Wafer encapsulated microelectromechanical structure and method of manufacturing same

• US 20070181962A1
• Filed: 10/12/2006
• Published: 08/09/2007
• Est. Priority Date: 01/20/2006
• Status: Abandoned Application

• Current Assignee: Aaron Partridge, Markus Lutz, Pavan Gupta
• Original Assignee: Aaron Partridge, Markus Lutz, Pavan Gupta
• Inventors: Partridge, Aaron, Lutz, Markus, Gupta, Pavan
• Application Number:
  US11/580,197
• Publication Number:
  US 20070181962A1
• Time in Patent Office: Days
• US Class Current: 257/414
• CPC Class Codes: B81B 2201/0271 Resonators; ultrasonic resonators
• CPC Class Codes: B81B 2203/0315 Cavities
• CPC Class Codes: B81B 2203/04 Electrodes
• CPC Class Codes: B81B 2207/07 Interconnects
• CPC Class Codes: B81B 7/0035 for maintaining a controlled atmosphere inside of the chamber containing the MEMS
• CPC Class Codes: B81B 7/0058 for protecting against damages due to external chemical or mechanical influences, e.g. shocks or vibrations
• CPC Class Codes: B81B 7/007 Interconnections between the MEMS and external electrical signals
• CPC Class Codes: B81C 1/00269 Bonding of solid lids or wafers to the substrate
• CPC Class Codes: B81C 1/00277 for maintaining a controlled atmosphere inside of the cavity containing the MEMS
• CPC Class Codes: B81C 1/00301 Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
• CPC Class Codes: B81C 2201/0171 Doping materials
• CPC Class Codes: B81C 2203/031 Anodic bondings
• CPC Class Codes: B81C 2203/036 Fusion bonding
• CPC Class Codes: B81C 2203/037 Thermal bonding techniques not provided for in B81C2203/035 - B81C2203/036
• CPC Class Codes: B81C 2203/038 Bonding techniques not provided for in B81C2203/031 - B81C2203/037
• CPC Class Codes: H01L 23/051 another lead being formed by a cover plate parallel to the base plate, e.g. sandwich type
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H10N 30/306 Cantilevers

Abstract

There are many inventions described and illustrated herein. In one aspect, the present inventions relate to devices, systems and/or methods of encapsulating and fabricating electromechanical structures or elements, for example, accelerometer, gyroscope or other transducer (for example, pressure sensor, strain sensor, tactile sensor, magnetic sensor and/or temperature sensor), filter or resonator. The fabricating or manufacturing microelectromechanical systems of the present invention, and the systems manufactured thereby, employ wafer bonding encapsulation techniques.

Claims

1-30. -30. (canceled)

31. A microelectromechanical device comprising:

a first substrate;

a chamber;

an inert gas disposed in the chamber;

a microelectromechanical structure, wherein the microelectromechanical structure is (i) formed from a portion of the first substrate and (ii) at least partially disposed in the chamber;

a second substrate, bonded to the first substrate, wherein a surface of the second substrate forms a wall of the chamber; and

a contact, wherein;

a first portion of the contact is (i) formed from a portion of the first substrate and (ii) at least a portion thereof is disposed outside the chamber; and

a second portion of the contact is formed from a portion of the second substrate.

32. The microelectromechanical device of claim 31 wherein the second substrate includes carbon, polycrystalline silicon, porous polycrystalline silicon, amorphous silicon, silicon carbide, silicon/germanium, germanium, or gallium arsenide.

33. The microelectromechanical device of claim 32 wherein the first substrate includes carbon, polycrystalline silicon, porous polycrystalline silicon, amorphous silicon, silicon carbide, silicon/germanium, germanium, or gallium arsenide.

34. The microelectromechanical device of claim 32 wherein:

the first portion of the contact is a semiconductor material having a first conductivity;

the second substrate is a semiconductor material having a second conductivity; and

the second portion of the contact is a semiconductor material having the first conductivity.

35. The microelectromechanical device of claim 34 wherein the second portion of the contact is polycrystalline or monocrystalline silicon that is counterdoped to include the first conductivity.

36. The microelectromechanical device of claim 31 further including a trench, disposed in the second substrate and around at least a portion of the second portion of the contact.

37. The microelectromechanical device of claim 36 wherein the trench includes a first material disposed therein to electrically isolate the second portion of the contact from the second substrate.

38. The microelectromechanical device of claim 36 wherein the first material includes an insulation material.

39. The microelectromechanical device of claim 31 wherein the first substrate is a semiconductor on insulator substrate.

40. The microelectromechanical device of claim 31 wherein the first and second substrates are bonded using fusion bonding, anodic-like bonding, silicon direct bonding, soldering, thermo compression, thermo-sonic, laser bonding and/or glass reflow.

41. The microelectromechanical device of claim 31 wherein the inert gas is disposed in the chamber at a predetermined pressure.

