Optical device and method of forming the same

• US 20070267057A1
• Filed: 05/17/2006
• Published: 11/22/2007
• Est. Priority Date: 05/17/2006
• Status: Abandoned Application

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Haluzak, Charles C., Mardilovich, Peter, Sterner, John R., Kelly, Conor
• Application Number:
  US11/435,655
• Publication Number:
  US 20070267057A1
• Time in Patent Office: Days
• US Class Current: 136/255
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81B 3/0083 Optical properties
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001

Abstract

An optical device includes a first substrate and a sub-wavelength form-birefringent metal oxide retarder plate formed on at least a portion of the substrate. A silicon oxide or silicon oxynitride layer contacts at least a surface of the retarder plate, and a second substrate, having at least one micro-electro-mechanical system device, is bonded to the silicon oxide or silicon oxynitride layer via a second silicon oxide or silicon oxynitride layer.

Claims

1. An optical device, comprising:

a first substrate;

a sub-wavelength form-birefringent metal oxide retarder plate formed on at least a portion of the substrate;

a silicon oxide or silicon oxynitride layer contacting at least a surface of the retarder plate; and

a second substrate having at least one micro-electro-mechanical system chip, the second substrate being bonded to the silicon oxide or silicon oxynitride layer via a second silicon oxide or silicon oxynitride layer.

2. The optical device as defined in claim 1 wherein the retarder plate is selected from tantalum pentoxide, aluminum oxide, zinc oxide, tungsten oxide, or niobium oxide.

3. The optical device as defined in claim 1 wherein the metal oxide retarder plate has a predetermined retarder plate design including a plurality of nano-structured pillars having spaces therebetween.

4. The optical device as defined in claim 3 wherein the silicon oxide or silicon oxynitride layer is established so that the spaces are at least partially filled.

5. The optical device as defined in claim 1 wherein the at least one micro-electro-mechanical system chip is selected from light modulators, Fabry-Perot chips, micro-opto-electromechanical systems, micromirrors, micro-actuators, bio-MEMS-optical arrays, and combinations thereof.

6. The optical device as defined in claim 1 wherein the sub-wavelength form-birefringent metal oxide retarder plate is formed on a center portion of the substrate, and the optical device further comprises a metal oxide layer established on an edge of the substrate.

7. The optical device as defined in claim 1 wherein the at least one micro-electro-mechanical system chip is hermetically sealed after bonding.

8. The optical device as defined in claim 1, further comprising:

a second sub-wavelength form-birefringent metal oxide retarder plate formed on at least a portion of the silicon oxide or silicon oxynitride layer, the second sub-wavelength form-birefringent metal oxide retarder plate rotated at a non-zero angle with respect to a position of the sub-wavelength form-birefringent metal oxide retarder plate; and

a third silicon oxide or silicon oxynitride layer contacting at least a surface of the second retarder plate, wherein the second substrate is bonded to the third silicon oxide or silicon oxynitride layer via the second silicon oxide or silicon oxynitride layer.

9. The optical device as defined in claim 1 wherein the sub-wavelength form-birefringent metal oxide retarder plate is a quarter-wave plate.

10. A method for forming an optical device, comprising:

forming a metal oxide retarder plate on at least a portion of a first substrate;

establishing a silicon oxide or silicon oxynitride layer on at least a surface of the retarder plate;

planarizing the silicon oxide or silicon oxynitride layer; and

bonding the silicon oxide or silicon oxynitride layer to a second substrate via a second silicon oxide or silicon oxynitride layer, the second substrate having a micro-electro-mechanical system chip.

11. The method as defined in claim 10 wherein forming the retarder plate is accomplished by:

establishing a metal layer on the substrate;

establishing a resist layer having a predetermined retarder plate design on at least a portion of the metal layer;

selectively etching at least a portion of the metal layer to form a patterned metal layer having the predetermined retarder plate design;

removing the resist layer; and

anodically oxidizing the patterned metal layer to form the metal oxide retarder plate.

12. The method as defined in claim 11 wherein the metal layer is selectively etched to form the patterned metal layer having the predetermined retarder plate design formed in a center thereof.

13. The method as defined in claim 11 wherein establishing the resist layer on the metal layer is accomplished by:

depositing the resist layer on the metal layer; and

nano-imprinting the resist to form the predetermined retarder plate design.

14. The method as defined in claim 10 wherein forming the retarder plate is accomplished by:

establishing a metal layer on the substrate;

establishing a resist layer having a predetermined retarder plate design on at least a portion of the metal layer so that areas of the metal layer remain exposed;

anodically oxidizing the exposed areas of the metal layer, thereby forming a metal oxide having the predetermined retarder plate design;

removing the resist layer; and

removing unoxidized areas of the metal layer.

15. The method as defined in claim 10 wherein the retarder plate includes a plurality of nano-structured pillars having spaces therebetween, and wherein the silicon oxide or silicon oxynitride layer is established so that the spaces are at least partially filled.

16. The method as defined in claim 10 wherein the retarder plate has a predetermined form-birefringent property.

17. The method as defined in claim 10 wherein bonding hermetically seals the micro-electro-mechanical system chip within the optical device.

18. The method as defined in claim 10 wherein bonding is accomplished by plasma-assisted bonding or silicate bonding.

19. The method as defined in claim 10 wherein the second substrate is bonded to an outermost layer of a plurality of silicon oxide or silicon oxynitride layers, and wherein prior to bonding the second substrate, the method further comprises:

forming one of a plurality of metal oxide retarder plates on at least a portion of the silicon oxide or silicon oxynitride layer, the one of the plurality of retarder plates rotated at a non-zero angle with respect to the retarder plate;

establishing one of the plurality of silicon oxide or silicon oxynitride layers on at least a surface of the one of the plurality of retarder plates; and

planarizing the one of the plurality of silicon oxide or silicon oxynitride layers.

20. The method as defined in claim 19, further comprising;

forming an other of the plurality of metal oxide retarder plates on at least a portion of the one of the plurality of silicon oxide or silicon oxynitride layers, the other of the plurality of retarder plates rotated at a non-zero angle with respect to the retarder plate and the one of the plurality of retarder plates;

establishing an other of the plurality of second silicon oxide or silicon oxynitride layers on at least a surface of the other of the plurality of retarder plates; and

planarizing the other of the plurality of second silicon oxide or silicon oxynitride layers.