Wafer-to-wafer and die-to-wafer bonding of phase-change material (PCM) switches with integrated circuits and bonded two-die devices

• US 10,566,321 B1
• Filed: 05/15/2019
• Issued: 02/18/2020
• Est. Priority Date: 08/14/2018
• Status: Active Grant

• Current Assignee: Newport Fab, LLC (Tower Semiconductor Limited)
• Original Assignee: Newport Fab, LLC (Tower Semiconductor Limited)
• Inventors: Slovin, Gregory P., Howard, David J.
• Primary Examiner(s): Seven, Evren
• Application Number:
  US16/413,509
• Publication Number:
  US 20200058628A1
• Time in Patent Office: 279 Days
• Field of Search: None
• CPC Class Codes: H01L 2224/08145 the bodies being stacked
• CPC Class Codes: H01L 2224/32145 the bodies being stacked
• CPC Class Codes: H01L 2224/80 Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
• CPC Class Codes: H01L 2224/80896 between electrically insulating surfaces, e.g. oxide or nitride layers
• CPC Class Codes: H01L 2224/83896 between electrically insulating surfaces, e.g. oxide or nitride layers
• CPC Class Codes: H01L 2224/9202 Forming additional connectors after the connecting process
• CPC Class Codes: H01L 2224/9205 Intermediate bonding steps, i.e. partial connection of the semiconductor or solid-state body during the connecting process
• CPC Class Codes: H01L 2224/94 at wafer-level, i.e. with connecting carried out on a wafer comprising a plurality of undiced individual devices
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• CPC Class Codes: H01L 24/32 of an individual layer connector
• CPC Class Codes: H01L 24/80 Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
• CPC Class Codes: H01L 24/83 using a layer connector
• CPC Class Codes: H01L 25/16 the devices being of types provided for in two or more different main groups of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. forming hybrid circuits
• 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 27/0688 Integrated circuits having a three-dimensional layout
• CPC Class Codes: H10B 63/10 Phase change RAM [PCRAM, PRAM] devices
• CPC Class Codes: H10N 70/011 Manufacture or treatment of multistable switching devices
• CPC Class Codes: H10N 70/231 based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect
• CPC Class Codes: H10N 70/823 adapted for essentially horizontal current flow, e.g. bridge type devices
• CPC Class Codes: H10N 70/8413 adapted for resistive heating
• CPC Class Codes: H10N 70/8613 : Heating or cooling means other than resistive heating electrodes, e.g. heater in parallel
• CPC Class Codes: H10N 70/8825 : Selenides, e.g. GeSe
• CPC Class Codes: H10N 70/8828 : Tellurides, e.g. GeSbTe
• CPC Class Codes: H10N 79/00 : Integrated devices, or assemblies of multiple devices, comprising at least one solid-state element covered by group H10N70/00 ReRAM devices H10B63/00; PCRAM devices H10B63/10

Abstract

In a method for wafer-to-wafer bonding, an integrated circuit (IC) wafer and a phase-change material (PCM) switch wafer are provided. The IC includes at least one active device, and has an IC substrate side and a metallization side. The PCM switch wafer has a heat spreading side and a radio frequency (RF) terminal side. A heat spreader is formed in the PCM switch wafer. In one approach, the heat spreading side of the PCM switch wafer is bonded to the metallization side of the IC wafer, then a heating element is formed between the heat spreader and a PCM in the PCM switch wafer. In another approach, a heating element is formed between the heat spreader and a PCM in the PCM switch wafer, then the RF terminal side of the PCM switch wafer is bonded to the metallization side of the IC wafer.

Claims

1. A method for wafer-to-wafer bonding, said method comprising:

providing an integrated circuit (IC) wafer including at least one active device, said IC wafer having an IC substrate side and a metallization side;

providing a phase-change material (PCM) switch wafer, said PCM switch wafer having a heat spreading side and a radio frequency (RF) terminal side;

bonding said heat spreading side of said PCM switch wafer to said metallization side of said IC wafer;

forming a heating element between a heat spreader and a PCM in said PCM switch wafer.

2. The method of claim 1, further comprising removing a substrate of said PCM switch wafer from said RF terminal side of said PCM switch wafer.

3. The method of claim 2, wherein said removing said substrate of said PCM switch wafer from said RF terminal side of said PCM switch wafer comprises etching to an etch stop layer or a buried oxide layer.

4. The method of claim 1, wherein said heat spreader is a semiconductor heat spreader comprising epitaxial silicon or bulk silicon.

15. The method of claim 1, wherein said heating element comprises a material selected from the group consisting of tungsten (W), molybdenum (Mo), titanium (Ti), titanium tungsten (TiW), titanium nitride (TiN), tantalum (Ta), tantalum nitride (TaN), nickel chromium (NiCr), and nickel chromium silicon (NiCrSi).

