Processes for lift-off of thin film materials or devices for fabricating three dimensional integrated circuits, optical detectors, and micromechanical devices

• US 5,401,983 A
• Filed: 04/07/1993
• Issued: 03/28/1995
• Est. Priority Date: 04/08/1992
• Status: Expired due to Fees

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Jokerst, Nan M., Brooke, Martin A., Allen, Mark G.
• Primary Examiner(s): MINTEL, WILLIAM A
• Application Number:
  US08/044,251
• Time in Patent Office: 720 Days
• Field of Search: 257/82, 257/85, 257/98, 257/443, 257/84, 372/50, 437/915, 437/944
• US Class Current: 257/82
• CPC Class Codes: B81C 1/00373 Selective deposition, e.g. printing or microcontact printing
• CPC Class Codes: B81C 2201/0188 Selective deposition techniques not provided for in B81C2201/0184 - B81C2201/0187
• CPC Class Codes: B81C 2201/0194 the layer being structured
• CPC Class Codes: H01L 21/2007 Bonding of semiconductor wafers to insulating substrates or to semiconducting substrates using an intermediate insulating layer H01L21/2011 takes precedence; bonding of semiconductor wafers to semiconductor wafers for junction formation H01L21/187
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: H01L 2221/68368 used in a transfer process involving at least two transfer steps, i.e. including an intermediate handle substrate
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/14687 Wafer level processing
• CPC Class Codes: H01L 27/14694 The active layers comprising only AIIIBV compounds, e.g. GaAs, InP
• CPC Class Codes: H01L 33/0062 for devices with an active region comprising only III-V compounds
• CPC Class Codes: H01S 5/0215 Bonding to the substrate
• CPC Class Codes: H01S 5/0217 Removal of the substrate
• CPC Class Codes: H01S 5/183 having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]

Abstract

Various novel lift-off and bonding processes (60, 80, 100) permit lift-off of thin film materials and devices (68), comprising In_x Ga_1-x As_y P_1-y where 0<x<1, and 0<y<1, from a growth substrate (62) and then subsequent alignable bonding of the same to a host substrate (84). As a result, high quality communication devices can be fabricated for implementing a three dimensional electromagnetic communication network within a three dimensional integrated circuit cube (10), an array (90) of optical detectors (98) for processing images at very high speed, and a micromechanical device (110) having a platform (114) for steering or sensing electromagnetic radiation or light.

Claims

1. A micromechanical device for providing efficient steerable optical coupling with integrated circuitry, comprising:

a movable platform supported by legs on a substrate, said substrate having a substrate electrode, said platform having a bottom electrode, and wherein said platform is moved by applying a first electrical source between said substrate electrode and said bottom electrode; and

a photonic device residing on said platform and movable therewith, said photonic device being created on a growth substrate remote from said movable platform and subsequently bonded to said movable platform, said photonic device having a top electrode thereon, said photonic device serving as a light interface when a second electrical source is applied between said top electrode and said bottom electrode.

3. The micromechanical device of claim 1, wherein said photonic device is created on a growth substrate remote from said movable platform and is subsequently placed onto said movable platform.

4. The micromechanical device of claim 1, wherein said photonic device is created and disposed on said platform by the following steps:

depositing said photonic device onto a sacrificial layer situated on a growth substrate;

coating said photonic device with a carrier layer;

removing said sacrificial layer to release the combination of said photonic device and said carrier layer from said growth substrate;

positioning said photonic device on a transfer medium;

removing said carrier layer; and

bonding said photonic device to said platform from said transfer medium.

5. The micromechanical device of claim 1, wherein said photonic device comprises thin film semiconductor layers.

6. The micromechanical device of claim 1, wherein said photonic device comprises In_x Ga_1-x As_y P_1-y where 0<

x<

1 and 0<

y<

1.

7. The micromechanical device of claim 1, wherein said substrate comprises silicon and wherein said photonic device comprises In_x Ga_1-x As_y P_1-y where 0<

x<

1 and 0<

y<

1.

