Method and apparatus for fabricating self-assembling microstructures

• US 6,864,570 B2
• Filed: 06/08/2001
• Issued: 03/08/2005
• Est. Priority Date: 12/17/1993
• Status: Expired due to Fees

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Smith, John Stephen
• Primary Examiner(s): Tran, Minhloan
• Assistant Examiner(s): Dickey, Thomas L
• Application Number:
  US09/877,640
• Publication Number:
  US 20010031514A1
• Time in Patent Office: 1,369 Days
• Field of Search: 257/701, 257/702, 257/707, 257/723, 257/724, 257/730, 257/752, 257/786, 257/E21.705, 257/E25.013
• US Class Current: 257/703
• CPC Class Codes: G02F 1/136 Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit G02F1/135 takes precedence
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 21/02002 Preparing wafers
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2221/68359 used as a support during manufacture of interconnect decals or build up layers
• CPC Class Codes: H01L 2224/24227 the HDI interconnect not connecting to the same level of the item at which the semiconductor or solid-state body is mounted, e.g. the semiconductor or solid-state body being mounted in a cavity or on a protrusion of the item
• CPC Class Codes: H01L 2224/83136 involving guiding structures, e.g. spacers or supporting members
• CPC Class Codes: H01L 2224/8319 Arrangement of the layer connectors prior to mounting
• CPC Class Codes: H01L 2224/8385 using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 2224/95085 being a liquid, e.g. for fluidic self-assembly
• CPC Class Codes: H01L 2224/95092 Atmospheric pressure, e.g. dry self-assembly
• CPC Class Codes: H01L 2224/95122 by applying vibration
• CPC Class Codes: H01L 2224/95136 involving guiding structures, e.g. shape matching, spacers or supporting members
• CPC Class Codes: H01L 23/13 characterised by the shape
• CPC Class Codes: H01L 23/147 Semiconductor insulating substrates semiconductor conductive substrates H01L23/4926
• CPC Class Codes: H01L 24/24 of an individual high density interconnect connector
• CPC Class Codes: H01L 24/26 Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
• CPC Class Codes: H01L 24/82 by forming build-up interconnects at chip-level, e.g. for high density interconnects [HDI] interconnection structure between a plurality of semiconductor chips H01L23/5389
• CPC Class Codes: H01L 24/83 using a layer connector
• CPC Class Codes: H01L 24/95 : at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips
• CPC Class Codes: H01L 25/0655 : the devices being arranged next to each other
• CPC Class Codes: H01L 25/50 : Multistep manufacturing processes of assemblies consisting of devices, each device being of a type provided for in group H01L27/00 or H01L29/00 H01L21/50 takes precedence
• CPC Class Codes: H01L 29/0657 : characterised by the shape of the body
• 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 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01018 : Argon [Ar]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/0102 : Calcium [Ca]
• CPC Class Codes: H01L 2924/01023 : Vanadium [V]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01032 : Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/01072 : Hafnium [Hf]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/07802 : not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/10158 : at the passive surface
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/10329 : Gallium arsenide [GaAs]
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15153 : the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/15155 : the shape of the recess being other than a cuboid
• CPC Class Codes: H01L 2924/15157 : Top view
• CPC Class Codes: H01L 2924/15165 : Monolayer substrate
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/15788 : Glasses, e.g. amorphous oxides, nitrides or fluorides
• CPC Class Codes: H01L 2924/30105 : Capacitance
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H01L 2924/3512 : Cracking
• CPC Class Codes: Y10S 438/978 : forming tapered edges on substrate or adjacent layers

Abstract

A method and apparatus for assembling microstructures onto a substrate through fluid transport. The microstructures being shaped blocks self-align into recessed regions located on a substrate such that the microstructure becomes integral with the substrate. The improved method includes a step of transferring the shaped blocks into a fluid to create a slurry. Such slurry is then dispensed evenly or circulated over the top surface of a substrate having recessed regions thereon. The microstructure via the shape and fluid tumbles onto the surface of the substrate, self-aligns, and engages into a recessed region.