5. A method for wafer-to-wafer bonding, said method comprising:

providing an integrated circuit (IC) wafer including at least one active device, said IC wafer having an IC substrate side and a metallization side;

providing a phase-change material (PCM) switch wafer, said PCM switch wafer having a heat spreading side and a radio frequency (RF) terminal side;

forming a heating element between a heat spreader and a PCM in said PCM switch wafer;

bonding said RF terminal side of said PCM switch wafer to said metallization side of said IC wafer.

6. The method of claim 5, further comprising removing a substrate of said PCM switch wafer from said heat spreader side of said PCM switch wafer.

7. The method of claim 6, wherein said removing said substrate of said PCM switch wafer from said heat spreader side of said PCM switch wafer comprises etching to an etch stop layer or a buried oxide layer.

8. The method of claim 5, wherein said heat spreader is a semiconductor heat spreader comprising epitaxial silicon or bulk silicon.

16. The method of claim 5, wherein said heating element comprises a material selected from the group consisting of tungsten (W), molybdenum (Mo), titanium (Ti), titanium tungsten (TiW), titanium nitride (TiN), tantalum (Ta), tantalum nitride (TaN), nickel chromium (NiCr), and nickel chromium silicon (NiCrSi).

9. A method for die-to-wafer bonding, said method comprising:

providing an integrated circuit (IC) die including at least one active device, said IC die having an IC substrate side and a metallization side;

providing a phase-change material (PCM) switch wafer, said PCM switch wafer having a heat spreading side and a radio frequency (RF) terminal side;

bonding said metallization side of said IC die to said heat spreading side of said PCM switch wafer;

forming a heating element between a heat spreader and a PCM in said PCM switch wafer.

10. The method of claim 9, further comprising removing a substrate of said PCM switch wafer from said RF terminal side of said PCM switch wafer.

11. The method of claim 10, wherein said removing said substrate of said PCM switch wafer from said RF terminal side of said PCM switch wafer comprises etching to an etch stop layer or a buried oxide layer.

12. The method of claim 9, wherein said heat spreader is a semiconductor heat spreader comprising epitaxial silicon or bulk silicon.

13. A method for die-to-wafer bonding, said method comprising:

providing an integrated circuit (IC) wafer including at least one active device, said IC wafer having an IC substrate side and a metallization side;

providing a phase-change material (PCM) switch die, said PCM switch die including a heating element between a heat spreader and a PCM in said PCM switch die, said PCM switch die having a heat spreading side and a radio frequency (RF) terminal side;

bonding said RF terminal side of said PCM switch die to said metallization side of said IC wafer.

14. The method of claim 13, wherein said heat spreader is a semiconductor heat spreader comprising epitaxial silicon or bulk silicon.

17. A method for wafer-to-wafer bonding, said method comprising:

providing an integrated circuit (IC) wafer having an IC substrate side and a metallization side;

providing a phase-change material (PCM) switch wafer having a heat spreading side and a radio frequency (RF) terminal side;

bonding said heat spreading side of said PCM switch wafer to said metallization side of said IC wafer.

18. The method of claim 17, further comprising removing a substrate of said PCM switch wafer from said RF terminal side of said PCM switch wafer.

19. The method of claim 18, wherein said removing said substrate of said PCM switch wafer from said RF terminal side of said PCM switch wafer comprises etching to an etch stop layer or a buried oxide layer.

20. The method of claim 17, wherein said heat spreader is a semiconductor heat spreader comprising epitaxial silicon or bulk silicon.

21. The method of claim 17, wherein said PCM comprises a material selected from the group consisting of germanium telluride (Ge_XTe_Y), germanium antimony telluride (Ge_XSb_YTe_Z), germanium selenide (Ge_XSe_Y), and any other chalcogenide.

22. A method for die-to-wafer bonding, said method comprising:

providing an integrated circuit (IC) wafer having an IC substrate side and a metallization side;

providing a phase-change material (PCM) switch die having a heat spreader and a PCM;

said PCM switch die having a heat spreading side and a radio frequency (RF) terminal side;

bonding said RF terminal side of said PCM switch die to said metallization side of said IC wafer.

23. The method of claim 22, wherein said heat spreader is a semiconductor heat spreader comprising epitaxial silicon or bulk silicon.

24. The method of claim 22, wherein said PCM comprises a material selected from the group consisting of germanium telluride (Ge_XTe_Y), germanium antimony telluride (Ge_XSb_YTe_Z), germanium selenide (Ge_XSe_Y), and any other chalcogenide.