42. The microelectromechanical device of claim 41 wherein the predetermined pressure of the inert gas is adjusted by an annealing process.

43. A microelectromechanical device comprising:

a first substrate, wherein the first substrate includes a first material and an insulation layer disposed thereon;

a chamber;

an inert gas disposed in the chamber;

a microelectromechanical structure, wherein the microelectromechanical structure is (i) formed from a portion of the first substrate and (ii) at least partially disposed in the chamber;

a second substrate, bonded to the first substrate, wherein a surface of the second substrate forms a wall of the chamber; and

a cavity (i) formed in the insulation layer and (ii) forming a portion of the chamber.

44. The microelectromechanical device of claim 43 wherein the first substrate is a semiconductor on insulator substrate and wherein the first material is a semiconductor.

45. The microelectromechanical device of claim 43 wherein the insulation layer is formed, grown and/or deposited on the first material.

46. The microelectromechanical device of claim 43 wherein:

the first material comprises carbon, polycrystalline silicon, monocrystalline silicon, amorphous silicon, silicon carbide, silicon/germanium, germanium, or gallium arsenide;

the insulation layer includes oxygen or nitrogen; and

the second substrate comprises carbon, polycrystalline silicon, monocrystalline silicon, amorphous silicon, silicon carbide, silicon/germanium, germanium, or gallium arsenide.

47. The microelectromechanical device of claim 43 wherein the second substrate is fusion bonded, anodic-like bonded, silicon direct bonded, soldered, thermo compression bonded, thermo-sonic bonded, laser bonding and/or glass reflowed to the first substrate.

48. The microelectromechanical device of claim 43 wherein the inert gas is disposed in the chamber at a predetermined pressure.

49. The microelectromechanical device of claim 48 wherein the predetermined pressure of the inert gas is adjusted by an annealing process.

50. A microelectromechanical device comprising:

a first substrate;

a chamber;

an inert gas disposed in the chamber;

a microelectromechanical structure, wherein the microelectromechanical structure is (i) formed from a portion of the first substrate and (ii) at least partially disposed in the chamber;

a second substrate, bonded to the first substrate, wherein a surface of the second substrate forms a wall of the chamber;

a trench, disposed in the second substrate; and

an isolation region, disposed in or on the first substrate and aligned with the trench.

51. The microelectromechanical device of claim 50 wherein the first substrate comprises carbon, polycrystalline silicon, monocrystalline silicon, amorphous silicon, silicon carbide, silicon/germanium, germanium, or gallium arsenide.

52. The microelectromechanical device of claim 51 wherein the second substrate comprises carbon, polycrystalline silicon, monocrystalline silicon, amorphous silicon, silicon carbide, silicon/germanium, germanium, or gallium arsenide.

53. The microelectromechanical device of claim 50 wherein the first substrate is a semiconductor on insulator substrate.

54. The microelectromechanical device of claim 50 wherein the second substrate is a semiconductor material having a first conductivity and the trench is (i) a semiconductor material having a second conductivity or (ii) an insulation material.

55. The microelectromechanical device of claim 50 wherein the second substrate is a semiconductor material having a first conductivity and the isolation region is a semiconductor material having a second conductivity.

56. The microelectromechanical device of claim 55 wherein the trench is a semiconductor material having the second conductivity.

57. The microelectromechanical device of claim 50 wherein the trench includes an insulation material wherein the trench defines, at least in part, a contact area.

58. The microelectromechanical device of claim 50 wherein the isolation region includes an insulation material.

59. The microelectromechanical device of claim 50 further comprising a contact, wherein a portion of the contact is formed from a portion of the second substrate.

60. The microelectromechanical device of claim 59 wherein the trench is disposed around at least a portion of the portion of the contact.

61. The microelectromechanical device of claim 60 wherein the portion of the contact is a semiconductor material having a first conductivity, the second substrate is a semiconductor material having the first conductivity and the trench is a semiconductor material having a second conductivity.

62. The microelectromechanical device of claim 60 wherein the portion of the contact is a semiconductor material having a first conductivity, the second substrate is a semiconductor material having the first conductivity and the isolation region is a semiconductor material having a second conductivity.

63. The microelectromechanical device of claim 50 wherein the trench includes (i) a semiconductor material having the second conductivity or (ii) an insulation material.

64. The microelectromechanical device of claim 50 wherein the first substrate includes an insulation layer and wherein the second substrate is bonded to a surface of the insulation layer.

65. The microelectromechanical device of claim 64 wherein the insulation layer includes a cavity formed therein and wherein the cavity forms a portion of the chamber.

66. The microelectromechanical device of claim 50 wherein the inert gas is disposed in the chamber at a predetermined pressure.

67. The microelectromechanical device of claim 66 wherein the predetermined pressure of the inert gas is adjusted by an annealing process.