Claims

1. A structure comprising an assemblage of separate electronic devices, each electronic device having a first surface and a second surface substantially parallel to said first surface, said electronic device further having a beveled side connecting said first surface to said second surface, said first surface having a smaller area than said second surface, said electronic device further having electronic structures formed on said second surface.

2. The structure of claim 1 wherein said electronic device has a length dimension of about 50 microns or less.

3. The structure of claim 1 wherein said electronic device has a trapezoidal cross-section.

4. The structure of claim 1 wherein said side surfaces are etched surfaces.

5. The structure of claim 1 wherein said electronic device is a multilayered structure.

6. The structure of claim 5 wherein said multilayered structure includes a metal layer.

7. The structure of claim 5 wherein said multilayered structure includes an insulator layer.

8. The structure of claim 5 wherein said multilayered structure includes a layer of silicon dioxide.

9. The structure of claim 5 wherein said multilayered structure includes a layer of silicon nitride.

10. The structure of claim 1 wherein said electronic device comprises material is selected from the group consisting of silicon, gallium arsenide, aluminum gallium arsenide, diamond, and germanium.

11. The structure of claim 1 wherein said electronic device comprises a group III-V compound.

12. The structure of claim 1 wherein the perimeter of said first surface has a rectangular shape, an octagonal shape, or a circular shape.

13. The structure of claim 1 wherein said electronic device has a length dimension of about 1 mm or less.

14. The structure of claim 1 wherein said electronic device has a length dimension of about 500 microns or less.

15. The structure of claim 1 wherein said electronic device has an edge portion that is beveled.

16. The structure of claim 1 wherein said electronic device is shaped like a truncated pyramid.

17. A shaped block of material adapted for being received in a recess of a substrate, said shaped block of material having sloped sides and a top surface connected to a bottom surface by said sloped sides, said top surface being substantially parallel to said bottom surface, said top surface being non-congruent with said bottom surface, a larger of said top surface and bottom surface having formed thereon an electronic device.

18. The shaped block of claim 17 wherein said block of material has a length measurement less than or equal to 50 microns.

19. The shaped block of claim 17 wherein said sloped sides are etched sides.

20. The shaped block of claim 17 wherein said sloped sides have a slope between about 40°

and 60°

relative to a line normal to said top surface.

21. The shaped block of claim 17 wherein said material comprises a multilayered structure.

22. The shaped block of claim 17 wherein said material is selected from the group consisting of silicon, gallium arsenide, aluminum gallium arsenide, diamond, and germanium.

23. The shaped block of claim 17 wherein said material comprises a group III-V compound.

24. The shaped block of claim 17 wherein the perimeter of said first surface has a rectangular shape, an octagonal shape, or a circular shape.

25. The shaped block of claim 17 wherein said block of material has a length measurement less than or equal to 500 microns.

26. The shaped block of claim 17 wherein said block of material has a length measurement less than or equal to 1 mm.

27. The shaped block of claim 17 wherein said sloped sides have a trapezoidal profile.

28. The shaped block of claim 17 wherein said sloped sides define a portion of a beveled edge.

29. The shaped block of claim 17 wherein said shaped block has a shape of a truncated pyramid.

30. A shaped functional block comprising a semiconductor material and having a shape adapted for self-alignment within a shaped recess formed through a substrate surface, said block having a first surface and a second surface and having etched sides which are sloped such that said block fits into said shaped opening only in an orientation where said first surface is exposed through said substrate surface, said first surface connected to said second surface only by said etched sides, said first surface being larger in area than said second surface and having electronic structures formed thereon.

31. The functional block of claim 30 wherein said first surface includes a conductive contact disposed thereon.

32. The functional block of claim 30 wherein said first surface has an area smaller than said second surface.

33. The functional block of claim 32 wherein said first surface has a circular perimeter, a rectilinear perimeter, or an octagonal perimeter.

