Double self aligned via patterning
A method including forming a penta-layer hardmask above a substrate, the penta-layer hardmask comprising a first hardmask layer above a second hardmask layer; forming a trench pattern in the first hardmask layer; transferring a first via bar pattern from a first photo-resist layer above the penta-layer hardmask into the second hardmask layer resulting in a first via pattern, the first via pattern in the second hardmask layer overlapping the trench pattern and being self-aligned on two sides by the trench pattern in the first hardmask layer; and transferring the first via pattern from the second hardmask layer into the substrate resulting in a self-aligned via opening, the self-aligned via opening being self-aligned on all sides by the first via pattern in the second hardmask layer.
1. A method comprising:
forming a penta-layer hardmask above a substrate, the penta-layer hardmask comprising a first hardmask layer above a second hardmask layer;
forming a trench pattern in the first hardmask layer;
transferring a first via bar pattern from a first photo-resist layer above the penta-layer hardmask into the second hardmask layer resulting in a first via pattern, the first via pattern in the second hardmask layer overlapping the trench pattern and being self-aligned on two sides by the trench pattern in the first hardmask layer,
wherein the transferring the first via bar pattern from the first photo-resist layer includes forming a first anti reflective coating (ARC) layer above a first planarization layer above the penta-layer hardmask and forming the first via bar pattern in the first photo-resist layer on top of the first ARC layer; and
transferring the first via pattern from the second hardmask layer into the substrate resulting in a self-aligned via opening, the self-aligned via opening being self-aligned on all sides by the first via pattern in the second hardmask layer.
2. The method of claim 1 , further comprising:
transferring a second via bar pattern from a second photo-resist layer above the penta-layer hardmask into the second hardmask layer resulting in a second via pattern, the second via pattern in the second hardmask layer overlapping the trench pattern and being self-aligned on two sides by the trench pattern in the first hardmask layer; and
transferring the second via pattern, simultaneously with the first via pattern, from the second hardmask layer into the substrate resulting in a self-aligned via opening, the self-aligned via opening being self-aligned on all sides by the self-aligned via pattern in the second hardmask layer.
3. The method of claim 2 , wherein transferring the second via bar pattern from the second photo-resist layer above the penta-layer hardmask into the second hardmask layer resulting in the second via pattern comprises:
depositing a second anti-reflective coating (ARC) layer above a second planarization layer above the penta-layer hardmask;
forming the second via bar pattern in the second photo-resist material on top of the ARC layer;
transferring the second via bar pattern from the second photo-resist layer into the second ARC layer and the second planarization layer;
transferring the second via bar pattern from the second ARC layer and the second planarization layer into the second hardmask; and
removing the second block ARC layer and the second block planarization layer.
4. The method of claim 1 , wherein transferring the first via bar pattern from the first photo-resist layer above the penta-layer hardmask into the second hardmask layer resulting in the first via pattern comprises:
transferring the first via bar pattern from the first photo-resist layer into the first ARC layer and the first planarization layer;
transferring the first via bar pattern from the first ARC layer and the first planarization layer into the second hardmask; and
removing the first block ARC layer and the first block planarization layer.
5. The method of claim 1 , further comprising:
transferring the trench pattern into the substrate.
6. The method of claim 5 , wherein transferring the trench pattern into the substrate comprises:
transferring the trench pattern from the first hardmask layer into the second hardmask layer; and
transferring the trench pattern from the second hardmask layer into the substrate.
7. The method of claim 1 , wherein forming the penta-layer hardmask above the substrate comprises:
depositing a third patterning layer above the substrate;
depositing the second hardmask layer above the first patterning layer;
depositing a second patterning layer above the second hardmask layer;
depositing the first hardmask layer above the second patterning layer; and
depositing a first patterning layer above the first hardmask layer.
8. A method comprising:
forming a penta-layer hardmask above a substrate, the penta-layer hardmask comprising a first hardmask layer above a second hardmask layer;
forming a trench pattern in the first hardmask layer;
transferring a first via bar pattern from a first photo-resist layer above the penta-layer hardmask into the second hardmask layer resulting in a first via pattern, the first via pattern in the second hardmask layer overlapping the trench pattern and being self-aligned on two sides by the trench pattern in the first hardmask layer;
transferring a second via bar pattern from a second photo-resist layer above the penta-layer hardmask into the second hardmask layer resulting in a second via pattern, the second via pattern in the second hardmask layer overlapping the trench pattern and being self-aligned on two sides by the trench pattern in the first hardmask layer; and
transferring the first via pattern from the second hardmask layer into the substrate resulting in a self-aligned via opening, the self-aligned via opening being self-aligned on all sides by the first via pattern in the second hardmask layer.
9. The method of claim 1 , further comprising:
transferring the second via pattern, simultaneously with the first via pattern, from the second hardmask layer into the substrate resulting in a self-aligned via opening, the self-aligned via opening being self-aligned on all sides by the self-aligned via pattern in the second hardmask layer.
10. The method of claim 8 , wherein transferring the second via bar pattern from the second photo-resist layer above the penta-layer hardmask into the second hardmask layer resulting in the second via pattern comprises:
depositing a second anti-reflective coating (ARC) layer above a second planarization layer above the penta-layer hardmask;
forming the second via bar pattern in the second photo-resist material on top of the ARC layer;
transferring the second via bar pattern from the second photo-resist layer into the second ARC layer and the second planarization layer;
transferring the second via bar pattern from the second ARC layer and the second planarization layer into the second hardmask; and
removing the second block ARC layer and the second block planarization layer.
11. The method of claim 8 , wherein transferring the first via bar pattern from the first photo-resist layer above the penta-layer hardmask into the second hardmask layer resulting in the first via pattern comprises:
depositing a first anti-reflective coating (ARC) layer above a first planarization layer above the penta-layer hardmask;
forming the first via bar pattern in the first photo-resist material on top of the first ARC layer;
transferring the first via bar pattern from the first photo-resist layer into the first ARC layer and the first planarization layer;
transferring the first via bar pattern from the first ARC layer and the first planarization layer into the second hardmask; and
removing the first block ARC layer and the first block planarization layer.
12. The method of claim 1 , further comprising:
transferring the trench pattern into the substrate.
13. The method of claim 12 , wherein transferring the trench pattern into the substrate comprises:
transferring the trench pattern from the first hardmask layer into the second hardmask layer; and
transferring the trench pattern from the second hardmask layer into the substrate.
14. The method of claim 8 , wherein forming the penta-layer hardmask above the substrate comprises:
depositing a third patterning layer above the substrate;
depositing the second hardmask layer above the first patterning layer;
depositing a second patterning layer above the second hardmask layer;
depositing the first hardmask layer above the second patterning layer; and
depositing a first patterning layer above the first hardmask layer.