MICRO-ELECTRO MECHANICAL TUNNELING SWITCH

• US 20080135386A1
• Filed: 11/20/2007
• Published: 06/12/2008
• Est. Priority Date: 11/20/2006
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Muldavin, Jeremy, Bozler, Carl O., Keast, Craig L.
• Granted Patent: US 8,432,239 B2
• Time in Patent Office: Days
• US Class Current: 200/181
• CPC Class Codes: B81B 2201/014 having a cantilever fixed on one side connected to one or more dimples
• CPC Class Codes: B81B 3/001 Structures having a reduced contact area, e.g. with bumps or with a textured surface
• CPC Class Codes: H01H 2059/0063 with stepped actuation, e.g. actuation voltages applied to different sets of electrodes at different times or different spring constants during actuation
• CPC Class Codes: H01H 2059/0072 with stoppers or protrusions for maintaining a gap, reducing the contact area or for preventing stiction between the movable and the fixed electrode in the attracted position
• CPC Class Codes: H01H 59/0009 making use of micromechanics

Abstract

A micro-electromechanical system switch includes a substrate and a plurality of actuating electrodes formed the substrate wherein each actuating electrode is activatable. A cantilever beam has a first end and a second end and a plurality of stops formed thereon. The plurality of stops engages the substrate between the plurality of actuating electrode. A contact area is formed in the substrate and located to engage the second end of the cantilever beam. A voltage source applies a voltage to each actuating electrode independently in a sequence from an actuating electrode located adjacent to the first end of the cantilever beam to an actuating electrode located adjacent to the second end of the cantilever beam so that the plurality of stops sequentially engage the substrate between the plurality of actuating electrodes.

Claims

1. A micro-electromechanical system switch, comprising:

a substrate;

a plurality of actuating electrodes formed said substrate, each actuating electrode being activatable;

a cantilever beam having a first end and a second end;

a plurality of stops formed on said cantilever beam to engage said substrate between said plurality of actuating electrodes; and

a contact area formed in said substrate and located to engage said second end of said cantilever beam.

2. The micro-electromechanical system switch as claimed in claim 1, further comprising a voltage source to apply a voltage to each actuating electrode independently in a sequence from an actuating electrode located adjacent to said first end of said cantilever beam to an actuating electrode located adjacent to said second end of said cantilever beam so that said plurality of stops sequentially engage said substrate between said plurality of actuating electrodes.

3. The micro-electromechanical system switch as claimed in claim 2, wherein a gap is formed between a second end of said cantilever beam and said contact area when all actuating electrodes, but the actuating electrode located adjacent to said second end of said cantilever beam, have been actuated.

4. The micro-electromechanical system switch as claimed in claim 3, wherein said gap is less than 100 nm.

5. The micro-electromechanical system switch as claimed in claim 3, wherein said gap is 1 to 30 nm.

6. The micro-electromechanical system switch as claimed in claim 2, wherein an effective gap is formed between a second end of said cantilever beam and said contact area when all actuating electrodes have been actuated.

7. The micro-electromechanical system switch as claimed in claim 6, wherein said effective gap is less than 1 nm.

8. The micro-electromechanical system switch as claimed in claim 6, wherein said effective gap substantially prevents metal atoms in said second end of said cantilever from physically contacting metal atoms in said contact area.

9. The micro-electromechanical system switch as claimed in claim 1, further comprising a voltage source to apply a voltage to each actuating electrode independently in a sequence from an actuating electrode located adjacent to said first end of said cantilever beam to an actuating electrode located adjacent to said second end of said cantilever beam so that the micro-electromechanical system switch closes in stages.

10. The micro-electromechanical system switch as claimed in claim 1, wherein said cantilever beam is a multi-metal cantilever beam.

11. The micro-electromechanical system switch as claimed in claim 1, wherein said cantilever beam is constructed of a first layer of titanium formed upon a second layer of aluminum, which is formed upon a third layer of titanium.

12. The micro-electromechanical system switch as claimed in claim 1, wherein said cantilever beam is constructed of a first layer of titanium formed upon a second layer of tungsten, which is formed upon a third layer of titanium.

