Hydrophobic surface coating with low wetting hysteresis, method for depositing same, microcomponent and use

• US 7,989,056 B2
• Filed: 07/01/2005
• Issued: 08/02/2011
• Est. Priority Date: 07/01/2005
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Original Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Inventors: Gaillard, Frédéric, Plissonnier, Marc, Fouillet, Yves
• Primary Examiner(s): Sample; David R.
• Assistant Examiner(s): Khan; Tahseen
• Application Number:
  US11/922,424
• Publication Number:
  US 20090142564A1
• Time in Patent Office: 2,223 Days
• Field of Search: 428/220, 106/287, 204/192.15, 427/569
• US Class Current: 428/220
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: C23C 16/36 Carbonitrides
• CPC Class Codes: G01N 33/5438 Electrodes
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding

Abstract

A hydrophobic surface coating, preferably obtained by chemical vapor deposition, comprises at least an upper thin layer formed by a compound selected from the group consisting of SiC_xO_y:H with x comprised between 1.4 and 2 and y comprised between 0.8 and 1.4 and SiC_x′N_y′:H with x′ comprised between 1.2 and 1.4 and y′ comprised between 0.6 and 0.8, so as to obtain a free surface with a low wetting hysteresis. Such a hydrophobic surface coating can be arranged on the free surface of a microcomponent comprising at least one substrate provided with, an electrode array and particularly suitable for moving drops of liquid by electrowetting on dielectric.

Claims

1. A hydrophobic surface coating comprising at least an uppermost thin layer formed by SiC_xO_y:

H, with x between 1.4 and 2 and y comprised between 0.8 and 1.4, so as to obtain a free surface with a low wetting hysteresis.

2. The surface coating according to claim 1, wherein the uppermost thin layer has a thickness less than or equal to 1 micrometer.

3. The surface coating according to claim 1, wherein the surface coating comprises a dielectric bottom thin layer.

4. The surface coating according to claim 3, wherein the bottom thin layer has a thickness less than or equal to 5 micrometers.

5. The surface coating according to claim 3, wherein the bottom thin layer has a relative dielectric constant greater than or equal to 2.

6. The surface coating according to claim 3, wherein the bottom thin layer is formed by a compound selected from the group consisting of SiO₂, SiN, SiCN, Ta₂O₅, TiO₂, HfO₂, ZrO₂, Al₂O₃, SrTiO₃, BaTiO₃ and Pb(ZrTi)O₃.

7. A microcomponent comprising at least a substrate provided with an electrode array and having a surface on which is arranged a surface coating according to claim 1, in such a way that the free surface of the surface coating is designed to receive at least a drop of liquid.

8. The microcomponent according to claim 7, wherein a voltage is successively applied to different electrodes of the electrode array so as to move the drop arranged on the free surface of the coating.

9. A method for depositing a surface coating according to claim 1 on a surface of a microcomponent, consisting at least in performing chemical vapor deposition, by means of a precursor selected among organosilanes, on the surface of said microcomponent to form an uppermost thin layer formed by SiC_xO_y:

H with x between 1.4 and 2 and y between 0.8 and 1.4 .

10. The method for depositing according to claim 9, wherein the chemical vapor deposition is plasma enhanced chemical vapor deposition.

11. The method for depositing according to claim 10, wherein the plasma enhanced chemical vapor deposition is performed in pulsed mode.

12. The method for depositing according to claim 9, wherein the upper thin layer being made of SiC_xO_y:

H, the precursor is formed by octamethylcyclotetrasiloxane and mixed with helium.

13. The method for depositing according to claim 9, consisting in depositing a bottom dielectric thin layer on the surface of said microcomponent, before forming the upper thin layer, by plasma enhanced chemical vapor deposition or by magnetron sputtering.

25. A microcomponent comprising at least a substrate provided with an electrode array and having a surface on which is arranged a surface coating according to claim 1, in such a way that the free surface of the surface coating is designed to receive at least a drop of liquid.

26. The microcomponent according to claim 25, wherein a voltage is successively applied to different electrodes of the electrode array so as to move the drop arranged on the free surface of the coating.

14. A hydrophobic surface coating comprising at least an uppermost thin layer formed by SiC_x′

N_y′

;

H, with x′

between 1.2 and 1.4 and y′

comprised between 0.6 and 0.8, so as to obtain a free surface with a low wetting hysteresis.

15. The surface coating according to claim 14, wherein the uppermost thin layer has a thickness less than or equal to 1 micrometer.

16. The surface coating according to claim 14, wherein the surface coating comprises a dielectric bottom thin layer.

17. The surface coating according to claim 16, wherein the bottom thin layer has a thickness less than or equal to 5 micrometers.

18. The surface coating according to claim 16, wherein the bottom thin layer has a relative dielectric constant greater than or equal to 2.

19. The surface coating according to claim 16, wherein the bottom thin layer is formed by a compound selected from the group consisting of SiO₂, SiN, SiCN, Ta₂O₅, TiO₂, HfO₂, ZrO₂, Al₂O₃, SrTiO₃, BaTiO₃ and Pb(ZrTi)O₃.

20. A method for depositing a surface coating according to claim 14 on a surface of a microcomponent, consisting at least in performing chemical vapor deposition, by means of a precursor selected among organosilanes, on the surface of said microcomponent to form an upper thin layer formed by SiC_x′

N_y′

;

H, with x′

between 1.2 and 1.4 and y′

between 0.6 and 0.8.

21. The method for depositing according to claim 20, wherein the chemical vapor deposition is plasma enhanced chemical vapor deposition.

22. The method for depositing according to claim 21, wherein the plasma enhanced chemical vapor deposition is performed in pulsed mode.

23. The method for depositing according to claim 20, wherein the upper thin layer being made of SiC_x′

N_y′

;

H, the precursor is formed by tetramethylsilane and mixed with nitrogen.

24. The method for depositing according to claim 20, consisting in depositing a bottom dielectric thin layer on the surface of said microcomponent, before forming the upper thin layer, by plasma enhanced chemical vapor deposition or by magnetron sputtering.