MEMS ANCHOR AND SPACER STRUCTURE

• US 20120295058A1
• Filed: 05/17/2012
• Published: 11/22/2012
• Est. Priority Date: 05/20/2011
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Pixtronix, Incorporated (Qualcomm, Inc.)
• Inventors: Brosnihan, Timothy J., Andersson, Mark B., Fike, Eugene E. III, Wu, Joyce, Steyn, J. Lodewyk
• Granted Patent: US 9,213,181 B2
• Time in Patent Office: Days
• US Class Current: 428/117
• CPC Class Codes: B81B 2201/038 Microengines and actuators not provided for in B81B2201/031 - B81B2201/037
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81B 7/0067 for controlling the passage of optical signals through the package
• CPC Class Codes: B81C 1/00 Manufacture or treatment of devices or systems in or on a substrate B81C3/00 takes precedence
• CPC Class Codes: B81C 1/00039 Anchors
• CPC Class Codes: B81C 1/00261 Processes for packaging MEMS devices MEMS packages B81B7/0032, packaging of smart-MEMS B81C1/0023
• CPC Class Codes: B81C 2203/054 using structural alignment aids, e.g. spacers, interposers, male/female parts, rods or balls
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/3433 using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices using liquid crystal devices G09G3/36; using electrochromic devices G09G3/38
• CPC Class Codes: G09G 3/3466 based on interferometric effect
• CPC Class Codes: H01L 2223/54426 for alignment
• CPC Class Codes: H01L 2224/1132 Screen printing, i.e. using a stencil
• CPC Class Codes: H01L 2224/114 by blanket deposition of the material of the bump connector
• CPC Class Codes: H01L 2224/11462 Electroplating
• CPC Class Codes: H01L 2224/131 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/16238 the bump connector connecting to a bonding area protruding from the surface of the item
• CPC Class Codes: H01L 2224/2612 Auxiliary members for layer connectors, e.g. spacers
• CPC Class Codes: H01L 2224/29011 : comprising apertures or cavities
• CPC Class Codes: H01L 2224/32238 : the layer connector connecting to a bonding area protruding from the surface of the item
• CPC Class Codes: H01L 2224/73201 : on the same surface
• CPC Class Codes: H01L 2224/81121 : Active alignment, i.e. by apparatus steering, e.g. optical alignment using marks or sensors
• CPC Class Codes: H01L 2224/81192 : wherein the bump connectors are disposed only on another item or body to be connected to the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/81815 : Reflow soldering
• CPC Class Codes: H01L 2224/83007 : involving a permanent auxiliary member being left in the finished device, e.g. aids for holding or protecting the layer connector during or after the bonding process
• CPC Class Codes: H01L 2224/83121 : Active alignment, i.e. by apparatus steering, e.g. optical alignment using marks or sensors
• CPC Class Codes: H01L 23/544 : Marks applied to semiconductor devices or parts, e.g. registration marks, alignment structures, wafer maps test patterns for characterising or monitoring manufacturing processes H01L22/00
• CPC Class Codes: H01L 24/11 : Manufacturing methods for bumps on insulating substrates H01L21/4853
• CPC Class Codes: H01L 24/13 : of an individual bump connector
• CPC Class Codes: H01L 24/16 : of an individual bump connector
• CPC Class Codes: H01L 24/32 : of an individual layer connector
• CPC Class Codes: H01L 24/73 : Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 24/81 : using a bump connector
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 24/97 : the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/12043 : Photo diode
• CPC Class Codes: H01L 2924/12044 : OLED
• CPC Class Codes: H01L 2924/1461 : MEMS
• CPC Class Codes: H01L 2924/15788 : Glasses, e.g. amorphous oxides, nitrides or fluorides
• CPC Class Codes: Y10T 428/24157 : Filled honeycomb cells [e.g., solid substance in cavities, etc.]
• CPC Class Codes: Y10T 428/24744 : Longitudinal or transverse tubular cavity or cell

Abstract

A display apparatus includes a first substrate, a plurality of microelectromechanical systems (MEMS) light modulators formed from a structural material coupled to the first substrate and a second substrate separated from the first substrate. A plurality of spacers extend from the first substrate to keep the second substrate a minimum distance away from the plurality of light modulators. The spacers include a first polymer layer having a surface in contact with the first substrate, a second polymer layer encapsulating the first polymer layer and a layer of the structural material encapsulating the second polymer layer. The spacers can be used as fluid barriers and configured to surround more than one but less than all of the MEMS light modulators in the display apparatus.

Claims

1. A display apparatus comprising:

a first substrate;

a plurality of microelectromechanical system (MEMS) light modulators formed from a structural material coupled to the first substrate;

a second substrate separated from the first substrate; and

a plurality of spacers extending from the first, the spacers including;

a first polymer layer having a surface in contact with the first substrate;

a second polymer layer encapsulating the first polymer layer; and

a layer of the structural material encapsulating the second polymer layer.

2. The display apparatus of claim 1, wherein the second polymer layer encapsulates the first polymer layer by covering all surfaces of the first polymer layer not substantially in contact with the first substrate.

