Patterned polymers and directed polymer growth by intiated chemical vapor deposition
A method of forming a patterned polymer layer on a substrate and a substrate having a polymer layer formed by the method. The method includes providing a substrate comprising a first surface having a first surface energy and a pattern located on the substrate forming a second surface having a second, lower surface energy than the first surface, and selectively depositing a polymeric layer onto the first surface using a monomer material in an initiated chemical vapor deposition process, wherein the initiated chemical vapor deposition process is operated under supersaturation conditions during the deposition process.
1. A method of forming a patterned polymer layer on a substrate comprising steps of:
providing a substrate comprising a first surface having a first surface energy and a pattern located on the substrate forming a second surface having a second, lower surface energy than the first surface;
selectively depositing a polymeric layer onto the first surface using a monomer material in an initiated chemical vapor deposition process carried out in a vacuum reactor kept at a constant pressure between about 0.1 Torr and about 100 Torr with the substrate held at a constant temperature in the range of about −15° C. to about 25° C., and the monomer is introduced to the depositing step at a flow rate between about 0.1 sccm and about 100 sccm, wherein the intitiated chemical vapor deposition process is operated under supersaturation conditions that result in a fractional saturation P m /P sat of the monomer in the range of greater than 1 to about 2 during the deposition process.
2. The method of claim 1 , wherein the first surface energy is at least 10% greater than the second surface energy.
3. The method of claim 1 , wherein the first surface energy is at least 10-400% greater than the second surface energy.
4. The method of claim 1 , wherein the first surface energy is at least 100% greater than the second surface energy.
5. The method of claim 1 , wherein the first surface energy is greater than about 1.5 J.m −2 .
6. The method of claim 5 , wherein the first surface energy is in the range of about 1.7 to about 2.4 J.m −2 .
7. The method of claim 1 , wherein the second, lower surface energy is lower than about 1.5 J.m −2 .
8. The method of claim 7 , wherein the second, lower surface energy is in the range of about 0.7 to about 1.3 J.m −2 .
9. The method of claim 1 , wherein the first surface comprises a material selected from the group consisting of, titanium, chromium, silicon, nickel, and platinum.
10. The method of claim 1 , wherein the first surface comprises silicon.
11. The method of claim 10 , wherein the second surface comprises silver, gold, or tin.
12. The method of claim 11 , wherein the polymer is selected from the group consisting of, poly(methyl methacrylate), poly(styrene), poly(vinylimidazole), and poly(vinylpyrrolidone).
13. The method of claim 1 , wherein the contact angle between the monomer and the first surface is lower than 10°.
14. The method of claim 13 , wherein the contact angle between the monomer and the second surface is higher than 10°.
15. The method of claim 1 , wherein the polymer is poly(vinylpyrrolidone).
16. The method of claim 1 , wherein the substrate is made by
placing a mask onto the first surface to define a pattern;
depositing the second material having the second surface energy onto the first surface containing the mask; and
removing the mask.
17. The method of claim 1 , wherein the fractional saturation P m /P sat of the monomer is about 1.2 to about 1.6.
18. A substrate comprising a patterned polymer layer formed by the method of claim 1 .