Separable modulator

• US 7,460,291 B2
• Filed: 08/19/2003
• Issued: 12/02/2008
• Est. Priority Date: 05/05/1994
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Chui, Clarence, Miles, Mark W., Kothari, Manish, Sampsell, Jeffrey Brian
• Primary Examiner(s): Thompson; Timothy J
• Application Number:
  US10/644,312
• Publication Number:
  US 20040051929A1
• Time in Patent Office: 1,932 Days
• Field of Search: 359/291, 359/290, 359/238, 359/223, 359/224, 359/297, 359/298
• US Class Current: 359/291
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G01J 3/26 using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 6/12 of the integrated circuit kind electric integrated circuits H01L27/00
• CPC Class Codes: G02F 1/13725 based on guest-host interaction G02F1/13762, G02F1/13737, take precedence
• CPC Class Codes: G02F 1/216 using liquid crystals, e.g. liquid crystal Fabry-Perot filters
• CPC Class Codes: G02F 2203/03 scattering
• CPC Class Codes: G09G 3/3466 based on interferometric effect

Abstract

A separable modulator architecture is disclosed. The modulator has a mirror suspended from a flexible layer over a cavity. The flexible layer also forms supports and support posts for the mirror. An alternative separable modulator architecture has a mirror suspended over a cavity. The modulator is supported by supports and support posts. The support posts comprise a flexible layer over support post plugs. A bus structure may be formed upon the flexible layer arranged over the support posts.

Claims

1. A light modulator, comprising:

a mirror having first and second surfaces suspended over a cavity arranged under the first surface;

supports attached to the second surface of the mirror;

support posts suspending the mirror over the cavity by the supports, the support posts and supports being formed from a same layer of material; and

an electrode and an optical stack positioned opposite the first surface across the cavity from the mirror such that activation of the electrode causes the mirror to move towards the electrode, changing dimension and interference properties of the cavity.

2. The light modulator of claim 1, the modulator comprising a bus structure attached to the support posts adjacent to the second surface of the mirror.

3. The light modulator of claim 1, the modulator comprising a landing pad arranged upon the electrode and optical stack.

4. The light modulator of claim 3, the landing pad being arranged underneath the mirror.

5. The light modulator of claim 3, the landing pad being arranged so as to contact the supports.

6. A light modulator, comprising:

a mirror having first and second surfaces suspended over a cavity arranged under the first surface;

supports attached to the second surface of the mirror;

support posts suspending the mirror over the cavity by the supports, the support posts having support post plugs; and

an electrode and an optical stack positioned opposite the first surface across the cavity from the mirror such that activation of the electrode causes the mirror to move towards the electrode, changing dimension and interference properties of the cavity.

7. The light modulator of claim 6, the modulator comprising a bus structure attached to the support posts adjacent to the second surface of the mirror.

8. The light modulator of claim 6, the modulator comprising a landing pad arranged upon the electrode and optical stack.

9. The light modulator of claim 8, the landing pad arranged underneath the mirror.

10. The light modulator of claim 8, the landing pad arranged so as to contact the supports.

11. A light modulator, comprising:

a mirror having first and second surfaces suspended over a cavity arranged under the first surface;

supports attached to the second surface of the mirror;

support posts suspending the mirror over the cavity by the supports;

a bus structure attached to the support posts adjacent to the second surface of the mirror; and

an electrode and an optical stack positioned opposite the first surface across the cavity from the mirror such that activation of the electrode causes the mirror to move towards the electrode, changing dimension and interference properties of the cavity.

12. The modulator of claim 11, the support posts being formed from a same layer as the supports.

13. The modulator of claim 11, the support posts being formed by support post plugs.

14. The modulator of claim 11, the modulator comprising a landing pad arranged upon the electrode and optical stack.

15. A method of manufacturing a light modulator, the method comprising:

forming an electrode and optical stack on the back of a transparent substrate;

depositing a first sacrificial layer upon the electrode and optical stack;

forming mirrors on the first sacrificial layer;

depositing a second sacrificial layer upon the mirrors;

forming post holes adjacent to the mirrors;

using a planarization layer to form support post plugs;

depositing a flexible layer on the support post plugs and forming attachments between the flexible layer and the mirror; and

removing the first and second sacrificial layers.

16. The method of claim 15, the method comprising forming bus structures on the flexible layer arranged over the support post plugs.

17. The method of claim 15, forming attachments further comprising forming supports of predetermined mechanical properties such that the mirror assumes a quiescent state at a predetermined vertical position from the electrode and optical stack.

18. The method of claim 15, forming attachments further comprising forming supports with predetermined physical restraints that cause the mirror to move to a predetermined position relative to the electrode and optical stack upon application of a constant voltage.

19. The method of claim 15, the method comprising forming a landing pad array upon the electrode and optical stack.

20. The method of claim 19, forming a landing pad further comprising forming landing pads of varying thicknesses to control an amount of movement of the mirror.

21. The method of claim 15, depositing a first sacrificial layer further comprising depositing three thicknesses of the first sacrificial layer, the thickness deposited for a modulator being dependent upon a color designation of that modulator.

22. A method of manufacturing a light modulator, the method comprising:

forming an electrode and optical stack on the back of a transparent substrate;

depositing a first sacrificial layer upon the electrode and optical stack;

forming mirrors on the first sacrificial layer;

depositing a second sacrificial layer upon the mirrors;

forming post holes adjacent to the mirrors;

depositing a flexible layer on the second sacrificial layer such that attachments between the flexible layer and the mirror are formed and the flexible layer fills the post holes forming support posts; and

removing the first and second sacrificial layers.

23. The method of claim 22, the method comprising forming bus structures on the support posts.

24. The method of claim 22, depositing the flexible layer further comprising depositing the flexible layer and patterning and etching it to provide supports of predetermined mechanical properties such that the mirror assumes a quiescent state at a predetermined vertical position from the electrode and optical stack.

25. The method of claim 22, forming attachments further comprising depositing the flexible layer and patterning and etching it to form supports of predetermined physical restraints that cause the mirror to move to a predetermined position relative to the electrode and optical stack upon application of a constant voltage.

26. The method of claim 22, the method comprising forming a landing pad array upon the electrode and optical stack.

27. The method of claim 26, forming a landing pad array further comprising forming landing pads of varying thicknesses to control an amount of movement of the mirror.

28. The method of claim 22, depositing a first sacrificial layer further comprising depositing three thicknesses of the first sacrificial layer, the thickness deposited for a modulator being dependent upon a color designation of that modulator.

29. A method of manufacturing a light modulator, the method comprising:

forming a mirror over a first sacrificial layer attached to a flexible layer over a second sacrificial layer and having support posts;

depositing a third sacrificial layer over the flexible layer;

forming bus structures in a conductive layer on top of the third sacrificial layer arranged over the support posts; and

removing the sacrificial layers.

30. The method of claim 29, forming a mirror comprising forming a mirror having support posts comprised of a portion of the flexible layer.

31. The method of claim 29, forming a mirror comprising forming a mirror having support post plugs.

32. The method of claim 29, the method comprising forming a landing pad under the first sacrificial layer.