Radiation based patterning methods
Stabilized precursor solutions can be used to form radiation inorganic coating materials. The precursor solutions generally comprise metal suboxide cations, peroxide-based ligands and polyatomic anions. Design of the precursor solutions can be performed to achieve a high level of stability of the precursor solutions. The resulting coating materials can be designed for patterning with a selected radiation, such as ultraviolet light, x-ray radiation or electron beam radiation. The radiation patterned coating material can have a high contrast with respect to material properties, such that development of a latent image can be successful to form lines with very low line-width roughness and adjacent structures with a very small pitch.
1. A method for forming a patterned substrate, the method comprising:
irradiating along a first pattern, a layer of a first coating material on the surface of a substrate, the layer having an average thickness from about 5 nm to about 30 nm, with EUV radiation at a dose of no more than about 100 mJ/cm 2 to form a patterned coating material having irradiated coating material and un-irradiated coating material according to the first pattern;
developing the patterned coating material to remove the un-irradiated coating material to form a developed patterned coating material; and
performing an ion etch to transfer the first pattern into the substrate to form the patterned substrate.
2. The method of claim 1 wherein the first coating material prior to irradiation comprises metal ions with radiation sensitive ligands and wherein interaction of the first coating material with EUV alters the chemical properties of the first coating material creating a structure with differential dissolution rates.
3. The method of claim 2 wherein the metal of the metal ions comprises Cu, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W, Ir, Pt, La, Ce, Pr, Nb, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or a combination thereof.
4. The method of claim 2 wherein the metal of the metal ions comprises Sn.
5. The method of claim 2 wherein the first coating material prior to irradiation comprises a blend of metal ions.
6. The method of claim 1 wherein the first coating material comprises an oxo/hydroxo network.
7. The method of claim 1 wherein the substrate comprises a silicon wafer, a silica substrate, a polymer substrate, composites thereof and combinations thereof.
8. The method of claim 1 wherein the irradiation is performed with EUV at a dose of from about 1 mJ/cm 2 to about 50 mJ/cm 2 .
9. The method of claim 1 wherein the first pattern has a pitch of no more than about 40 nm.
10. The method of claim 1 wherein developing is performed with a reactive gas or a liquid solution.
11. The method of claim 1 wherein developing is performed with a quaternary ammonium hydroxide.
12. The method of claim 1 wherein the patterned coating material comprises a metal oxide.
13. The method of claim 1 wherein the developed patterned coating material comprises openings to the substrate.
14. The method of claim 13 wherein the openings have an average width of no more than about 30 nm and/or an average line-width roughness of no more than about 2.25 nm.
15. The method of claim 1 wherein the patterned substrate comprises silicon nanopillars.
16. The method of claim 13 further comprising depositing material through the openings to the substrate.
17. The method of claim 1 further comprising removing the irradiated coating material after performing an ion etch.
18. The method of claim 17 wherein removing the irradiated coating material comprises an additional etching process, wherein the additional etching process comprises dry etching or wet etching.
19. The method of claim 1 further comprising heating the substrate with the developed patterned coating material to a temperature from about 150° C. to about 600° C. for from one minute to 25 minutes to form a post-patterning condensed structure.
20. The method of claim 19 further comprising prior to performing an ion etch:
depositing a layer of a second coating material over the post-patterning condensed structure;
irradiating the second coating material over the post-patterning condensed structure according to a second pattern; and
developing the second pattern to form a double patterned structure,
wherein performing an ion etch comprises etching the substrate according to a pattern formed by the first pattern and the second pattern.