Topographically selective oxidation
View Patent ↗Methods for oxidizing organic compounds coated or adsorbed on a topographically patterned solid surface are provided. The methods can be used to selectively remove the organic compounds from the non-recessed areas.
1. A process for selectively removing adsorbed organic compositions from non-recessed areas of a topographically patterned substrate comprising recessed and non-recessed areas, comprising:
a. coating the topographically patterned substrate with a liquid hydrophilic solution comprising water and one or more solvents selected from the group consisting of alcohols, polyols, amines and polyamines so that the solution forms a flat surface over the substrate; and
b. exposing the surface of the liquid hydrophilic solution to ozone.
2. The process of claim 1 , wherein the liquid hydrophilic solution is coated onto the substrate by spin-coating.
3. The process of claim 1 , wherein the liquid hydrophilic solution has a viscosity greater than 10 centipoise.
4. A process for selectively removing adsorbed organic compositions from non-recessed areas of a topographically patterned substrate comprising recessed and non-recessed areas, comprising:
a. coating the topographically patterned substrate with a sufficient amount of a liquid hydrophilic solution to at least fill the recessed areas and to cover the non-recessed areas, wherein the solution has a viscosity greater than 10 centipoise;
b. providing a hydrophobic ozone diffuser comprising:
i. a vessel enclosing a volume that is at least partially filled with ozone gas, and
ii. an ozone-permeable membrane which forms a surface of the vessel,
wherein the membrane has an inner surface and an hydrophobic outer surface, and the inner surface is in contact with the ozone gas in the vessel; and
c. contacting the coated topographically patterned substrate with the outer surface of the ozone-permeable membrane of the diffuser in such a way as to form a layer of liquid hydrophilic solution less than 400 nm thick between the membrane and the non-recessed areas of the substrate; and
d. delivering ozone through the membrane to the non-recessed areas.
5. The process of claim 4 , wherein the liquid hydrophilic solution comprises tetramethylammonium hydroxide and at least one solvent selected from the group consisting of water, ethanol, and triethanolamine.
6. The process of claim 4 , wherein the liquid hydrophilic solution has a pH of greater than 6.5.
7. The process of claim 4 , wherein the ozone-permeable membrane comprises PTFE or a PTFE-coated membrane filter.
8. The process of claim 4 , wherein the organic composition is MPS.
9. The process of claim 4 , wherein the thickness of the layer of solution between the membrane and the non-recessed areas is less than 200 nm.
10. The process of claim 4 , wherein the diffuser is in dynamic contact with the coated substrate such that the diffuser moves across the surface of the substrate while maintaining a constant thickness of liquid layer between the non-recessed areas and the membrane.