Method for fabricating color filter using surface plasmon and method for fabricating liquid crystal display device

• US 7,989,254 B2
• Filed: 11/08/2010
• Issued: 08/02/2011
• Est. Priority Date: 12/18/2009
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Yoon, Min-Sung
• Primary Examiner(s): Le; Thao P.
• Application Number:
  US12/941,853
• Publication Number:
  US 20110151605A1
• Time in Patent Office: 267 Days
• Field of Search: 438/70, 257/59, 257/E31.121
• US Class Current: 438/70
• CPC Class Codes: G02B 5/008 Surface plasmon devices diffractive gratings with a pitch less than or comparable to the wavelength G02B5/1809; surface plasmons in integrated optics G02B6/1226; optical analysis of materials by means of surface plasmons G01N21/553
• CPC Class Codes: G02B 5/201 in the form of arrays
• CPC Class Codes: G02B 5/26 Reflecting filters G02B5/28 takes precedence
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 2202/36 Micro- or nanomaterials
• CPC Class Codes: G02F 2203/055 wavelength filtering
• CPC Class Codes: G02F 2203/10 plasmon
• CPC Class Codes: H01L 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask

Abstract

Discussed are methods for fabricating a color filter using a surface plasmon and a liquid crystal display (LCD) device capable of enhancing a transmittance ratio of an LC panel and simplifying entire processes, by forming a transmissive pattern consisting of a plurality of sub-wavelength holes having a period on a metal layer, and by implementing colors by selectively transmitting light of specific wavelengths with using a surface plasmon phenomenon.

Claims

1. A method for fabricating a color filter using a surface plasmon, the method comprising:

forming a metallic film formed of a conductive material on a substrate;

forming, on the metallic film, a dielectric layer formed of a dielectric material having a refractive index equal to or similar to that of the substrate;

forming a predetermined photosensitive pattern on the substrate having the dielectric layer formed thereon;

forming, below the predetermined photosensitive pattern, a dielectric pattern formed of the dielectric material, by selectively removing the dielectric layer by using the photosensitive pattern as a mask;

forming, in a metal layer formed of the metallic film, a transmissive pattern consisting of a plurality of sub-wavelength holes having a period, by selectively removing the metal layer by using the photosensitive pattern as a mask; and

forming, on the metal layer including the transmissive pattern, an insulating layer formed of the same material as the dielectric material.

2. The method of claim 1, wherein the dielectric layer is formed in a thickness of 5 nm˜

1000 nm.

3. The method of claim 1, wherein the metallic film is formed of a conductive material including at least one selected from a group consisting of aluminum, gold (Au), silver (Ag), platinum (Pt), copper (Cu), nickel (Ni), palladium (Pd), zinc (Zn), iron (Fe), chrome (Cr), molybdenum (Mo), a doped semiconductor device, carbon nanotube, fullerene, conductive plastic, and electrical conductive composite material, or a mixture thereof.

4. The method of claim 1, wherein the dielectric layer is formed of silicon oxide (SiO₂) in case of using a glass substrate as the substrate.

5. The method of claim 1, wherein the photosensitive pattern is formed by using one of a direct beam writing lithography, an ion beam milling, a nanosphere lithography, a nano imprinting, a photolithography, and a laser interference lithography.

6. The method of claim 1, wherein the dielectric layer is etched by a reactive ion etching (RIE) method based on CHF₃.

7. The method of claim 1, wherein the metallic film is etched by a reactive ion etching method based on Cl₂.

8. The method of claim 1, wherein the hole of the transmissive pattern is formed in a sub-wavelength size having a predetermined period, and has various shapes including a circular shape, an oval shape, a quadrangular shape, a triangular shape, and a slit shape.

9. The method of claim 1, wherein the insulating layer is formed to have a thickness of 10 nm˜

1000 nm.

10. The method of claim 1, wherein the insulating layer is formed by using one of a gas phase method, a liquid phase method, a solid phase method, and a nanosol coating method.

