Dielectric interference filter system, LCD-display and CCD-arrangement as well as process for manufacturing a dielectric interference filter system and use of this process

• US 6,342,970 B1
• Filed: 01/28/1997
• Issued: 01/29/2002
• Est. Priority Date: 03/03/1994
• Status: Expired due to Fees

• Current Assignee: Oerlikon Trading AG, Trubbach
• Original Assignee: Unaxis Balzers AG (Oerlikon USA, Inc. (Florida))
• Inventors: Rudigier, Helmut, Schoech, Helmut, Wierer, Peter, Sperger, Reinhard
• Primary Examiner(s): Spyrou, Cassandra
• Assistant Examiner(s): Juba, Jr., John
• Application Number:
  US08/789,581
• Time in Patent Office: 1,827 Days
• Field of Search: 359/587, 359/589, 359/590, 359/900, 359/580, 359/586, 349/80, 349/97, 349/104, 349/105, 349/106, 349/108, 349/110, 348/272, 348/273, 348/277, 348/280
• US Class Current: 359/587
• CPC Class Codes: G02B 5/003 Light absorbing elements
• CPC Class Codes: G02B 5/201 in the form of arrays
• CPC Class Codes: G02B 5/285 comprising deposited thin solid films G02B5/281 - G02B5/289 take precedence; multilayered film filters for fibre optic multiplexing G02B6/29361
• CPC Class Codes: G02F 1/133516 Methods for their manufacture, e.g. printing, electro-deposition or photolithography
• CPC Class Codes: G02F 1/133521 Interference filters
• CPC Class Codes: Y10S 359/90 Methods

Abstract

A dielectric interference filter system with at least filter elements of different spectral characteristics on the same carrier substrate is provided. The filter elements have the same height and/or adjoin each other without gaps. The system is used for, inter alia, interference color filter systems in the form of an LCD-display or CCD-arrangement. A process for manufacturing the system includes preparing at least one filter element by coating and subsequent etching, and preparing at least one subsequent filter element by coating and subsequent structuring utilizing lift-off in which the etching mask is used as the lift-off mask.

Claims

1. Dielectric interference filter system comprising at least two filter elements on a common carrier, each of the filter elements with a multitude of interference layers and spectrally different operational characteristics, the filter elements being laterally distinct from each other, wherein overall thicknesses of interference layers on each of the at least two filter elements differ by no more than 1% of the overall thickness of interference layers on each of the other of said at least two filter elements.

2. The system according to claim 1, wherein the at least two filter elements abut one another laterally.

3. The system according to claim 1, wherein the at least two filter elements are covered by a common interfering layer system configured to be transparent at least in operational spectral regions of the filter elements.

4. The system according to claim 3, wherein the common layer system comprises at least one electrically conductive ITO-layer.

5. The system according to claim 4, wherein the at least two filter elements abut one another laterally.

6. The system according to claim 1, wherein at least one black matrix element is operatively arranged at an at least one location in relation to the filter elements.

7. The system according to claim 6, wherein the at least two filter elements abut one another laterally.

8. The system according to claim 7, wherein the at least two filter elements are covered by a common interfering layer system configured to be transparent at least in operational spectral regions of the filter elements.

9. The system according to claim 1, wherein at least one first filter element is configured by coating, and by a subsequent etching, at least one second filter element is configured by coating, and a subsequent lift-off, and an etching mask for the at least one filter element is used as a lift-off mask for preparing the at least one second filter element.

10. The system according to claim 9, wherein the coating used to configure the at least one first filter element is one of a reactive or non-reactive PVD process and a CVD or PECVD process, and the etching is one of a reactive etching and a non-reactive AC,DC-, AC-plasma, DC-plasma etching.

11. The system according to claim 10, wherein the coating used to configure the at least one second filter element is the same as the first-mentioned coating.

12. The system according to claim 11, wherein the etching mask is one of a metal and lacquer.

13. The system according to claim 12, wherein the metal is one of Al and Cr.

14. The system according to claim 1, wherein the system constitutes a dielectric color filter system.

15. The system according to claim 1, wherein the filter elements comprise layers of at least two of the materials selected from the group consisting of (a) oxides or oxynitrides of Si, Hf, Ti, Zr , Ta, Nb, Al and (b) MgF₂ZnS, Si₃N₄.

16. LCD-display including a color filter system incorporating a dielectric interference filter system, comprising at least two filter elements with spectrally different operational characteristics on a common carrier, each of the filter elements being laterally distinct from each other, wherein overall thicknesses of interference layers on each of the at least two filter elements differ by no more than 1% of the overall thickness of interference layers on each of the other of said at least two filter elements.

17. CCD-arrangement including a color filter system incorporating a dielectric interference filter system comprising at least two filter elements with spectrally different operational characteristics on a common carrier, each of the at least two filter elements being laterally distinct from each other, wherein overall thicknesses of interference layers on each of the at least two filter elements differ by no more than 1% of the overall thickness of interference layers on each of the other of said at least two filter elements.

18. A method of manufacturing an interference color filter system having at least three filter elements on a common carrier, comprising:

preparing a first multilayer interference color filter layer by coating said common carrier;

applying a first etching mask on said first interference color filter layer;

plasma etching said first multilayer interference color filter layer with said first etching mask, thereby obtaining first interference color filter elements covered with said first etching mask and first uncovered areas of said carrier;

preparing a second multilayer interference color filter layer by coating upon said first etching mask and said first uncovered areas of said carrier;

applying a second etching mask upon said second multilayer interference color filter layer;

plasma-etching said second multilayer interference color filter layer with said second etching mask, thereby obtaining second interference color filter elements covered with said second etching mask and second uncovered areas of said carrier;

preparing a third multilayer interference color filter layer upon said second etching mask and said second uncovered areas; and

lifting off said first and second etching masks, thereby lifting off said third multilayer interference color filter layer.

19. The method according to claim 18, wherein the coating of the first interference color filter element is effected by one of a PVD, CVD and PECVD process.

20. The method according to claim 19, wherein the etching is effected by one of AC, DC or AC/DC plasma etching and reactive and non-reactive etching.

21. The method according to claim 20, wherein the etching mask is one of Al or Cr metal and lacquer.

22. The method according to claim 18, wherein more than one different interference color filter element is prepared successively by coating and etching, and the last interference color filter element is prepared by a lift-off technique.

23. A method of manufacturing an interference color filter system with more than two filter elements on a common carrier, comprising (a) preparing all the filter elements by masking and plasma etching, and (b) removing more than one etching mask and interference layers deposited thereupon in a common liftoff step.