Black mask, color filter and liquid crystal display

• US 6,285,424 B1
• Filed: 11/03/1998
• Issued: 09/04/2001
• Est. Priority Date: 11/07/1997
• Status: Expired due to Term

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Sumitomo Chemical Company Limited
• Inventors: Yoshida, Kazuaki
• Primary Examiner(s): TON, MINH TOAN T
• Application Number:
  US09/184,955
• Time in Patent Office: 1,036 Days
• Field of Search: 349/110, 349/111, 349/106, 349/137, 430/5, 430/7, 428/432, 204/192.28
• US Class Current: 349/110
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3626 one layer at least containing a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 17/3634 one layer at least containing carbon, a carbide or oxycarbide
• CPC Class Codes: C03C 17/3649 made of metals other than silver
• CPC Class Codes: C03C 17/3657 the multilayer coating having optical properties
• CPC Class Codes: C03C 2218/33 by etching
• CPC Class Codes: C03C 2218/34 Masking
• CPC Class Codes: C23C 14/00 Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
• CPC Class Codes: C23C 14/0036 Reactive sputtering
• CPC Class Codes: C23C 14/0635 Carbides
• CPC Class Codes: C23C 14/0641 Nitrides C23C14/0617 takes precedence
• CPC Class Codes: C23C 14/0676 Oxynitrides
• CPC Class Codes: C23C 14/08 Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/3492 Variation of parameters during sputtering
• CPC Class Codes: G02B 5/201 in the form of arrays
• CPC Class Codes: G02F 1/133502 Antiglare, refractive index matching layers
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence

Abstract

A black mask comprises: a first and a second antireflection films each comprising oxide, nitride, carbide, oxide nitride, oxide carbide, nitride carbide, or oxide nitride carbide of at least one kind of metal selected from the group consisting of chromium, molybdenum, tungsten, nickel, and germanium, and said films each having a different composition; and a screening film comprising at least one kind of metal selected from the group consisting of chromium, molybdenum, tungsten, nickel, and germanium; wherein said three films are successively formed on a transparent substrate, and at least one but not all of said three films contains chromium.

Having improved etching characteristics at the manufacturing process, low reflectivity in the whole visible wavelength range, and a small wavelength dependence of reflectivity, the black mask can be preferably used for a color filter and a liquid crystal display which can show clear pictures.

Claims

1. A black mask which comprises:

a first and a second antireflection films each comprising oxide, nitride, carbide, oxide nitride, oxide carbide, nitride carbide, or oxide nitride carbide of at least one kind of metal selected from the group consisting of chromium, molybdenum, tungsten, nickel, and germanium, and said films each having a different composition; and

a screening film comprising at least one kind of metal selected from the group consisting of chromium, molybdenum, tungsten, nickel, and germanium;

wherein said three films are successively formed on a transparent substrate, and at least one but not all of said three films contains chromium.

2. A black mask according to claim 1, wherein the first and the second antireflection films each comprise oxide, nitride, carbide, oxide nitride, oxide carbide, nitride carbide, or oxide nitride carbide of the same kind of metal.

3. A black mask according to claim 1, wherein the first and the second antireflection films each comprise oxide, nitride, carbide, oxide nitride, oxide carbide, nitride carbide, or oxide nitride carbide of different kind of metal.

4. A black mask according to claim 1, wherein both of the first and second antireflection film comprises tungsten compounds, and the screening film comprises chromium.

5. A black mask according to claim 1, wherein the first antireflection film comprises a chromium compound, the second antireflection film comprises a molybdenum compound or a tungsten compound, and the screening film comprises chromium.

6. A color filter which comprises:

the black mask described in claim 1, and colored resins disposed within a plurality of apertures of the black mask.

7. A liquid crystal display which comprises:

a first substrate comprising the color filter described in claim 6;

a second substrate comprising a plurality of electrodes;

a liquid crystal layer being interposed between the first and second substrates, and being capable of independently changing its orientation at different regions opposite to a plurality of the apertures of the black mask by applying a potential to said electrodes.