13. The micro-electromechanical system switch as claimed in claim 1, wherein said plurality of stops is constructed of platinum.

14. The micro-electromechanical system switch as claimed in claim 1, wherein said contact area includes an anti-stick layer formed thereon.

15. The micro-electromechanical system switch as claimed in claim 14, wherein said anti-stick layer is constructed of a silicon dioxide monolayer.

16. The micro-electromechanical system switch as claimed in claim 14, wherein said anti-stick layer is constructed of a monolayer layer of carbon.

17. The micro-electromechanical system switch as claimed in claim 14, wherein said anti-stick layer is constructed of a monolayer layer of oxygen.

18. The micro-electromechanical system switch as claimed in claim 1, wherein said cantilever beam includes strain relieving slits.

19. The micro-electromechanical system switch as claimed in claim 1, wherein said first end of said cantilever beam is thinner than said second end of said cantilever beam.

20. The micro-electromechanical system switch as claimed in claim 1, wherein a thickness of said cantilever beam increase from said first end of said cantilever beam to said second end of said cantilever beam.

21. A switch comprising:

a first contact;

a second contact; and

an anti-stick layer formed on said second contact.

22. The switch as claimed in claim 21, wherein said anti-stick layer is constructed of a silicon dioxide monolayer.

23. The switch as claimed in claim 21, wherein said anti-stick layer is constructed of a monolayer layer of carbon.

24. The switch as claimed in claim 21, wherein said anti-stick layer is constructed of a monolayer layer of oxygen.

25. The switch as claimed in claim 21, wherein an effective gap of less than 1 nm is formed by said anti-stick layer.

26. The switch as claimed in claim 21, wherein an effective gap is formed by said anti-stick layer;

said effective gap substantially preventing metal atoms in said second contact from physically contacting metal atoms in said first contact.

27. A switch comprising:

a first contact; and

a second contact;

said first and said second contact having an effective gap therebetween when said first and second contacts provide a closed switch.

28. The switch as claimed in claim 27, wherein the effective gap is an anti-stick layer formed on said second contact.

29. The switch as claimed in claim 27, wherein the effective gap is an anti-stick layer formed on said first contact.

30. The switch as claimed in claim 27, wherein the effective gap substantially prevents metal atoms in said first and second contacts from actual physical contact.

31. The switch as claimed in claim 27, wherein the effective gap is realized by said first and second contacts are non-atomically smooth.

32. The switch as claimed in claim 27, wherein said first and said second contact having a gap therebetween which is less than 50 nm when said first and second contacts provide an open switch.

33. A sealed micro-electromechanical system switch, comprising:

a substrate;

a metal plug embedded in said substrate;

a moving contact engaging a first end of said metal plug;

a fixed contact being separated from a second end of said metal plug by a gap;

an actuating electrode embedded in said substrate;

a voltage source to apply a voltage to said actuating electrode so as to cause said metal plug to move to provide an electrical engagement between said fixed contact and said metal plug.

34. The sealed micro-electromechanical system switch as claimed in claim 33, wherein said metal plug is constructed of platinum.

35. The sealed micro-electromechanical system switch as claimed in claim 33, wherein said moving contact is constructed of platinum.

36. The sealed micro-electromechanical system switch as claimed in claim 33, wherein said fixed contact is constructed of tungsten.

37. The sealed micro-electromechanical system switch as claimed in claim 33, wherein said gap is less than 100 nm.

38. The sealed micro-electromechanical system switch as claimed in claim 33, wherein said gap is 1 to 30 nm.

39. The sealed micro-electromechanical system switch as claimed in claim 33, wherein said fixed contact includes an anti-stick layer formed thereon.

40. The sealed micro-electromechanical system switch as claimed in claim 39, wherein said anti-stick layer is constructed of a silicon dioxide monolayer.

41. The sealed micro-electromechanical system switch as claimed in claim 39, wherein said anti-stick layer is constructed of a monolayer layer of carbon.

