Controlled vapor deposition of biocompatible coatings over surface-treated substrates

• US 20060088666A1
• Filed: 12/05/2005
• Published: 04/27/2006
• Est. Priority Date: 06/04/2004
• Status: Active Grant

• Current Assignee: SPTS Technologies Limited (KLA Corporation)
• Original Assignee: Applied Microstructures, Inc. (KLA Corporation)
• Inventors: Chinn, Jeffrey D., Nowak, Romuald, Kobrin, Boris
• Granted Patent: US 7,695,775 B2
• Time in Patent Office: Days
• US Class Current: 427/569
• CPC Class Codes: B05D 1/60 Deposition of organic layers from vapour phase vapour phase deposition in general C23C14/00, C23C16/00
• CPC Class Codes: B05D 3/064 involving also the use of a gas
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites

Abstract

We have developed an improved vapor-phase deposition method and apparatus for the application of layers and coatings on various substrates. The method and apparatus are useful in the fabrication of biofunctional devices, Bio-MEMS devices, and in the fabrication of microfluidic devices for biological applications. In one important embodiment, a siloxane substrate surface is treated using a combination of ozone and UV radiation to render the siloxane surface more hydrophilic, and subsequently a functional coating is applied in-situ over the treated surface of the siloxane substrate.

Claims

1. A method converting a surface of a siloxane substrate from a hydrophobic nature, where a water droplet contact angle is in a range of about 90 degrees to about 130 degrees, to a hydrophilic nature, where said water droplet contact angle ranges from about 5 degrees to about 50 degrees, wherein said surface of said siloxane substrate is treated with ozone in the presence of UV radiation.

2. A method in accordance with claim 1, wherein said UV radiation exhibits a wavelength ranging from about 172 nm to about 254 nm, and a UV flux density ranging from about 20 mW/cm² to about 1.0 W/cm².

3. A method in accordance with claim 2, wherein said UV flux density ranges from about 50 mW/cm² to about 0.2 W/cm².

4. A method in accordance with claim 2, wherein the treatment time period of said siloxane surface with a combination of ozone and UV radiation ranges from about 60 minutes to about 1 minute.

5. A method in accordance with claim 4, wherein said treatment is carried out at a temperature ranging from about 20°

C. to about 80°

C.

6. A method in accordance with claim 2, wherein said treatment is carried out at a pressure ranging from about 1 Torr to about atmospheric pressure.

7. A method in accordance with claim 1, wherein said siloxane is PDMS.

8. A method in accordance with claim 1 or claim 2, wherein said siloxane substrate is treated with ozone in the presence of UV radiation, followed by deposition of a PEG layer.

9. A method in accordance with claim 1 or claim 2, wherein said siloxane substrate is treated with ozone in the presence of UV radiation, followed by an oxygen plasma, followed by deposition of a PEG layer.

10. A method in accordance with claim 1 or claim 2, wherein a layer of PEG is applied over said siloxane substrate, where said siloxane substrate has been treated with a plasma which includes ozone in the presence of UV radiation.

11. A method in accordance with claim 10, wherein said plasma which includes ozone also includes oxygen.

12. A method in accordance with claim 8, wherein said layer of PEG is applied using a vapor deposition technique which includes a stagnation reaction step.

13. A method in accordance with claim 9, wherein said layer of PEG is applied using a vapor deposition technique which includes a stagnation reaction step.

14. A method in accordance with claim 10, wherein said layer of PEG is applied using a vapor deposition technique which includes a stagnation reaction step.

15. A method in accordance with claim 11, wherein said layer of PEG is applied using a vapor deposition technique which includes a stagnation reaction step.

16. A method in accordance with claim 1 or claim 2, wherein a biocompatible vapor-deposited coating is applied over said siloxane substrate treated with ozone in the presence of UV radiation, and where said biocompatible coating includes at least one organic functional layer.

17. A method in accordance with claim 1 or claim 2, wherein a biocompatible vapor-deposited coating is applied over said siloxane substrate treated with ozone in the presence of UV radiation, and where said biocompatible coating includes at least one oxide-based layer and at least one organic functional layer.

18. A method in accordance with claim 16, wherein said at least one organic functional layer includes a surface layer which is generated from a polyethylene glycol-comprising precursor.

19. A method in accordance with claim 17, wherein said at least one organic functional layer includes a surface layer which is generated from a polyethylene glycol-comprising precursor.

20. A method in accordance with claim 16, wherein said method comprises the steps of:

a) exposing said surface of said siloxane substrate to an ozone-comprising gas in a processing chamber, wherein UV radiation is applied during exposure of said siloxane surface to said ozone-comprising gas;

b) subsequently, without exposure of said ozone and UV radiation treated siloxane substrate to ambient conditions which contaminate or react with said treated surface, exposing said surface to a silicon chloride containing vapor in the presence of moisture, to form a hydrophilic silicon oxide layer on said treated siloxane substrate surface;

c) subsequently, without exposure of said hydrophilic silicon oxide layer to ambient conditions which contaminate or react with said hydrophilic silicon oxide layer, exposing said silicon oxide layer to a functionalized silane precursor vapor to form a layer selected from the group consisting of a monolayer, a self-aligned monolayer, and a polymerized cross-linked layer.

21. A method in accordance with claim 20, including an additional step:

d) repeating steps a) through c), or repeating steps b) through c), or repeating step c) a nominal number of times, without exposing said substrate to ambient conditions.

22. A method in accordance with claim 21, wherein said processing chamber pressure subatmospheric pressure during step a) ranges from about 1 Torr to about 1 atmosphere.

23. A method in accordance with claim 20, wherein said silicon chloride-containing precursor in step b) is silicon tetrachloride.

24. A method in accordance with claim 20, wherein said siloxane is PDMS.