ANTIREFLECTION FILM, METHOD FOR HEATING METAL FILM, AND HEATING APPARATUS

• US 20080024867A1
• Filed: 07/24/2007
• Published: 01/31/2008
• Est. Priority Date: 07/28/2006
• Status: Active Grant

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kubota, Shigeo, Kawashima, Toshitaka, Eguchi, Naoya, Ohsako, Junichi, Tatsuki, Koichi
• Granted Patent: US 8,693,099 B2
• Time in Patent Office: Days
• US Class Current: 359/586
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3621 one layer at least containing a fluoride
• CPC Class Codes: C03C 17/3628 one layer at least containing a sulfide
• CPC Class Codes: C03C 17/3649 made of metals other than silver
• CPC Class Codes: C03C 2217/734 comprising an alternation of high and low refractive indexes
• CPC Class Codes: G02B 1/115 Multilayers

Abstract

There is provided an antireflection film capable of reliably preventing light (or laser light), which is incident on a glass substrate and which reaches a metal film, from being reflected by the metal film. The antireflection film provided between a metal film having a complex refractive index represented by N_M=n_M−i·k_m and a glass substrate having a refractive index N_G includes, from the metal film side: (A) a first dielectric layer having a refractive index N₁; (B) a second dielectric layer provided on the first dielectric layer and having a refractive index N₂; and (C) a third dielectric layer provided on the second dielectric layer and having a refractive index N₃, in which N₁<n_M, N₁>N_G, N₂<N_G, and N₃>N_G hold. Accordingly, light which is incident on the glass substrate and which reaches the metal film is prevented from being reflected by the metal film.

Claims

1. An antireflection film provided between a metal film having a complex refractive index represented by N_M=n_M−

i·

k_m and a glass substrate having a refractive index N_G, comprising, from the metal film side;

(A) a first dielectric layer having a refractive index N₁;

(B) a second dielectric layer provided on the first dielectric layer and having a refractive index N₂; and

(C) a third dielectric layer provided on the second dielectric layer and having a refractive index N₃,

wherein N₁<

n_M, N₁>

N_G, N₂<

N_G, and N₃>

N_G hold, whereby light which is incident on the glass substrate and which reaches the metal film is prevented from being reflected by the metal film.

2. The antireflection film according to claim 1, wherein 1.51<

N₁<

3.53 holds.

3. The antireflection film according to claim 1, wherein, when the wavelength of the incident light is represented by λ

, an optical admittance Y₁ obtained when the first dielectric layer has a minimum thickness at which the reflectance of a laminated structure of the metal film and the first dielectric layer is minimized and an optical admittance Y₂ obtained from a laminated structure of the glass substrate, the third dielectric layer having an optical thickness of λ

/4, and the second dielectric layer having an optical thickness of λ

/4 satisfy the following equation

|Y₁−

Y₂|/α

≦

0.04

where α

≡

(n_M²+k_M²+N₁²)/(2×

n_M) holds.

4. The antireflection film according to claim 3, wherein the optical admittances Y₁ and Y₂ are represented by the following equations:

Y₁=α

−

{(n_M−

α

)²k_M²}^1/2 and Y₂=(N_G×

N₂²)/N₃², respectively.

5. The antireflection film according to claim 1, wherein the metal film includes molybdenum,

the second dielectric layer includes MgF₂,

n_M=3.53±

0.10, k_M=3.30±

0.10, N_G=1.51±

0.10, and N₂=1.38±

0.10 hold, and

4.29≦

N₁+N₃≦

4.40 holds.

6. The antireflection film according to claim 5, wherein the combination (between a material forming the first dielectric layer and a material forming the third dielectric layer) is (TiO₂, SiO_x), (Nb₂O₅, Ta₂O₅), (Nb₂O₅, ZrO₂), (CeO₂, Ta₂O₅), (CeO₂, ZrO₂), (Ta₂O₅, Nb₂O₅), (Ta₂O₅, CeO₂), (ZrO₂, Nb₂O₅), (ZrO₂, CeO₂), or (HfO₂, ZnS).