42. The sealed micro-electromechanical system switch as claimed in claim 39, wherein said anti-stick layer is constructed of a monolayer layer of oxygen.

43. The sealed micro-electromechanical system switch as claimed in claim 39, wherein an effective gap of less than 1 nm is formed by said anti-stick layer.

44. The sealed micro-electromechanical system switch as claimed in claim 39, wherein an effective gap is formed by said anti-stick layer;

said effective gap substantially preventing metal atoms in said second contact from physically contacting metal atoms in said first contact.

45. The sealed micro-electromechanical system switch as claimed in claim 33, wherein said metal plug includes an anti-stick layer formed said second end of said metal plug.

46. The sealed micro-electromechanical system switch as claimed in claim 45, wherein said anti-stick layer is constructed of a silicon dioxide monolayer.

47. The sealed micro-electromechanical system switch as claimed in claim 45, wherein said anti-stick layer is constructed of a monolayer layer of carbon.

48. The sealed micro-electromechanical system switch as claimed in claim 45, wherein said anti-stick layer is constructed of a monolayer layer of oxygen.

49. The sealed micro-electromechanical system switch as claimed in claim 45, wherein an effective gap of less than 1 nm is formed by said anti-stick layer.

50. The sealed micro-electromechanical system switch as claimed in claim 45, wherein an effective gap is formed by said anti-stick layer;

said effective gap substantially preventing metal atoms in said second contact from physically contacting metal atoms in said first contact.

51. A micro-electromechanical system tunneling transistor switch, comprising:

a P-type silicon substrate;

a fixed contact embedded in said P-type silicon substrate;

a moving contact;

an actuating electrode embedded in said P-type silicon substrate;

a voltage source to apply a voltage to said actuating electrode so as to cause said silicon moving contact to move to provide an electrical engagement between said fixed contact and said moving contact.

52. The micro-electromechanical system tunneling transistor switch as claimed in claim 51, wherein said fixed contact includes an anti-stick layer formed thereon.

53. The micro-electromechanical system switch as claimed in claim 52, wherein an effective gap of less than 1 nm is formed by said anti-stick layer.

54. The micro-electromechanical system switch as claimed in claim 52, wherein an effective gap is formed by said anti-stick layer;

said effective gap substantially preventing metal atoms in said second contact from physically contacting metal atoms in said first contact.

55. The micro-electromechanical system tunneling transistor switch as claimed in claim 52, wherein said anti-stick layer is constructed of a silicon dioxide monolayer.

56. The micro-electromechanical system tunneling transistor switch as claimed in claim 52, wherein said anti-stick layer is constructed of a monolayer layer of carbon.

57. The micro-electromechanical system tunneling transistor switch as claimed in claim 52, wherein said anti-stick layer is constructed of a monolayer layer of oxygen.

58. The micro-electromechanical system tunneling transistor switch as claimed in claim 51, wherein said moving contact includes an anti-stick layer formed thereon.

59. The micro-electromechanical system switch as claimed in claim 58, wherein an effective gap of less than 1 nm is formed by said anti-stick layer.

60. The micro-electromechanical system switch as claimed in claim 58, wherein an effective gap is formed by said anti-stick layer;

said effective gap substantially preventing metal atoms in said second contact from physically contacting metal atoms in said first contact.

61. The micro-electromechanical system tunneling transistor switch as claimed in claim 58, wherein said anti-stick layer is constructed of a silicon dioxide monolayer.

62. The micro-electromechanical system tunneling transistor switch as claimed in claim 58, wherein said anti-stick layer is constructed of a monolayer layer of carbon.

63. The micro-electromechanical system tunneling transistor switch as claimed in claim 58, wherein said anti-stick layer is constructed of a monolayer layer of oxygen.

64. The micro-electromechanical system tunneling transistor switch as claimed in claim 51, further comprising a pull up electrode.

65. The micro-electromechanical system tunneling transistor switch as claimed in claim 51, wherein said moving contact is constructed of silicon and said fixed contact is constructed of n+ doped silicon.