34. The functional block of claim 30 having a maximum length dimension of about 1 mm or less.

35. The functional block of claim 30 further comprising a multilayered structure.

36. The functional block of claim 35 wherein said multilayered structure includes a metal layer.

37. The functional block of claim 35 wherein said multilayered structure includes an insulator layer.

38. The functional block of claim 35 wherein said multilayered structure includes a layer of silicon dioxide.

39. The functional block of claim 35 wherein said multilayered structure includes a layer of silicon nitride.

40. The functional block of claim 30 being a light-emitting diode.

41. The functional block of claim 30 having a maximum length dimension of about 500 micron or less.

42. The functional block of claim 30 having a maximum length dimension of about 50 micron or less.

43. The functional block of claim 30 wherein said etched sides are characterized by having a trapezoidal profile.

44. The functional block of claim 30 wherein said etched sides form a beveled edge adjacent said first surface.

45. The functional block of claim 30 having a shape of a truncated pyramid.

46. A semiconductor microstructure comprising a shaped block having a first surface substantially parallel to a second surface, said first surface having an associated first area, said second surface having an associated second area, said first area being larger than said second area, an edge that is adjacent both said first surface and said second surface being sloped, said first surface having formed thereon electronic structures, said block having a maximum length dimension of about 1 mm or less in measure.

47. The semiconductor microstructure of claim 46 wherein said shaped block comprises material selected from the group consisting of silicon, gallium arsenide, aluminum gallium arsenide, diamond, and germanium.

48. The semiconductor microstructure of claim 46 wherein said shaped block comprises a group III-V compound.

49. The semiconductor microstructure of claim 46 wherein said shaped block is a multilayered structure.

50. The semiconductor microstructure of claim 49 wherein said multilayered structure constitutes a light-emitting diode.

51. The semiconductor microstructure of claim 50 wherein said multilayered structure includes gallium arsenide.

52. The semiconductor microstructure of claim 46 wherein said length dimension further is about 500 microns or less in measure.

53. The semiconductor microstructure of claim 52 wherein said length dimension further is about 50 microns or less in measure.

54. The semiconductor microstructure of claim 46 wherein said edge has a trapezoidal profile.

55. The semiconductor microstructure of claim 46 wherein said edge is beveled.

56. The semiconductor microstructure of claim 46 wherein said shaped block has a truncated pyramid appearance.

57. A portion of an integrated circuit device comprising a shaped functional block, said functional block comprising a semiconductor material and having a length dimension less than or equal to 1 mm in measure, said functional block having a top surface, a bottom surface that is smaller than said top surface, and etched sides that connect said top surface with said bottom surface, said top surface having formed thereon an electronic device.

58. The portion of an integrated circuit device of claim 57 wherein said semiconductor material is a multilayered structure.

59. The portion of an integrated circuit device of claim 57 wherein said semiconductor material is selected from the group consisting of silicon, gallium arsenide, aluminum gallium arsenide, diamond, and germanium.

60. The portion of an integrated circuit device of claim 57 wherein said semiconductor material is a group III-V compound.

61. The portion of an integrated circuit device of claim 57 wherein said semiconductor material constitutes a light-emitting diode.

62. The portion of an integrated circuit device of claim 61 wherein said light-emitting diode is a gallium arsenide light-emitting diode.

63. The portion of an integrated circuit device of claim 57 wherein said length dimension further is less than or equal to 500 microns in measure.

64. The portion of an integrated circuit device of claim 63 wherein said length dimension further is less than or equal to 50 microns in measure.

65. The portion of an integrated circuit device of claim 57 wherein said etched sides have a form a trapezoidal profile.

66. The portion of an integrated circuit device of claim 57 wherein said functional block further comprises a first major surface and a second major surface connected to said first major surface by said etched sides, a portion of said etched sides adjacent to said first major surface forming a beveled edge.

67. The portion of an integrated circuit device of claim 57 wherein said functional block has a shape of a truncated pyramid.