3. The display apparatus of claim 1, wherein the layer of the structural material encapsulates the second polymer layer by covering all surfaces of the first polymer layer not substantially in contact with an exterior surface of the second polymer layer.

4. The display apparatus of claim 1, wherein at least one of the plurality of spacers comprises an anchor for suspending at least one of the plurality of MEMS light modulators over the first substrate.

5. The display apparatus of claim 1, wherein at least one of the first polymer layer and the second polymer layer includes a resist layer.

6. The display apparatus of claim 1, wherein the layer of the structural material includes at least one of a semiconductor layer and a metal layer.

7. The display apparatus of claim 1, wherein the layer of the structural material comprises at least one of silicon (Si), aluminum (Al), aluminum oxide (Al₂O₃), titanium (Ti), silicon nitride (SiN), and an oxynitride (OxNy).

8. The display apparatus of claim 1, wherein the metallic layer absorbs at least about 80% of light impinging on the layer of the structural material.

9. The display apparatus of claim 1, wherein the layer of the structural material is a plasma enhanced chemical vapor deposition (PECVD)-deposited layer.

10. The display apparatus of claim 1, wherein the plurality of spacers are sized to keep the second substrate at least a minimum distance away from the plurality of light modulators.

11. An apparatus comprising:

a first substrate;

at least one microelectromechanical system (MEMS) device formed from a structural material and coupled to the first substrate;

a second substrate separated from the first substrate; and

a plurality of spacers extending from the first substrate, the spacers including a first polymer layer, a second polymer layer and a plasma enhanced chemical vapor deposition (PECVD)-deposited layer of the structural material which substantially encapsulates the first and second polymer layers.

12. The apparatus of claim 11, wherein:

the first polymer layer includes a surface in contact with the first substrate; and

the second polymer layer encapsulates the first polymer layer.

13. The apparatus of claim 11, wherein the second polymer layer encapsulates the first polymer layer by covering all surfaces of the first polymer layer not substantially in contact with the first substrate.

14. The apparatus of claim 11, wherein at least one of the first polymer layer and the second polymer layer includes a resist layer.

15. The apparatus of claim 11, wherein the layer of the structural material includes at least one of a semiconductor layer and a metal layer.

16. The apparatus of claim 11, wherein the layer of the structural material comprises at least one of silicon (Si), titanium (Ti), silicon nitride (SiN), and an oxynitride (OxNy).

17. The apparatus of claim 11, wherein the metallic layer absorbs at least about 80% of light impinging on the layer of the structural material.

18. The apparatus of claim 11, wherein the plurality of spacers are sized to keep the second substrate at least a minimum distance away from the MEMS device.

19. An apparatus comprising:

a first substrate;

at least one microelectromechanical system (MEMS) device formed from a light absorbing structural material and supported over the first substrate;

a second substrate separated from the first substrate; and

a plurality of spacers extending from the first substrate the spacers including;

a first polymer layer having a surface in contact with the first substrate;

a second polymer layer; and

a layer of the light absorbing structural material encapsulating the first and second polymer layers, the layer of the light absorbing structural material absorbing at least about 80% of light impinging on the light absorbent layer of the structural material.

20. The apparatus of claim 19, wherein at least one of the first polymer layer and the second polymer layer includes a resist layer.

21. The apparatus of claim 19, wherein the second polymer layer encapsulates the first polymer layer.

22. The apparatus of claim 19, wherein the light absorbent layer of the structural material comprises at least one silicon (Si), titanium (Ti), silicon nitride (SiN), and an oxynitride (OxNy).

23. The apparatus of claim 19, wherein the layer of the light absorbing structural material is a plasma enhanced chemical vapor deposition (PECVD)-deposited layer.

24. The apparatus of claim 19, wherein the plurality of spacers are sized to keep the second substrate at least a minimum distance away from the MEMS device.

25. An apparatus comprising:

a first substrate;

at least one microelectromechanical system (MEMS) device formed from a structural material and connected to the first substrate;

a second substrate separated from the first substrate; and

a plurality of spacers extending from the first substrate, the plurality of spacers including;

a first polymer layer having a surface in contact with the first substrate;

a second polymer layer having a surface in contact with the first polymer layer; and

a plasma enhanced chemical vapor deposition (PECVD)-deposited layer of the structural material encapsulating the first and second polymer layers.

26. The apparatus of claim 25, wherein the second polymer layer encapsulates the first polymer layer by covering all surfaces of the first polymer layer not substantially in contact with the first substrate.

27. The apparatus of claim 25, wherein at least one of the first polymer layer and the second polymer layer includes a resist layer.

28. The apparatus of claim 25, wherein the light absorbent layer of the structural material includes at least one of a semiconductor layer and a metal layer.

29. The apparatus of claim 25, wherein the layer of the structural material comprises at least one of silicon (Si), titanium (Ti), silicon nitride (SiN), and an oxynitride (OxNy).

30. The apparatus of claim 25, wherein the layer of structural material absorbs at least about 80% of light impinging on the layer of the structural material.

31. The apparatus of claim 25, wherein the plurality of spacers are sized to keep the second substrate at least a minimum distance away from the MEMS device.