66. The micro-electromechanical system tunneling transistor switch as claimed in claim 51, wherein said moving contact is constructed of poly-silicon and said fixed contact is constructed of n+ doped silicon.

67. The micro-electromechanical system tunneling transistor switch as claimed in claim 51, wherein said moving contact is constructed of SOI and said fixed contact is constructed of n+ doped silicon.

68. The micro-electromechanical system tunneling transistor switch as claimed in claim 51, wherein said moving contact is constructed of ruthenium oxide and said fixed contact is constructed of rhodium.

69. A micro-electromechanical system tunneling triode switch, comprising:

a silicon substrate;

a fixed contact embedded in said silicon substrate;

a moving beam anchored at one end;

actuating electrodes embedded in said silicon substrate;

a first stop located on a first side of said fixed contact;

a second stop located on a second side of said fixed contact; and

a voltage source to apply a voltage to said actuating electrodes so as to cause said moving beam to move to provide an electrical engagement between said fixed contact and said moving beam.

70. The micro-electromechanical system tunneling triode switch as claimed in claim 69, wherein said fixed contact includes an anti-stick layer formed thereon.

71. The micro-electromechanical system switch as claimed in claim 70, wherein an effective gap of less than 1 nm is formed by said anti-stick layer.

72. The micro-electromechanical system switch as claimed in claim 70, wherein an effective gap is formed by said anti-stick layer;

said effective gap substantially preventing metal atoms in said second contact from physically contacting metal atoms in said first contact.

73. The micro-electromechanical system tunneling triode switch as claimed in claim 70, wherein said anti-stick layer is constructed of a silicon dioxide monolayer.

74. The micro-electromechanical system tunneling triode switch as claimed in claim 70, wherein said anti-stick layer is constructed of a monolayer layer of carbon.

75. The micro-electromechanical system tunneling triode switch as claimed in claim 70, wherein said anti-stick layer is constructed of a monolayer layer of oxygen.

76. The micro-electromechanical system tunneling triode switch as claimed in claim 69, wherein said moving beam includes an anti-stick layer formed thereon.

77. The micro-electromechanical system switch as claimed in claim 76, wherein an effective gap of less than 1 nm is formed by said anti-stick layer.

78. The micro-electromechanical system switch as claimed in claim 76, wherein an effective gap is formed by said anti-stick layer;

said effective gap substantially preventing metal atoms in said second contact from physically contacting metal atoms in said first contact.

79. The micro-electromechanical system tunneling triode switch as claimed in claim 76, wherein said anti-stick layer is constructed of a silicon dioxide monolayer.

80. The micro-electromechanical system tunneling triode switch as claimed in claim 76, wherein said anti-stick layer is constructed of a monolayer layer of carbon.

81. The micro-electromechanical system tunneling triode switch as claimed in claim 76, wherein said anti-stick layer is constructed of a monolayer layer of oxygen.

82. The micro-electromechanical system tunneling triode switch as claimed in claim 69, wherein said moving beam is constructed of platinum and said fixed contact is constructed of platinum.

83. The micro-electromechanical system tunneling triode switch as claimed in claim 69, wherein said moving beam is anchored at each end.

84. A switch comprising:

a first contact; and

a second contact;

said first and said second contact having a gap therebetween which is less than 50 nm when said first and second contacts provide an open switch.

85. A micro-electromechanical system switch, comprising:

a substrate;

a plurality of actuating electrodes formed said substrate, each actuating electrode being activatable;

a cantilever beam having a first end and a second end;

a plurality of stops formed on said substrate to engage said cantilever beam between said plurality of actuating electrodes; and

a contact area formed in said substrate and located to engage said second end of said cantilever beam.

86. The micro-electromechanical system switch as claimed in claim 85, further comprising a voltage source to apply a voltage to each actuating electrode independently in a sequence from an actuating electrode located adjacent to said first end of said cantilever beam to an actuating electrode located adjacent to said second end of said cantilever beam so that said plurality of stops sequentially engage said substrate between said plurality of actuating electrodes.

