Method of fabricating optical filters

• US 20050003665A1
• Filed: 06/02/2004
• Published: 01/06/2005
• Est. Priority Date: 05/19/2000
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Dan A. Steinberg, David W Sherrer, Mindaugas F. Dautartas
• Inventors: Sherrer, David W., Steinberg, Dan A., Dautartas, Mindaugas F.
• Granted Patent: US 7,267,781 B2
• Time in Patent Office: Days
• US Class Current: 438/689
• 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

A method of fabricating optical filter is disclosed. The method includes providing the substrate and selectively etching the substrate to form a plurality of freestanding layers. A plurality of dielectric layers is disposed over an outer surface of each of the freestanding layers. The resultant optical filters may be used in a variety of applications including etalon applications.

Claims

1. A method of fabricating optical filters comprising:

providing a substrate;

etching said substrate to form a plurality of freestanding layers; and

depositing a plurality of dielectric layers over an outer surface of each of said freestanding layers.

2. A method as recited in claim 1, further comprising removing said freestanding layers with said plurality of dielectric layers from said substrate.

3. A method as recited in claim 1, wherein said substrate is silicon.

4. A method as recited in claim 1, wherein said freestanding layers have side surfaces in defined crystalline planes.

5. A method as recited in claim 1, wherein said depositing is carried out using a method of the group consisting essentially of:

ALD, CVD, LPCVD, PECVD and MOCVD.

6. A method as recited in claim 1, wherein said plurality of dielectric layer further comprises 10 to 100 layers.

7. A method as recited in claim 1, wherein said substrate is monocrystalline silicon.

8. A method as recited in claim 1, wherein said substrate has a <

110>

top surface.

9. A method as recited in claim 1, wherein said freestanding layers have sidewalls in the <

111>

crystalline plane.

10. A method as recited in claim 9, wherein said planes are substantially vertical.

11. A method as recited in claim 9, wherein said freestanding layers have a substantially trapezoidal cross-section.

12. A method as recited in claim 1, wherein said plurality of dielectric layers is chosen from the group consisting essentially of aluminum oxide, titanium oxide, silicon oxide, cesium oxide and tantalum oxide.

13. A method as recited in claim 1, wherein said freestanding layers is silicon and the method further comprises oxidizing said silicon prior to depositing said plurality of dielectric layers.

25. A method as recited in claim 1, wherein said etching further comprises dry etching a plurality of holes through said substrate followed by anisotropically etching said holes.

26. A method as recited in claim 25, wherein said anisotropic etching is a wet etching step.

14. A method of fabricating an optical etalon, the method comprising:

providing a substrate;

selectively etching said substrate to form at least two substantially parallel freestanding layers and handles; and

depositing a plurality of dielectric layers over an outer surface of said freestanding layers.

15. A method as recited in claim 14, wherein said freestanding layers have side surfaces in defined crystalline planes.

16. A method as recited in claim 14, wherein said depositing is carried out using a method of the group consisting essentially of:

ALD, CVD, LPCVD, PECVD and MOCVD.

17. A method as recited in claim 14, wherein a distance between said at least two freestanding layers is substantially fixed.

18. A method as recited in claim 14, wherein a distance between said at least two freestanding layers is variable.

19. A method as recited in claim 18, further comprising depositing a layer of transparent conductive material over said at least two freestanding layers.

20. A method as recited in claim 14, wherein said plurality of dielectric layers is chosen from the group consisting essentially of aluminum oxide, titanium oxide, silicon oxide, cesium oxide and tantalum oxide.

21. A method of fabricating an etalon, the method comprising:

providing a substrate;

selectively etching said substrate to form at least one freestanding layer;

depositing a plurality of dielectric layers over said at least one freestanding layer on opposed sidewalls of said freestanding layer; and

removing said freestanding layer.

22. A method as recited in claim 21, wherein said at least one freestanding layer has a thickness, and said thickness equals a spacing of the etalon.

23. A method as recited in claim 21, wherein said sidewalls are in defined crystalline planes.

24. A method as recited in claim 21, wherein said sidewalls are substantially parallel.