8. The micromechanical device of claim 1, wherein said legs of said movable platform comprise polyimide.

9. The micromechanical device of claim 1, wherein said movable platform comprises a rectangular platform surface supported by legs at corners of the rectangular surface.

10. The micromechanical device of claim 1, wherein said photonic device is a resonant cavity device.

11. The micromechanical device of claim 9, further comprising a plurality of bottom electrodes situated on said substrate and capable of receiving charge from said first electrical source, whereby said bottom electrodes are selectively activated by said first electrical source so that said platform is selectively moved as the electric field between said bottom electrodes and said substrate electrode is changed.

21. The micromechanical device of claim 1, wherein said moveable platform comprises a generally square platform surface supported by legs at corners of said platform surface.

22. The micromechanical device of claim 1, wherein said substrate electrode comprises gold.

23. The micromechanical device of claim 1, wherein said bottom electrode comprises AuZn/Au.

24. The micromechanical device of claim 1, wherein said photonic device emits a signal.

25. The micromechanical device of claim 1, wherein said photonic device detects a signal.

26. The micromechanical device of claim 1, wherein said photonic device modulates a signal.

27. The micromechanical device of claim 4, wherein said sacrificial layer is AlAs.

28. The micromechanical device of claim 4, wherein said growth substrate is GaAs.

29. The micromechanical device of claim 4, wherein said carrier layer is Apiezon W black wax.

30. The micromechanical device of claim 4, wherein said sacrificial layer is removed by immersion in 10% HF.

31. The micromechanical device of claim 5, wherein said thin film semiconductor layers comprise a crystalline material.

32. The micromechanical device of claim 21, wherein said platform surface measures 360 micrometers by 360 micrometers and said legs have a width of 20 micrometers.

33. The micromechanical device of claim 21, wherein said square platform surface measures 200 micrometers by 200 micrometers and wherein said legs have a width of 40 micrometers.

34. The micromechanical device of claim 32, wherein said photonic device measures 250 micrometers by 250 micrometers.

35. The micromechanical device of claim 33, wherein said photonic device measures 100 micrometers by 100 micrometers.

2. A resonant cavity device, comprising:

an active region having a first side and a second side;

a first mirror layer situated adjacent to said first side, said first mirror layer being deposited after said active region is deposited on a first substrate; and

a second mirror layer situated adjacent to said second side, said second mirror layer being deposited after the combination of said active region and said first mirror layer are bonded to a second substrate.

13. The resonant cavity device of claim 2, wherein said active region comprises a diode configuration.

14. The resonant cavity device of claim 2, wherein said first mirror layer comprises In_x Ga_1-x As_y P_1-y where 0<

x<

1 and 0<

y<

1.

15. The resonant cavity device of claim 2, wherein said second mirror layer comprises In_x Ga_1-x As_y P_1-y where 0<

x<

1 and 0<

y<

1.

16. The resonant cavity device of claim 2, further comprising first and second metal layers disposed on said first and second mirror layers respectively and situated at opposing outer ends of said resonant cavity device.

17. The resonant cavity device of claim 2, wherein said active region emits a signal.

18. The resonant cavity device of claim 2, wherein said active region detects a signal.

19. The resonant cavity device of claim 2, wherein said active region modulates a signal.

12. A micromechanical device for interfacing light with an electronic circuit, comprising:

a platform supported by legs on a substrate;

means for moving said platform; and

a photonic device residing on said platform and movable with said platform, said photonic device connected to a circuit and serving as a light interface to said circuit, said photonic device being created on a growth substrate remote from said movable platform and subsequently bonded to said movable platform.

20. A resonant cavity configuration, comprising:

a host substrate; and

a resonant cavity device bonded to said host substrate, said resonant cavity device comprising an active region having a first side and a second side, a first mirror layer situated adjacent to said first side, and a second mirror layer situated adjacent to said second side, said active region and said first mirror layer being formed on a remote growth substrate and subsequently bonded to said host substrate, said second mirror layer being formed on said active region after the combination of said active region and said first mirror layer are deposited on said host substrate.