87. The micro-electromechanical system switch as claimed in claim 86, wherein a gap is formed between a second end of said cantilever beam and said contact area when all actuating electrodes, but the actuating electrode located adjacent to said second end of said cantilever beam, have been actuated.

88. The micro-electromechanical system switch as claimed in claim 87, wherein said gap is less than 100 nm.

89. The micro-electromechanical system switch as claimed in claim 87, wherein said gap is 1 to 30 nm.

90. The micro-electromechanical system switch as claimed in claim 86, wherein an effective gap is formed between a second end of said cantilever beam and said contact area when all actuating electrodes have been actuated.

91. The micro-electromechanical system switch as claimed in claim 90, wherein said effective gap is less than 1 nm.

92. The micro-electromechanical system switch as claimed in claim 90, wherein said effective gap substantially prevents metal atoms in said second end of said cantilever from physically contacting metal atoms in said contact area.

93. The micro-electromechanical system switch as claimed in claim 85, further comprising a voltage source to apply a voltage to each actuating electrode independently in a sequence from an actuating electrode located adjacent to said first end of said cantilever beam to an actuating electrode located adjacent to said second end of said cantilever beam so that the micro-electromechanical system switch closes in stages.

94. The micro-electromechanical system switch as claimed in claim 85, wherein said cantilever beam is a multi-metal cantilever beam.

95. The micro-electromechanical system switch as claimed in claim 85, wherein said cantilever beam is constructed of a first layer of titanium formed upon a second layer of aluminum, which is formed upon a third layer of titanium.

96. The micro-electromechanical system switch as claimed in claim 85, wherein said cantilever beam is constructed of a first layer of titanium formed upon a second layer of tungsten, which is formed upon a third layer of titanium.

97. The micro-electromechanical system switch as claimed in claim 85, wherein said plurality of stops is constructed of platinum.

98. The micro-electromechanical system switch as claimed in claim 85, wherein said contact area includes an anti-stick layer formed thereon.

99. The micro-electromechanical system switch as claimed in claim 98, wherein said anti-stick layer is constructed of a silicon dioxide monolayer.

100. The micro-electromechanical system switch as claimed in claim 98, wherein said anti-stick layer is constructed of a monolayer layer of carbon.

101. The micro-electromechanical system switch as claimed in claim 98, wherein said anti-stick layer is constructed of a monolayer layer of oxygen.

102. The micro-electromechanical system switch as claimed in claim 85, wherein said cantilever beam includes strain relieving slits.

103. The micro-electromechanical system switch as claimed in claim 85, wherein said first end of said cantilever beam is thinner than said second end of said cantilever beam.

104. The micro-electromechanical system switch as claimed in claim 85, wherein a thickness of said cantilever beam increase from said first end of said cantilever beam to said second end of said cantilever beam.

105. A micro-electromechanical system switch, comprising:

a substrate;

an actuating electrode formed said substrate;

a cantilever beam having a first end and a second end;

a plurality of stops formed on said substrate to engage said cantilever beam; and

a contact area formed in said substrate and located to engage said second end of said cantilever beam.

106. The micro-electromechanical system switch as claimed in claim 105, wherein a gap is formed between a second end of said cantilever beam and said contact area, said gap being less than 100 nm.

107. The micro-electromechanical system switch as claimed in claim 105, wherein a gap is formed between a second end of said cantilever beam and said contact area, said gap being 1 to 30 nm.

108. The micro-electromechanical system switch as claimed in claim 105, wherein an effective gap is formed between a second end of said cantilever beam and said contact area when said actuating electrode has been actuated.

109. The micro-electromechanical system switch as claimed in claim 108, wherein said effective gap is less than 1 nm.

110. The micro-electromechanical system switch as claimed in claim 108, wherein said effective gap substantially prevents metal atoms in said second end of said cantilever from physically contacting metal atoms in said contact area.

111. The micro-electromechanical system switch as claimed in claim 105, wherein said cantilever beam is a multi-metal cantilever beam.

