Pitch multiplication using self-assembling materials
View Patent ↗Self-assembling materials, such as block copolymers, are used as mandrels for pitch multiplication. The copolymers are deposited over a substrate and directed to self-assemble into a desired pattern. One of the blocks forming the block copolymers is selectively removed. The remaining blocks are used as mandrels for pitch multiplication. Spacer material is blanket deposited over the blocks. The spacer material is subjected to a spacer etch to form spacers on sidewalls of the mandrels. The mandrels are selectively removed to leave free-standing spacers. The spacers may be used as pitch-multiplied mask features to define a pattern in an underlying substrate.
1. A mask structure, comprising:
a first hardmask feature and a second hardmask feature extending lengthwise along a first direction over a surface of a substrate;
a first line between the first hardmask feature and the second hardmask feature, a second line disposed on a side of the first hardmask feature opposing the first line and a third line disposed on a side of the second hardmask feature opposing the first line, each of the first, second and third lines extending lengthwise along the first direction and comprising a first self-organized block copolymer material, each of the first line, the second line, the third line, the first hardmask feature and the second hardmask feature extending to equivalent elevations above the surface of the substrate;
extension material over the first hardmask feature, second hardmask feature and each of the first, second and third lines, the extension material comprising a second self-organized block copolymer material, the hardmask features and overlying extension material being patterned into first mandrels; the first, second and third lines and the overlying extension material being patterned into second mandrels;
etched sidewall spacers disposed on opposing sidewalls of each of the first and second mandrels, the etched sidewall spacers contacting the first self-organized block copolymer material and the extension material of the second mandrels and contacting the hardmask features and the extension material of the first mandrels; and
an open volume disposed between spacer material on opposing sidewalls of neighboring mandrels.
2. The mask structure of claim 1 , wherein the first self-organized block copolymer material comprises polystyrene.
3. The mask structure of claim 1 , wherein the first self-organized block copolymer material comprises polymethylmethacrylate.
4. The mask structure of claim 1 , wherein the first self-organized block copolymer material comprises cross-linked monomers.
5. The mask structure of claim 1 , wherein the substrate comprises a conductor.
6. The mask structure of claim 5 , wherein the conductor is a metal.
7. The mask structure of claim 1 , wherein an intermediate masking layer is disposed between the spacer material and the substrate.
8. The mask structure of claim 7 wherein the intermediate masking layer is an amorphous carbon layer.
9. The mask structure of claim 1 , wherein the substrate is a partially-formed integrated circuit.
10. The mask structure of claim 1 , wherein the substrate is a partially-formed grating structure.
11. The mask structure of claim 1 , wherein the substrate is a partially-formed disk drive device.
12. The mask structure of claim 1 , wherein the substrate is a partially-formed imprint reticle.