68. An electronic chip comprising a shaped block of material separated from a substrate and having a first surface and a second surface substantially parallel to said first surface, said block further having etched side surfaces extending from said first surface to said second surface, said first surface having an a real measurement larger than an a real measurement of said second surface, said first surface having a conductive contact disposed thereon, wherein said material is semiconductor material.

69. The electronic chip of claim 68 wherein said block of material has a width of about 50 microns or less and a length of about 50 microns or less.

70. The electronic chip of claim 68 wherein said etched side surfaces have a slope relative to a line normal to said first surface between about 40°

and 60°

.

71. The electronic chip of claim 68 wherein said material comprises a multilayered structure including one or more layers of semiconductor material.

72. The electronic chip of claim 71 wherein said multilayered structure includes a p-type gallium arsenide layer, an n-type gallium arsenide layer, and a eutectic layer.

73. The electronic chip of claim 68 wherein said electronic chip is a light-emitting diode.

74. The electronic chip of claim 68 wherein said electronic chip is a gallium arsenide resonant tunneling diode.

75. The electronic chip of claim 68 wherein said electronic chip is a gallium arsenide diode.

76. The electronic chip of claim 68 wherein said electronic chip is a gallium arsenide microwave device.

77. The electronic chip of claim 68 wherein a cross-section thereof shows one of a cylindrical shape, a rectangular shape, a square shape, a hexagonal shape, a T-shape, and a kidney shape.

78. The electronic chip of claim 68 wherein said block of material has a width of about 1 mm or less and a length of about 1 mm or less.

79. The electronic chip of claim 68 wherein said block of material has a width of about 500 microns or less and a length of about 500 microns or less.

80. The electronic chip of claim 68 wherein said shaped block has an outwardly sloped profile.

81. The electronic chip of claim 68 wherein said shaped block has an inwardly sloped profile.

82. The electronic chip of claim 68 wherein a profile of said shaped block resembles a trapezoid.

83. The electronic chip of claim 68 wherein said etched side surfaces define a beveled edge adjacent said first surface.

84. The electronic chip of claim 68 wherein said shaped block is one of a pyramid shape and a truncated pyramid shape.

85. An electronic chip comprising a shaped functional block including a semiconductor material, said functional block having tapered sides connecting a top surface to a bottom surface smaller than said top surface, said top surface having formed thereon at least one electronic device, said functional block further having a length measurement less than or equal to 1 mm, a perimeter of said top surface having a rectilinear shape, a circular shape, or an octagonal shape.

86. The electronic chip of claim 85 wherein said top surface is substantially parallel to said bottom surface.

87. The electronic chip of claim 85 further including a conductive contact disposed atop either or both said top surface and said bottom surface.

88. The electronic chip of claim 85 wherein said semiconductor material is a multilayered structure.

89. The electronic chip of claim 88 wherein said multilayered structure constitutes a light-emitting diode.

90. The electronic chip of claim 85 wherein said length measurement further is less than or equal to 500 microns.

91. The electronic chip of claim 90 wherein said length measurement further is less than or equal to 50 microns.

92. The electronic chip of claim 85 wherein said tapered sides define at least a beveled edge adjacent said top surface.

93. An electronic component separated from a first substrate comprising:

a first surface;

a conductive contact disposed atop said first surface;

a second surface in substantially parallel relation to said first surface and having a smaller area than said first surface; and

etched surfaces connecting said first surface to said second surface,

said etched surfaces being tapered to define at least a beveled edge adjacent both said first surface and said second surface,

wherein said electronic component has a maximum length measurement of about 50 microns or less.

wherein said electronic component is adapted for self-alignment within a shaped opening through a surface of a second substrate.