7. The antireflection film according to claim 1, wherein the metal film includes chromium,

the second dielectric layer includes MgF₂,

n_M=3.18±

0.10, k_M=4.41±

0.10, N_G=1.51±

0.10, and N₂=1.38±

0.10 hold, and

4.69≦

N₁+N₃≦

4.75 holds.

8. The antireflection film according to claim 7, wherein the combination (between a material forming the first dielectric layer and a material forming the third dielectric layer) is (TiO₂, ZnS) or (ZnS, TiO₂).

9. The antireflection film according to claim 1, wherein the metal film includes a nickel alloy,

the second dielectric layer includes MgF₂,

n_M=2.94±

0.10, k_M=2.92±

0.10, N_G=1.51±

0.10, and N₂=1.38±

0.10 hold, and

4.14≦

N₁+N₃≦

4.22 holds.

10. The antireflection film according to claim 9, wherein the combination (between a material forming the first dielectric layer and a material forming the third dielectric layer) is (TiO₂, Y₂O₃).

11. The antireflection film according to claim 1, wherein the metal film includes molybdenum,

the second dielectric layer includes SiO_x,

n_M=3.53±

0.10, k_M=3.30±

0.10, N_G=1.51±

0.10, and N₂=1.46±

0.10 hold, and

4.46≦

N₁+N₃≦

4.52 holds.

12. The antireflection film according to claim 11, wherein the combination (between a material forming the first dielectric layer and a material forming the third dielectric layer) is (Nb₂O₅, Nb₂O₅), (Nb₂O₅, CeO₂), (CeO₂, CeO₂), or (CeO₂, Nb₂O₅).

13. The antireflection film according to claim 1, wherein 7.08≦

n_M+N₁+N₃≦

8.28 holds.

14. The antireflection film according to claim 1, further comprising a second antireflection film on the surface of the glass substrate opposite to that on which the third dielectric layer is provided.

15. The antireflection film according to claim 14, wherein the glass substrate of a laminated structure composed of the second antireflection film, the glass substrate, the third dielectric layer, the second dielectric layer, the first dielectric layer, and the metal film has a curvature radius of 1.0×

10⁵ m or more.

16. A method for heating a metal film which forms a laminated structure together with an antireflection film and a glass substrate, the method comprising:

irradiating the metal film with laser light through the glass substrate and the antireflection film,

wherein the metal film has a complex refractive index represented by N_M=n_M−

i·

k_m,

the glass substrate has a refractive index N_G,

the antireflection film includes, from the metal film side,

(A) a first dielectric layer having a refractive index N₁;

(B) a second dielectric layer provided on the first dielectric layer and having a refractive index N₂; and

(C) a third dielectric layer provided on the second dielectric layer and having a refractive index N₃, and

N₁<

n_M, N₁>

N_G, N₂<

N_G, and N₃>

N_G hold.

17. A heating apparatus for heating a metal film which forms a laminated structure together with an antireflection film and a glass substrate by irradiating the metal film with laser light through the glass substrate and the antireflection film, the heating apparatus comprising:

(a) a laminated structure receiving stage for receiving the laminated structure with a gap provided therebetween so that the metal film faces downward;

(b) a laser light source; and

(c) a moving device for moving the laminated structure receiving stage relative to the laser light source,

wherein the metal film has a complex refractive index represented by N_M=n_M−

i·

k_m,

the glass substrate has a refractive index N_G,

the antireflection film includes, from the metal film side,

(A) a first dielectric layer having a refractive index N₁;

(B) a second dielectric layer provided on the first dielectric layer and having a refractive index N₂; and

(C) a third dielectric layer provided on the second dielectric layer and having a refractive index N₃, and

N₁<

n_M, N₁>

N_G, N₂<

N_G, and N₃>

N_G hold.