of the patterned layer in the substrate at high fidelity.
2. The method of claim 1 wherein the etch selective material is selected from the group consisting of SiO 2 , Cr, Al 2 O 3 or Si.
3. The method of claim 1 wherein depositing the etch selective material further comprises a gap-fill deposition process.
4. The method of claim 1 further comprising etching back the residual layer prior to depositing the etch selective material.
5. The method of claim 1 wherein the depositing the etch selective material further comprises forming a conformal layer of the etch selective material over the patterned layer.
6. The method of claim 5 wherein further comprising completely filling in the recessions with the etch selective material.
7. The method of claim 6 wherein depositing the etch selective material further comprises a spin-on process.
8. The method of claim 5 further comprising forming a planarized layer of polymerized material over the conformal layer and then etching back the planarized layer to expose portions of the conformal layer.
9. The method of claim 1 wherein the recessions define a plurality of holes or wherein the protrusions define a plurality of parallel lines.
10. The method of claim 1 wherein the etch selective material is Al 2 O 3 .
11. An imprint lithography method comprising the steps of:
imprinting a patterned layer of an organic polymerized material on a substrate, the patterned layer having a residual layer and one or more protrusions and recessions defining features of the patterned layer, with the protrusions extending from the residual layer a height of 20 nm or less and having an aspect ratio of 1.5:1 to 3:1;
forming a conformal layer of etch selective material over the patterned layer and filling in the recessions of the patterned layer with the etch selective material, the etch selective material comprising a metal, metalloid or non-organic oxide having an etch selectivity of 50:1 or more relative to the organic polymerized material;
etching back the deposited etch selective material to reveal the protrusions;
etching back the protrusions to reveal the substrate; and
etching the substrate to form an inverse pattern of the patterned layer in the substrate at high fidelity.
12. The method of claim 11 wherein the etch selective material is selected from the group consisting of SiO 2 , Cr, Al 2 O 3 or Si.
13. The method of claim 11 wherein the etch selective material is SiO 2 and wherein the depositing further comprises a spin-on process.
14. The method of claim 11 wherein the recessions define a plurality of holes or wherein the protrusions define a plurality of parallel lines.
15. The method of claim 11 wherein the etch selective material is Al 2 O 3 .
16. An imprint lithography method comprising the steps of:
imprinting a patterned layer of an organic polymerized material on a substrate, the patterned layer having a residual layer and one or more protrusions and recessions defining features of the patterned layer, with the protrusions extending from the residual layer a height of 20 nm or less and having an aspect ratio of 1.5:1 to 3:1;
depositing an etch selective material solely on the protrusions of the patterned layer, the etch selective material comprising a metal, metalloid or non-organic oxide having an etch selectivity of 50:1 or more relative to the organic polymerized material;
etching back the residual layer to reveal the substrate; and
etching the substrate to form a corresponding pattern of the patterned layer in the substrate at high fidelity.
17. The method of claim 16 wherein the etch selective material is selected from the group consisting of SiO 2 , Cr, Al 2 O 3 or Si.
18. The method of claim 16 wherein the depositing the etch selective material further comprises a small-angle deposition process.
19. The method of claim 16 wherein the protrusions define a plurality of pillars or wherein the protrusions define a plurality of parallel lines.
20. The method of claim 16 wherein the etch selective material is Al 2 O 3 .