Systems and methods for separating components of a multilayer stack of electronic components

• US 8,748,324 B1
• Filed: 02/26/2013
• Issued: 06/10/2014
• Est. Priority Date: 02/26/2013
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Zhang, Xiaobo, Fetzer, Christopher M., Rehder, Eric M., Woo, Robyn L.
• Primary Examiner(s): PERT, EVAN T
• Application Number:
  US13/777,334
• Time in Patent Office: 469 Days
• Field of Search: 204/242, 204/279, 204/280, 361/500, 438/57, 438/746
• US Class Current: 438/746
• CPC Class Codes: C25F 5/00 Electrolytic stripping of metallic layers or coatings
• CPC Class Codes: H01L 21/77 Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate electrically programmable read-only memories or multistep manufacturing processes therefor H10B69/00
• CPC Class Codes: H01L 21/7806 involving the separation of the active layers from a substrate
• CPC Class Codes: H01L 21/7813 leaving a reusable substrate, e.g. epitaxial lift off
• CPC Class Codes: H01L 31/06875 inverted grown metamorphic [IMM] multiple junction solar cells, e.g. III-V compounds inverted metamorphic multi-junction cells
• CPC Class Codes: H01L 31/1892 methods involving the use of temporary, removable substrates
• CPC Class Codes: Y02E 10/544 Solar cells from Group III-V materials

Abstract

Systems and methods for separating components of a multilayer stack of electronic components. The multilayer stack includes an electronic assembly, a substrate, and a sacrificial anode portion that is located between the electronic assembly and the substrate and that operatively attaches the electronic assembly to the substrate. The systems and methods may include locating the multilayer stack within an electrically conductive fluid to form an electrochemical cell. The systems and methods further may include generating a potential difference between a cathode portion of the electronic assembly and the sacrificial anode portion such that the cathode portion forms a cathode of the electrochemical cell and the sacrificial anode portion forms an anode of the electrochemical cell. The systems and methods additionally may include separating the electronic assembly from the substrate by electrochemically oxidizing the sacrificial anode portion to dissolve the sacrificial anode portion within the electrically conductive solution.

Claims

1. A method of separating an electronic assembly from a multilayer stack of electronic components that includes the electronic assembly, a substrate, and a sacrificial anode portion that is located between the electronic assembly and the substrate and that operatively attaches the electronic assembly to the substrate, wherein the electronic assembly includes a cathode portion and a device portion, the method comprising:

locating the multilayer stack within an electrically conductive fluid to form an electrochemical cell;

generating a potential difference between the cathode portion and the sacrificial anode portion such that the cathode portion forms a cathode of the electrochemical cell and the sacrificial anode portion forms an anode of the electrochemical cell; and

separating the electronic assembly from the substrate by electrochemically oxidizing the sacrificial anode portion to dissolve the sacrificial anode portion within the electrically conductive fluid.

2. The method of claim 1, wherein the electronic assembly further includes a sacrificial photovoltaic cell that is located between and in electrical and mechanical communication with the cathode portion and the sacrificial anode portion, and further wherein the generating includes:

generating the potential difference with the sacrificial photovoltaic cell.

3. The method of claim 2, further comprising:

directing electromagnetic radiation onto the sacrificial photovoltaic cell to initiate the generating.

4. The method of claim 1, further comprising:

establishing a first electrical connection between the cathode portion and a positive terminal of an external power source; and

establishing a second electrical connection between the sacrificial anode portion and a negative terminal of the external power source, wherein the generating includes generating the potential difference with the external power source.

5. The method of claim 1, wherein the multilayer stack is a first multilayer stack, wherein the electronic assembly is a first electronic assembly of the first multilayer stack, wherein the sacrificial anode portion is a first sacrificial anode portion of the first multilayer stack, and further wherein, subsequent to the separating, the method further comprises:

forming a second multilayer stack that includes a second electronic assembly, the substrate, and a second sacrificial anode portion that is located between the second electronic assembly and the substrate and that operatively attaches the second electronic assembly to the substrate.

