SOLUTION PROCESSIBLE HARDMASKS FOR HIGH RESOLUTION LITHOGRAPHY

• US 20120223418A1
• Filed: 02/28/2012
• Published: 09/06/2012
• Est. Priority Date: 02/28/2011
• Status: Active Grant

• Current Assignee: Inpria Corporation (JSR Corporation)
• Original Assignee: Inpria Corporation (JSR Corporation)
• Inventors: Stowers, Jason K., Meyers, Stephen T., Kocsis, Michael, Keszler, Douglas A., Grenville, Andrew
• Granted Patent: US 9,281,207 B2
• Time in Patent Office: Days
• US Class Current: 257/632
• CPC Class Codes: C23C 18/06 Coating on selected surface areas, e.g. using masks
• CPC Class Codes: C23C 18/1216 Metal oxides C23C18/1212 takes precedence
• CPC Class Codes: G03F 7/091 characterised by antireflection means or light filtering or absorbing means, e.g. anti-halation, contrast enhancement
• CPC Class Codes: G03F 7/094 Multilayer resist systems, e.g. planarising layers
• CPC Class Codes: G03F 7/16 Coating processes; Apparatus therefor applying coatings to base materials in general B05; applying photosensitive compositions to base for photographic purposes G03C1/74
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• CPC Class Codes: H01L 21/02189 the material containing zirconium, e.g. ZrO2
• CPC Class Codes: H01L 21/02194 the material containing more than one metal element
• CPC Class Codes: H01L 21/02282 liquid deposition, e.g. spin-coating, sol-gel techniques, spray coating
• CPC Class Codes: H01L 21/0332 characterised by their composition, e.g. multilayer masks, materials
• CPC Class Codes: H01L 21/0338 Process specially adapted to improve the resolution of the mask
• CPC Class Codes: H01L 21/3081 characterised by their composition, e.g. multilayer masks, materials
• CPC Class Codes: H01L 21/3088 Process specially adapted to improve the resolution of the mask
• CPC Class Codes: H01L 21/31122 of layers not containing Si, e.g. PZT, Al2O3
• CPC Class Codes: H01L 21/31641 Deposition of Zirconium oxides, e.g. ZrO2

Abstract

Solution processible hardmasks are described that can be formed from aqueous precursor solutions comprising polyoxometal clusters and anions, such as polyatomic anions. The solution processible metal oxide layers are generally placed under relatively thin etch resist layers to provide desired etch contrast with underlying substrates and/or antireflective properties. In some embodiments, the metal oxide hardmasks can be used along with an additional hardmask and/or antireflective layers. The metal oxide hardmasks can be etched with wet or dry etching. Desirable processing improvements can be obtained with the solution processible hardmasks.

Claims

1. A method for forming a patterned structure by lithography on a layered structure that comprises a substrate, a hardmask composition and a radiation patternable resist layer on the hardmask layer, the method comprising:

applying an aqueous hardmask precursor composition comprising polyoxometal clusters and polyatomic inorganic anions on the substrate,

heating the hardmask precursor composition after application to the substrate to yield a metal oxide hardmask layer,

depositing the resist layer over the metal oxide hardmask layer,

exposing the layered structure to radiation to form an exposed structure with a latent image, and

developing the exposed structure to form a patterned resist layer exposing a pattern of the metal oxide layer corresponding with the latent image formed in the resist layer.

2. The method of claim 1 further comprising etching the metal oxide hardmask layer to form a patterned metal oxide layer that exposes a pattern of the substrate corresponding with the latent image formed in the resist layer.

3. The method of claim 2 wherein the etching of the metal oxide hardmask layer comprises reactive ion etching or treatment in aqueous acid or base.

4. The method of claim 2 further comprising etching the pattern of the substrate to form a patterned substrate corresponding with the latent image.

5. The method of claim 4 wherein the patterned substrate has a spacing between the centers of adjacent structures of no more than about 30 nm.

6. The method of claim 1 wherein the layered structure further comprises a spin-on carbon (SoC) hardmask, a vapor-deposited hardmask, a silicon-based anti-reflection layer (Si-ARC), or a combination thereof between the metal oxide hardmask layer and the substrate layer.

7. The method of claim 6 further comprising etching the metal oxide hardmask layer to form a patterned metal oxide layer and etching the spin-on-carbon (SoC) hardmask, the vapor-deposited hardmask, the silicon based anti-reflection layer (Si-ARC), or a combination thereof to pattern the layers and to expose a pattern of the substrate surface.