32. A display apparatus comprising:

a first substrate;

a plurality of microelectromechanical system (MEMS) light modulators formed from a structural material coupled to the first substrate;

a second substrate separated from the first substrate; and

at least one anchor for suspending at least one of the plurality of MEMS light modulators over the first substrate, the anchor including;

a first polymer layer having a surface in contact with the first substrate;

a second polymer layer having a surface in contact with the first polymer layer; and

a layer of the structural material encapsulating the first and second polymer layers.

33. The display apparatus of claim 32, wherein the second polymer layer encapsulates the first polymer layer by covering all surfaces of the first polymer layer not substantially in contact with the first substrate.

34. The display apparatus of claim 32, wherein at least one of the first polymer layer and the second polymer layer includes a resist layer.

35. The display apparatus of claim 32, wherein the layer of the structural material includes at least one of a semiconductor layer and a metal layer.

36. The display apparatus of claim 32, wherein the layer of the structural material comprises at least one of silicon (Si), aluminum (Al), aluminum oxide (Al₂O₃), titanium (Ti), silicon nitride (SiN), and an oxynitride (OxNy).

37. The display apparatus of claim 32, wherein the layer of the structural material absorbs at least about 80% of light impinging on the layer of the structural material.

38. The display apparatus of claim 32, wherein the layer of the structural material is a plasma enhanced chemical vapor deposition (PECVD)-deposited layer.

39. A display apparatus comprising:

a first substrate;

a plurality of microelectromechanical system (MEMS) light modulators suspended over the first substrate;

a second substrate separated from the first substrate; and

a fluid barrier substantially enclosing more than one but less than all of the MEMS light modulators, wherein the fluid barrier extends from the first substrate and is configured for interfering with flow of fluid across the display towards the enclosed MEMS light modulators.

40. The display apparatus of claim 39, wherein the fluid barrier has a height over the first substrate substantially equivalent to a height of the plurality of MEMS light modulators over the first substrate.

41. The display apparatus of claim 39, wherein the fluid barrier comprising a plurality of discontinuous barrier structures separated by openings there between.

42. The apparatus of claim 39, wherein at least one of the plurality of discontinuous barrier structures comprises:

a first polymer layer having a surface in contact with the first substrate;

a second polymer layer encapsulating the first polymer layer; and

a layer of the structural material encapsulating the second polymer.

43. The display apparatus of claim 39, wherein the second polymer layer encapsulates the first polymer layer.

44. An apparatus comprising:

a first substrate;

a plurality of microelectromechanical system (MEMS) devices connected to the first substrate and formed from a structural material;

a second substrate separated from the first substrate; and

a fluid barrier comprising a plurality of spacers comprising a first polymer layer, a second polymer layer and a layer of the structural material, wherein the first polymer layer is encapsulated by the first substrate and the layer of the structural material.

45. The apparatus of claim 44, wherein the plurality of spacers form a substantially continuous barrier around at least one MEMS device.

46. The apparatus of claim 44, wherein the plurality of spacers is configured to substantially enclose more than one MEMS device and less than all of the plurality of MEMS devices.

47. An apparatus comprising:

a first substrate;

a plurality of microelectromechanical system (MEMS) devices supported by the first substrate;

a second substrate separated from the first substrate; and

a fluid barrier comprising a plurality of spacers configured to substantially enclose more than one MEMS device and less than all of the plurality of MEMS devices.

48. The apparatus of claim 47, wherein the plurality of spacers form a substantially contiguous barrier around at least one MEMS device.

49. The apparatus of claim 47, wherein the plurality of MEMS devices are formed from a structural material and at least one of the plurality of spacers comprises a first polymer layer, a second polymer layer and a layer of structural material.

50. The apparatus of claim 49, wherein the second polymer layer encapsulates the first polymer layer.

51. A method for manufacturing a display assembly comprising:

forming an anchor and a spacer that includes a first polymer layer and a second polymer layer encapsulated by a layer of structural material, wherein forming the anchor and the spacer comprises

depositing the first polymer layer on the first transparent substrate;

patterning and curing the first polymer layer;

after patterning and curing the first polymer layer, depositing the second polymer layer on the first transparent substrate and on top of the remainder of the first polymer layer;

patterning and curing the second polymer layer;

depositing a layer of structural material over the first polymer layer and the second polymer layer using plasma enhanced chemical vapor deposition (PECVD);

patterning and etching the layer of structural material to form the anchor and the spacer; and

removing remaining portions of the first and second polymer layers to release the anchor and the spacer such that the spacer includes the first polymer layer and the second polymer layer substantially encapsulated by the layer of structural material.

52. The method of claim 51, wherein at least one of the first polymer layer and the second polymer layer includes a resist.

53. The method of claim 51, wherein the layer of structural material comprises a light absorbing material that absorbs at least about 80% of light impinging on the layer of structural material.

54. The method of claim 51, wherein depositing the second polymer layer on top of the remainder of the first polymer layer comprises depositing the second polymer layer on the first transparent substrate on top of the remainder of the first polymer layer such that portions of the cured first polymer layer are encapsulated by the remaining portions of the second polymer layer.