6. The method of claim 5, wherein the method further comprises:

repeating at least the locating, the generating, and the separating to separate the second electronic assembly from the substrate.

7. The method of claim 1, further comprising:

selecting a magnitude of the potential difference based, at least in part, on a chemical composition of at least one of the cathode portion, the anode portion, and the electrically conductive fluid.

8. The method of claim 1, wherein the generating a potential difference includes generating a potential difference that is at least 0.1 Volts (V) and less than 5 V.

9. The method of claim 1, wherein the cathode portion and the electrically conductive fluid define a first half-cell that defines a first half-cell voltage, wherein the sacrificial anode portion and the electrically conductive fluid define a second half-cell that defines a second half-cell voltage, and further wherein the generating a potential difference includes generating a potential difference that is greater than a difference between the first half-cell voltage and the second half-cell voltage.

10. The method of claim 1, wherein the electrically conductive fluid includes at least one of an electrolyte solution, a salt solution, and a dilute salt solution.

11. A multilayer stack of electronic materials, comprising:

a substrate;

a sacrificial anode portion; and

an electronic assembly wherein the sacrificial anode portion is located between the electronic assembly and the substrate and operatively attaches the electronic assembly to the substrate, and further wherein the electronic assembly includes;

a sacrificial photovoltaic cell that is in electrical communication with the sacrificial anode portion;

a cathode portion that is in electrical communication with the sacrificial photovoltaic cell, wherein the sacrificial photovoltaic cell electrically separates the cathode portion from the sacrificial anode portion; and

a device portion, wherein the sacrificial photovoltaic cell is located between the substrate and the device portion.

12. The multilayer stack of claim 11, further comprising:

an etch stop portion that is located between the sacrificial photovoltaic cell and the device portion and operatively attaches the sacrificial photovoltaic cell to the device portion.

13. The multilayer stack of claim 12, wherein the etch stop portion includes an epitaxial etch stop layer.

14. The multilayer stack of claim 11, wherein the substrate includes at least one of a semiconductor material, a semiconductor wafer, Silicon, Germanium, a III-V semiconductor material, Indium Phosphide, and Gallium Arsenide.

15. The multilayer stack of claim 11, wherein the sacrificial anode portion is an epitaxial sacrificial anode layer.

16. The multilayer stack of claim 11, wherein the sacrificial photovoltaic cell is configured to receive electromagnetic radiation and to generate a potential difference between the sacrificial anode portion and the cathode portion responsive to receipt of the electromagnetic radiation, and further wherein a magnitude of the potential difference is at least 0.1 Volts (V) and less than 5 V.

17. The multilayer stack of claim 11, wherein the sacrificial photovoltaic cell includes an epitaxial sacrificial photovoltaic cell.

18. The multilayer stack of claim 11, wherein the device portion includes at least one of a device layer, a semiconductor device, a III-V semiconductor device, a photovoltaic cell, an inverted photovoltaic cell, and an inverted metamorphic solar cell.

19. An electrochemical cell, comprising:

an electrically conductive fluid; and

the multilayer stack of claim 11, wherein the multilayer stack is located within the electrically conductive fluid.

20. The electrochemical cell of claim 19 in combination with a source of electromagnetic radiation, wherein the source of electromagnetic radiation is oriented to direct the electromagnetic radiation onto the sacrificial photovoltaic cell, wherein at least one of a wavelength of the electromagnetic radiation and an intensity of the electromagnetic radiation is selected such that the sacrificial photovoltaic cell generates a potential difference between the cathode portion and the sacrificial anode portion, wherein the potential difference produces dissolution of the sacrificial anode portion within the electrically conductive fluid, and further wherein a portion of the sacrificial anode portion is dissolved within the electrically conductive fluid.