Method for etching conductive metal oxide layer using microelectrode

1. A method for etching a selected area of a conductive metal oxide layer deposited on a support, comprising removing said area via electrochemical route in the presence of a polarized microelectrode and an electrochemical solution,

wherein the electrochemical solution comprises at least one chemical compound comprising at least one —COOH group and an ethylene unsaturation.

2. The method according to claim 1 , wherein said conductive metal oxide is a transparent conductive oxide (TCO).

3. The method according to claim 1 , wherein said conductive metal oxide is selected from the group consisting of an optionally doped indium oxide, optionally doped tin oxide, optionally doped zinc oxide, optionally doped cadmium oxide, optionally doped gallium oxide, optionally doped thallium oxide, optionally doped lead oxide, optionally doped antimony oxide, optionally doped niobium oxide, optionally doped tungsten oxide, optionally doped zirconium oxide, optionally doped ruthenium oxide, optionally doped barium oxide, optionally doped selenium oxide, optionally doped bismuth oxide, and mixtures thereof.

4. The method according to claim 1 , wherein said conductive metal oxide is tin-doped indium oxide (ITO).

5. The method according to claim 1 , wherein said microelectrode is selected from the group consisting of an ultramicroelectrode (UME), a probe of a scanning electrochemical microscope (SECM) and a probe of an atomic force microscope in electrochemical mode (AFM-SECM).

6. The method according to claim 1 , wherein said removing comprises the following steps:

a) positioning said microelectrode close to the surface of the said selected area;

b) contacting said electrochemical solution with at least said selected area; and

c) polarizing said microelectrode,

the sequence of steps being either (a), (b) and (c), or (a), (c) and (b).

7. The method according to claim 1 , wherein said removing comprises the following steps:

a) positioning said microelectrode close to the surface of the said selected area;

b) contacting said electrochemical solution with at least said selected area; and

c) polarizing said microelectrode and said conductive metal oxide layer,

the sequence of steps being either (a), (b) and (c), or (a), (c) and (b).

8. The method according to claim 1 , wherein said electrochemical solution comprises a protic solvent.

9. The method according to claim 1 , wherein the conductive metal oxide layer being an ITO layer, the potential applied to the microelectrode is higher than 3 V.

10. The method according to claim 7 , wherein the conductive metal oxide layer being an ITO layer, the potential applied to the said ITO layer is higher than −1 V.

11. The method according to claim 1 , wherein it comprises an additional step to move the microelectrode close to the selected area of the conductive metal oxide layer.

12. The method according to claim 1 , wherein said support not only has a conductive metal oxide layer deposited on the support, but also at least one other layer of conductor, semiconductor or insulating material deposited on this conductive metal oxide layer.

13. A conductive metal oxide layer etched using the method defined in claim 7 .

14. The method according to claim 6 , wherein, in c), the microelectrode and the conductive metal oxide layer are polarized.

15. The method according to claim 1 , wherein said electrochemical solution comprises at least one element selected from the group consisting of acrylic acid, methacrylic acid, methyl methacrylic acid, ethacrylic acid, alpha-chloroacrylic acid, alpha-cyano acrylic acid, crotonic acid, alpha-phenyl acrylic acid, sorbic acid, alpha-chloro sorbic acid, angelic acid, cinnamic acid, p-chloro cinnamic acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, aconitic acid, fumaric acid, tricarboxy ethylene, oxalic acid, maleic acid, benzene tetracarboxylic acid, 1,2,3,4-butane tetracarboxylic acid and 1,2,3-propane tricarboxylic acid.

16. The method according to claim 8 , wherein said protic solvent is selected from the group consisting of water, deionized water, distilled water, acidified water, acidified deionized water and acidified distilled water.

17. The method according to claim 9 , the potential applied to the microelectrode is higher between 4 V to 10 V.

18. The method according to claim 9 , the potential applied to the microelectrode is the order of 7 V.

19. The method according to claim 10 , wherein the potential applied to the said ITO layer is between 0 V and −1 V.

20. The method according to claim 10 , wherein the potential applied to the said ITO layer is the order of −0.1 V.