Method of fabricating patterned functional substrates
Methods of preparing organosilane-functionalized regions on a substrate surface and more specifically fabricating patterned functionalized substrates suitable to be optically read, the methods generally comprising employing a vapor deposition process of an organosilane gas onto a lithographically patterned silicon surface followed by removal of the patterning media in a bath of organic solvents and ultrasonic excitation. The inventive methods provide optimized surface density of functional species while avoiding deleterious effects that can occur when lithographically patterned substrates are exposed to various gaseous species during the functionalization process.
1. A method of functionalizing regions of a substrate with an organosilane, wherein the substrate comprises an organic layer and patterned regions of exposed substrate, comprising:
exposing the substrate to an organosilane vapor at a pressure below a pressure that causes the organic layer to reflow; and using at least a minimum dose of the organosilane vapor sufficient to provide a useful density of functional groups on the patterned regions; wherein,
the patterned regions have dimensions less than 1 μm; and
the minimum dose is at least 1×10 24 molecules per m 2 .
2. The method of claim 1 , wherein the organic layer comprises a resist material.
3. The method of claim 1 , wherein the organosilane comprises an aminosilane and the organosilane-functionalized regions comprise aminosilane functional groups.
4. The method of claim 3 , wherein the organosilane vapor is selected from aminopropyltrimethoxysilane. aminopropyltriethoxysilane, and a combination thereof.
5. The method of claim 1 , wherein the pressure is less than 200 mT.
6. The method of claim 1 , wherein the minimum deposition dose is at least 1×10 25 molecules per m 2 .
7. A method of preparing organosilane-functionalized regions, comprising:
providing a substrate having a surface;
depositing a resist on the surface;
developing selected regions of the resist;
etching the developed selected regions of the resist to expose selected regions of the substrate; and
depositing a first organosilane onto the exposed regions to provide organosilane-functionalized regions,
wherein the depositing is performed using an organosilane vapor at a pressure below a pressure that causes the organic layer to reflow; and using at least a minimum dose of the organosilane vapor sufficient to provide a useful density of functional groups on the patterned regions; wherein,
the patterned regions have dimensions less than 1 μm; and
the minimum dose is at least 1×10 24 molecules per m 2 .
8. The method of claim 7 , comprising, before the step of depositing a resist on the surface, depositing a second organosilane on the substrate surface to provide an organosilane-functionalized film on the substrate surface; and depositing a resist comprises depositing a resist on the organosilane-functionalized film.
9. The method of claim 8 , wherein the organosilane-functionalized film comprises terminal methyl groups.
10. The method of claim 7 , wherein the first organosilane comprises an aminosilane.
11. The method of claim 10 , wherein the aminosilane is selected from aminopropyltrimethoxysilane, aminopropyltriethoxysilane, and a combination thereof.
12. The method of claim 7 , wherein the organosilane-functionalized regions comprise a functionalized monolayer.
13. The method of claim 7 , wherein the organosilane vapor comprises aminopropyltrimethoxysilane and the pressure is less than 200 mT.
14. The method of claim 7 , wherein the organosilane vapor comprises aminopropyltrimethoxysilane and the minimum deposition dose is at least 1×10 25 molecules per m 2 .
15. The method of claim 7 , comprising stabilizing the organosilane-functionalized regions.
16. The method of claim 7 , comprising stripping the resist in a non-oxidizing solvent with ultrasonic excitation.
17. The method of claim 7 , wherein stripping the resist comprises moving or rotating the substrate.
18. A method of preparing functionalized regions, comprising:
providing a silicon substrate having a surface;
oxidizing the surface of the silicon substrate to provide an oxidized silicon surface;
functionalizing the oxidized silicon surface with a monolayer of terminal methyl groups;
depositing a resist on the methyl-functionalized surface;
developing selected regions of the resist, wherein the selected regions have dimensions less than 1 μm;
etching the developed selected regions of the resist to expose selected regions of the substrate; and
exposing the selected regions to an aminosilane vapor to provide a monolayer having terminal amine groups, wherein the aminosilane vapor has a pressure less than a pressure that causes the organic layer to reflow, and the exposing uses at least a minimum dose of the organosilane vapor sufficient to provide a useful density of terminal amine groups on the selected regions, wherein the minimum deposition dose is at least 1×10 24 molecules per m 2 ;
stabilizing the monolayer having terminal amine groups; and
exposing the resist to a non-oxidizing solvent with ultrasonic excitation to strip the resist.
19. The method of claim 18 , wherein the pressure is less than 200 mT.