Zinc-based film manipulation for an optical filter

• US 7,508,586 B2
• Filed: 04/14/2006
• Issued: 03/24/2009
• Est. Priority Date: 04/14/2006
• Status: Active Grant

• Current Assignee: Southwall Technologies, Inc. (Eastman Chemical Company)
• Original Assignee: Southwall Technologies, Inc. (Eastman Chemical Company)
• Inventors: Boehme, Thomas, Thielsch, Roland, Boman, Lee, Stoessel, Chris H.
• Primary Examiner(s): Lavarias; Arnel C
• Application Number:
  US11/404,391
• Publication Number:
  US 20070242359A1
• Time in Patent Office: 1,075 Days
• Field of Search: None
• US Class Current: 359/585
• CPC Class Codes: C03C 17/28 with organic material C03C17/34, C03C17/44 take precedence
• CPC Class Codes: G02B 5/282 reflecting for infrared and transparent for visible light, e.g. heat reflectors, laser protection
• CPC Class Codes: G02B 5/284 of etalon type comprising a resonant cavity other than a thin solid film, e.g. gas, air, solid plates etalons for fibre optic multiplexing G02B6/29358; etalons for spectral measurement G01J3/26

Abstract

An optical filter is formed of a layer stack that includes metallic layers and dielectric layers, with at least one dielectric layer being defined by more than one zinc-based film. These zinc-based films have different percentages of zinc. The selections of the percentages are based upon the positions of the films within the dielectric layer. An unexpectedly low sheet resistance is available if the zinc-based film that immediately precedes forming a metallic layer has a percentage of zinc in the range of 80 percent to next to 100 percent. Process stabilization and manufacturing cost are provided by placing the percentage of the lower zinc-based film closer to 50 percent (25-75). Process stabilization is further enhanced by providing an indium-based film within the dielectric layer adjacent to the metallic layer.

Claims

1. A filtering arrangement comprising:

a transparent substrate; and

a layer stack on said substrate, said layer stack including;

a first metallic layer;

first and second dielectric layers on opposite sides of said first metallic layer, said first dielectric layer being nearer to said substrate than said second dielectric layer, each said dielectric layer including a first zinc-based film and including a second zinc-based film with a greater percentage of zinc than said first zinc-based film so as to function as a seed film for a particular metal, said first metallic layer being a layer of said particular metal, said second dielectric layer including an indium-based film between said first metallic layer and said first zinc-based film of said second dielectric layer, said indium-based film being spaced apart from said second zinc-based film of said second dielectric layer by said first zinc-based film of said second dielectric layer; and

a repeating pattern of layers to achieve a target sheet resistance, said repeating pattern including alternating layers of metal and dielectric.

2. The filtering arrangement of claim 1 wherein said percentage of zinc in said second zinc-based film is in the range between 80 percent and 100 percent.

3. The filtering arrangement of claim 2 wherein a percentage of zinc in said first zinc-based film is in the range of 25 percent to 75 percent.

4. The filtering arrangement of claim 2 wherein said first metallic layer is silver or a silver alloy and said first and second zinc-based layers are zinc-tin layers.

5. The filtering arrangement of claim 1 wherein said first zinc-based film includes an indium-based film between said substrate and said first zinc-based film.

6. The filtering arrangement of claim 1 wherein said substrate is attached to a plasma display panel.

7. The filtering arrangement of claim 1 wherein said filtering arrangement has a total of four said metallic layers and five said dielectric layers.

8. The filtering arrangement of claim 1 wherein each said layer of dielectric of said repeating pattern includes first and second films that are zinc-based, said first film being nearer said substrate than said second film, each said second film having a greater percentage of zinc than said first films.

9. The filtering arrangement of claim 8 wherein each layer of dielectric of said repeating pattern further includes a film that is indium-based and that is nearer to said substrate than said first film.

10. The filtering arrangement of claim 8 wherein each layer of metal in said repeating pattern is a layer of said particular metal.