ITO-coated article for use with touch panel display assemblies, and/or method of making the same

• US 20100122900A1
• Filed: 11/18/2008
• Published: 05/20/2010
• Est. Priority Date: 11/18/2008
• Status: Active Grant

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Krasnov, Alexey
• Granted Patent: US 8,080,141 B2
• Time in Patent Office: Days
• US Class Current: 204/192.150
• CPC Class Codes: C03C 17/2456 Coating containing TiO2
• CPC Class Codes: C03C 2217/212 TiO2
• CPC Class Codes: C03C 2218/154 by sputtering
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: C23C 14/5806 Thermal treatment
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels

Abstract

Certain example embodiments of this invention relate to techniques for making a coated article including a transparent conductive indium-tin-oxide (ITO) film supported by a heat treated glass substrate. A substantially sub-oxidized ITO or metallic indium-tin (InSn) film is sputter-deposited onto a glass substrate at room temperature. The glass substrate with the as-deposited film thereon is subjected to elevated temperatures. Thermal tempering or heat strengthening causes the as-deposited film to be transformed into a crystalline transparent conductive ITO film. Advantageously, this may reduce the cost of touch panel assemblies, e.g., because of the higher rates of the ITO deposition in the metallic mode. The cost of touch-panel assemblies may be further reduced through the use of float glass.

Claims

1. A method of making a coated article, the method comprising:

providing a substantially transparent substrate;

sputtering a substantially sub-oxidized indium tin oxide (ITO) and/or metallic-mode indium-tin film, directly or indirectly, on the substrate via an indium-tin (InSn) target, said sputtering being performed at or close to room temperature; and

heat treating the substrate with the substantially sub-oxidized ITO and/or metallic-mode indium-tin film such that the layer of substantially sub-oxidized ITO and/or metallic-mode indium-tin film is transformed into a substantially transparent and electrically conductive crystalline resultant ITO film.

2. The method of claim 1, wherein the substrate is a reduced iron soda-lime float glass.

3. The method of claim 1, wherein following said sputtering, the substantially sub-oxidized indium tin oxide (ITO) and/or metallic-mode indium-tin film is either amorphous or partially crystalline.

4. The method of claim 1, wherein the InSn target has an In/Sn weight ratio is from 95/5 to 80/20.

5. The method of claim 1, wherein the resultant ITO film has a sheet resistance of less than about 70 ohms/square.

6. The method of claim 1, wherein the resultant ITO film has a sheet resistance of less than about 50 ohms/square.

7. The method of claim 1, wherein said heat treating is further practiced by thermally tempering the glass substrate with the amorphous or partially crystalline ITO film or InSn film at a temperature of at least about 600 degrees C.

8. The method of claim 1, wherein said heat treating is further practiced by heat strengthening the glass substrate with the amorphous or partially crystalline ITO film or InSn film at a temp of about 600 degrees C.

9. The method of claim 1, further comprising disposing a buffer layer between said substrate and said substantially sub-oxidized indium tin oxide (ITO) and/or metallic-mode indium-tin film.

10. The method of claim 9, wherein said buffer layer comprising a dielectric material.

11. The method of claim 1, further comprising disposing a layer comprising silicon nitride between said substrate and said substantially sub-oxidized indium tin oxide (ITO) and/or metallic-mode indium-tin film.

12. The method of claim 1, wherein the resultant ITO film has a visible transmission of at least about 70%.

13. The method of claim 1, wherein the resultant ITO film has a visible transmission of at least about 75%.

14. The method of claim 1, wherein said substantially sub-oxidized indium tin oxide (ITO) and/or metallic-mode indium-tin film comprises (InSn)_xO_y, wherein 0<

y<

0.5, and wherein x=1−

y.

15. The method of claim 1, wherein said substantially sub-oxidized indium tin oxide (ITO) and/or metallic-mode indium-tin film comprises (InSn)_xO_y, wherein 0.1<

y<

0.3, and wherein x=1−

y.

16. The method of claim 1, wherein said sputtering is performed in a substantially pure argon environment.

17. The method of claim 1, wherein said sputtering is performed in an environment having an oxygen-to-argon ratio of 0 to 0.4, more preferably 0 to 0.1.

18. A method of making a coated article, the method comprising:

providing a substantially transparent soda-lime float glass substrate;

sputtering an intermediate film, directly or indirectly, on the substrate via an indium-tin (InSn) target, said intermediate film comprising a substantially sub-oxidized indium tin oxide (ITO) and/or metallic-mode indium-tin film, said sputtering being performed at or close to room temperature; and

heat strengthening or thermally tempering the substrate together with the intermediate film to produce an electrically conductive and crystalline resultant ITO film,

wherein said intermediate film comprises (InSn)_xO_y, wherein 0<

y<

0.5, and wherein x=1−

y, and

wherein said sputtering is performed in an environment having an oxygen-to-argon ratio of 0 to 0.4, more preferably 0 to 0.1.

19. The method of claim 18, further comprising disposing a dielectric buffer layer between said substrate and said intermediate film.

20. The method of claim 19, wherein the resultant ITO film together with the dielectric buffer layer has a visible transmission of at least about 70%.

21. A method of making an electronic device, the method comprising:

providing a coated article comprising an ITO coating, the coated article having an intermediate film sputtered, directly or indirectly, on the substrate via an indium-tin (InSn) target, said intermediate film comprising a substantially sub-oxidized indium tin oxide (ITO) and/or metallic-mode indium-tin film, said sputtering being performed at or close to room temperature, the substrate and the intermediate film having been heat treated to produce an electrically conductive and crystalline resultant ITO film, wherein said intermediate film comprises (InSn)_xO_y, wherein 0<

y<

0.5, and wherein x=1−

y, and wherein said sputtering is performed in an environment having an oxygen-to-argon ratio of 0 to 0.4, more preferably 0 to 0.1.

22. The method of claim 22, further comprising incorporating the coated article into the electronic device.