94. The electronic component of claim 93 wherein said etched surfaces are formed by a wet etch process.

95. The electronic component of claim 93 wherein said etched surfaces are formed by a mask edge.

96. The electronic component of claim 93 wherein said etched surfaces are formed by a reactive ion etch process.

97. The electronic component of claim 93 wherein said etched surfaces are formed by an ion milling process.

98. The electronic component of claim 93 being a light-emitting diode.

99. The electronic component of claim 93 further having a maximum length measurement of about 1 mm or less.

100. The electronic component of claim 93 further having a maximum length measurement of about 500 microns or less.

101. A light-emitting diode (LED) comprising a shaped semiconductor block having tapered sides, said semiconductor block comprising a first surface and a second surface in substantially parallel relation to said first surface, said tapered sides defining at least a beveled edge adjacent both said first and second surfaces, said first surface larger in area than said second surface, said first surface having formed thereon electronic structure for producing light.

102. The LED of claim 101 wherein said semiconductor block has a length dimension less than or equal to 50 microns in measure.

103. The LED of claim 101 wherein said tapered sides are etched sides.

104. The LED of claim 101 incorporated in an active display.

105. The LED of claim 101 wherein said semiconductor block is a multilayered structure.

106. The LED of claim 105 wherein said multilayered structure includes gallium arsenide.

107. The LED of claim 105 wherein said multilayered structure includes a group III-V compound.

108. The LED of claim 101 wherein said semiconductor block has a length dimension less than or equal to 1 mm in measure.

109. The LED of claim 101 wherein said semiconductor block has a length dimension less than or equal to 500 microns in measure.

110. A light-emitting diode (LED) comprising an amount of semiconductor material, said semiconductor material having a first surface and a second surface smaller than said first surface, said semiconductor material having non-parallel side surfaces connecting said first surface to said second surface, said LED having a length dimension less than or equal to 1 mm, said first surface having formed thereon electronic structures configured to produce light.

111. The LED of claim 110 wherein said first surface is in substantially parallel relation to said second surface.

112. The LED of claim 110 wherein said semiconductor material includes a group III-V compound.

113. The LED of claim 112 wherein said semiconductor material includes gallium arsenide.

114. The LED of claim 110 wherein the perimeter of said first surface a rectangular shape, an octagonal shape, or a circular shape.

115. The LED of claim 110 wherein said length dimension further is less than or equal to 500 microns.

116. The LED of claim 115 wherein said length dimension further is less than or equal to 50 microns.

117. The LED of claim 110 further comprising a beveled edge formed adjacent one of said first and second surfaces.

118. A light-emitting diode (LED) comprising a block of semiconductor material including gallium arsenide, said block having a top surface and a bottom surface smaller in area than said top surface and connected to said top surface by sloped surfaces, said block having a length measurement of about 1 mm or less, said top surface having electronic layers formed thereon to produce light.

119. The LED of claim 118 wherein said sloped surfaces are etched surfaces.

120. The LED of claim 119 wherein said etched surfaces are formed by a wet etch process.

121. The LED of claim 119 wherein said etched surfaces are formed by a mask edge.

122. The LED of claim 119 wherein said etched surfaces are formed by a reactive ion etch process.

123. The LED of claim 119 wherein said etched surfaces are formed by an ion milling process.

124. The LED of claim 119 wherein said sloped surfaces define beveled edge adjacent one of said top and bottom surfaces.

125. The LED of claim 118 wherein the perimeter of said top surface has a rectangular shape, an octagonal shape, or a circular shape.

126. The LED of claim 118 wherein said length measurement further is about 500 microns or less.

127. The LED of claim 126 wherein said length measurement further is about 50 microns or less.

128. A shaped block of semiconductor material having tapered sides, said block of material comprising a first surface and a second surface in substantially parallel relation to said first surface and smaller in area than said first surface, said tapered sides defining a beveled edge adjacent both of said first and second surfaces, said first surface having formed thereon an electronic device.

129. The shaped block of claim 128 having a maximum length dimension less than or equal to 1 mm in measure.

130. The shaped block of claim 128 having a maximum length dimension less than or equal to 500 microns in measure.

131. The shaped block of claim 128 having a maximum length dimension less than or equal to 50 microns in measure.