11. A method for fabricating a liquid crystal display (LCD) device, the method comprising:

providing a first substrate and a second substrate;

forming a metallic film formed of a conductive material on the first substrate;

forming, on the metallic film, a dielectric layer formed of a dielectric material having a refractive index equal to or similar to that of the first substrate;

forming a predetermined photosensitive pattern on the first substrate having the dielectric layer formed thereon;

forming, below the predetermined photosensitive pattern, a dielectric pattern formed of the dielectric material, by selectively removing the dielectric layer by using the photosensitive pattern as a mask;

forming, in a metal layer formed of the metallic film, a transmissive pattern consisting of a plurality of sub-wavelength holes having a period, by selectively removing the metal layer by using the photosensitive pattern as a mask;

forming, on the metal layer including the transmissive pattern, an insulating layer formed of the same material as the dielectric material;

forming a thin film transistor on the insulating layer; and

bonding the first and second substrates to each other,

wherein the second substrate has no color filter and black matrix formed thereon.

14. The method of claim 11, further comprising forming a common electrode or a back ITO electrode on the second substrate.

15. The method of claim 11, wherein the color filter is formed to have a 3D pattern structure having a transmissive pattern consisting of a plurality of holes of different sizes, and capable of selectively transmitting light of only red, green and blue wavelengths.

16. The method of claim 11, wherein the dielectric layer is formed to have a thickness of 5 nm˜

1000 nm.

17. The method of claim 11, wherein the metallic film is formed of a conductive material including at least one selected from a group consisting of aluminum, gold, silver, platinum, copper, nickel, palladium, zinc, iron, chrome, molybdenum, a doped semiconductor device, carbon nanotube, fullerene, conductive plastic, and electrical conductive composite material, or a mixture thereof.

18. The method of claim 11, wherein the dielectric layer is formed of silicon oxide (SiO₂) in case of using a glass substrate as the substrate.

19. The method of claim 11, wherein the photosensitive pattern is formed by using one of an e-beam lithography, an ion beam milling, a nanosphere lithography, a nano imprinting, a photolithography, and a laser interference lithography.

20. The method of claim 11, wherein the dielectric layer is etched by a reactive ion etching method based on CHF₃.

21. The method of claim 11, wherein the metallic film is etched by a reactive ion etching method based on Cl₂.

22. The method of claim 11, wherein the hole of the transmissive pattern is formed in a sub-wavelength size having a predetermined period, and has various shapes including a circular shape, an oval shape, a quadrangular shape, a triangular shape, and a slit shape.

23. The method of claim 11, wherein the insulating layer is formed to have a thickness of 10 nm˜

1000 nm.

24. The method of claim 11, wherein the insulating layer is formed by using one of a gas phase method, a liquid phase method, a solid phase method, and a nanosol coating method.

25. The method of claim 11, wherein the insulating layer serves as an over coating layer.

12. A method for fabricating a liquid crystal display (LCD) device, the method comprising:

providing a first substrate and a second substrate;

forming a metallic film formed of a conductive material on an external surface of the first substrate;

forming, on the metallic film, a dielectric layer formed of a dielectric material having a refractive index equal to or similar to that of the first substrate;

forming a predetermined photosensitive pattern on the first substrate having the dielectric layer formed thereon;

forming, below the predetermined photosensitive pattern, a dielectric pattern formed of the dielectric material, by selectively removing the dielectric layer by using the photosensitive pattern as a mask;

forming, in a metal layer formed of the metallic layer, a transmissive pattern consisting of a plurality of sub-wavelength holes having a period, by selectively removing the metal layer by using the photosensitive pattern as a mask;

forming, on the metal layer including the transmissive pattern, an insulating layer formed of the same material as the dielectric material;

forming a thin film transistor on an inner surface of the first substrate; and

bonding the first and second substrates to each other,

wherein the second substrate has no color filter and black matrix formed thereon.

13. A method for fabricating a liquid crystal display (LCD) device, the method comprising:

providing a first substrate and a second substrate;

forming a thin film transistor on the first substrate;

forming a metallic film formed of a conductive material on the second substrate;

forming, on the metallic film, a dielectric layer formed of a dielectric material having a refractive index equal to or similar to that of the second substrate;

forming a predetermined photosensitive pattern on the second substrate having the dielectric layer formed thereon;

forming, below the predetermined photosensitive pattern, a dielectric pattern formed of the dielectric material, by selectively removing the dielectric layer by using the photosensitive pattern as a mask;

forming, in a metal layer formed of the metallic film, a transmissive pattern consisting of a plurality of sub-wavelength holes having a period, by selectively removing the metal layer by using the photosensitive pattern as a mask;

forming, on the metal layer including the transmissive pattern, an insulating layer formed of the same material as the dielectric material; and

bonding the first and second substrates to each other.