8. The method of claim 7 further comprising etching the substrate to form a patterned substrate corresponding with the latent image.

9. The method of claim 1 wherein the layered structure further comprises one or more hardmask layers and/or antireflective layers between the metal oxide hardmask layer and the resist layer.

10. The method of claim 1 wherein polyatomic anions of the applied hardmask precursor composition are partially or fully exchanged for hydroxide (OH⁻

) anions through ion exchange after deposition and prior to heat treatment.

11. The method of claim 1 wherein the resist comprises an organic polymer.

12. The method of claim 1 wherein the hardmask precursor layer is subjected to radiation curing prior to heating.

13. A layered structure comprising:

a substrate having a surface;

a hardmask composition comprising polyoxometal clusters and inorganic anions on the substrate surface having an average thickness from about 1 nm to about 50 nm; and

a radiation patternable resist layer on the metal oxide hardmask layer having an average thickness from about 10 nm to about 1 micron.

14. The layered structure of claim 13 wherein the substrate comprises a silicon wafer.

15. The layered structure of claim 13 wherein the hardmask composition comprises HfO_x(SO₄)_y.

16. The layered structure of claim 13 wherein the hardmask composition comprises AlO_x(PO₄)_y.

17. The layered structure of claim 13 wherein the hardmask composition comprises TiZrO_x(SO₄)_y.

18. The layered structure of claim 13 wherein the metal oxide layer comprises a mixture of HfO_x(SO₄)_y and AlO_x(PO₄)_y.

19. The layered structure of claim 13 wherein the metal oxide hardmask layer comprises Cr⁺⁶, Mo⁺⁶, W⁺⁶, V⁺⁵, Nb⁺⁵, Ta⁺⁵, P⁺⁵, Sb⁺⁵, Ti⁺⁴, Zr⁺⁴, Hf⁺⁴, Sn⁺⁴, Si⁺⁴, Ce⁺⁴, Ru⁺⁴, Sb⁺³, Y⁺³, Ga⁺³, Cr⁺³, Fe⁺³, Co³⁺, Ru³⁺, Al⁺³, In⁺³, Sc⁺³, Bi⁺³, La⁺³, Ce⁺³, Pr⁺³, Nd⁺³, Pm⁺³, Sm⁺³, Eu⁺³, Gd⁺³, Tb⁺³, Dy⁺³, Ho⁺³, Er⁺³, Tm⁺³, Yb⁺³, Lu⁺³, Zn⁺², Co²⁺, Ni²⁺, Mn⁺², Mg⁺², Ca⁺², Sr⁺², Ba⁺², or combinations thereof.

20. The layered structure of claim 13 wherein the resist layer comprises aliphatic copolymer structures, partially protected phenolic structures, hybrid aliphatic/phenolic structures, poly(hydroxystyrene), poly(methyl methacrylate) (PMMA), poly(methyl glutarimide) (PMGI), phenol formaldehyde resin, DNQ, epoxy resin, or a combination thereof.

21. The layered structure of claim 13 further comprising a 10 nm to about 1 micron thick spin-on-carbon (SOC) hardmask, vapor-deposited hardmask, silicon based anti-reflection layer (Si-ARC), or a combination thereof between the metal oxide layer and the substrate layer.

22. The layered structure of claim 13 further comprising one or more 10 nm to 1 micron thick hardmask layer(s) and/or an antireflective layer(s) between the metal oxide layer and the resist layer.

23. A method for forming a radiation patternable layered structure, the method comprising:

heating an aqueous metal oxide precursor solution on a deposition surface to form a solid metal oxide layer with an average thickness from about 1 nm to about 50 nm wherein the aqueous metal oxide precursor solution comprises polyoxometal clusters and inorganic anions; and

depositing a radiation patternable resist layer on the solid metal oxide layer to form the radiation patternable layered structure having a top resist layer with an average thickness from about 10 nm to about 1 micron.

24. The method of claim 23 further comprising treating the deposition surface with a pre-treatment agent to render the deposition surface hydrophilic.

25. The method of claim 24 wherein the pre-treatment agent is ultraviolet activated ozone.

26. The method of claim 23 wherein the deposition surface is a surface of a silicon wafer, a surface of a spin-on-carbon (SoC) hardmask, vapor-deposited hardmask, or a surface of a silicon based anti-reflection layer (Si-ARC).

27. The method of claim 23 further comprising applying the metal oxide precursor solution on the deposition surface with spin coating.

28. The method of claim 23 wherein the heating step comprising heating the metal oxide precursor at a temperature from about 50 to about 500 Celsius with no heating ramp.