112. The micro-electromechanical system switch as claimed in claim 105, wherein said cantilever beam is constructed of a first layer of titanium formed upon a second layer of aluminum, which is formed upon a third layer of titanium.

113. The micro-electromechanical system switch as claimed in claim 105, wherein said cantilever beam is constructed of a first layer of titanium formed upon a second layer of tungsten, which is formed upon a third layer of titanium.

114. The micro-electromechanical system switch as claimed in claim 105, wherein said plurality of stops is constructed of platinum.

115. The micro-electromechanical system switch as claimed in claim 105, wherein said contact area includes an anti-stick layer formed thereon.

116. The micro-electromechanical system switch as claimed in claim 115, wherein said anti-stick layer is constructed of a silicon dioxide monolayer.

117. The micro-electromechanical system switch as claimed in claim 115, wherein said anti-stick layer is constructed of a monolayer layer of carbon.

118. The micro-electromechanical system switch as claimed in claim 115, wherein said anti-stick layer is constructed of a monolayer layer of oxygen.

119. The micro-electromechanical system switch as claimed in claim 105, wherein said cantilever beam includes strain relieving slits.

120. The micro-electromechanical system switch as claimed in claim 105, wherein said first end of said cantilever beam is thinner than said second end of said cantilever beam.

121. The micro-electromechanical system switch as claimed in claim 105, wherein a thickness of said cantilever beam increase from said first end of said cantilever beam to said second end of said cantilever beam.

122. A micro-electromechanical system switch, comprising:

a substrate;

an actuating electrode formed said substrate;

a cantilever beam having a first end and a second end;

a plurality of stops formed on said cantilever beam to engage said substrate; and

a contact area formed in said substrate and located to engage said second end of said cantilever beam.

123. The micro-electromechanical system switch as claimed in claim 122, wherein a gap is formed between a second end of said cantilever beam and said contact area, said gap being less than 100 nm.

124. The micro-electromechanical system switch as claimed in claim 122, wherein a gap is formed between a second end of said cantilever beam and said contact area, said gap being 1 to 30 nm.

125. The micro-electromechanical system switch as claimed in claim 122, wherein an effective gap is formed between a second end of said cantilever beam and said contact area when said actuating electrode has been actuated.

126. The micro-electromechanical system switch as claimed in claim 125, wherein said effective gap is less than 1 nm.

127. The micro-electromechanical system switch as claimed in claim 125, wherein said effective gap substantially prevents metal atoms in said second end of said cantilever from physically contacting metal atoms in said contact area.

128. The micro-electromechanical system switch as claimed in claim 122, wherein said cantilever beam is a multi-metal cantilever beam.

129. The micro-electromechanical system switch as claimed in claim 122, wherein said cantilever beam is constructed of a first layer of titanium formed upon a second layer of aluminum, which is formed upon a third layer of titanium.

130. The micro-electromechanical system switch as claimed in claim 122, wherein said cantilever beam is constructed of a first layer of titanium formed upon a second layer of tungsten, which is formed upon a third layer of titanium.

131. The micro-electromechanical system switch as claimed in claim 122, wherein said plurality of stops is constructed of platinum.

132. The micro-electromechanical system switch as claimed in claim 122, wherein said contact area includes an anti-stick layer formed thereon.

133. The micro-electromechanical system switch as claimed in claim 132, wherein said anti-stick layer is constructed of a silicon dioxide monolayer.

134. The micro-electromechanical system switch as claimed in claim 132, wherein said anti-stick layer is constructed of a monolayer layer of carbon.

135. The micro-electromechanical system switch as claimed in claim 132, wherein said anti-stick layer is constructed of a monolayer layer of oxygen.

136. The micro-electromechanical system switch as claimed in claim 122, wherein said cantilever beam includes strain relieving slits.

137. The micro-electromechanical system switch as claimed in claim 122, wherein said first end of said cantilever beam is thinner than said second end of said cantilever beam.

138. The micro-electromechanical system switch as claimed in claim 122, wherein a thickness of said cantilever beam increase from said first end of said cantilever beam to said second end of said cantilever beam.