# US 10,770,438 B2 · Bonded two-die device including an integrated circuit (IC) die and a phase-change material (PCM) switch die

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- Number: US 10,770,438 B2
- Document ID: US10770438B2
- Status: Granted
- Kind: B2
- Application number: 16/672,240
- Filed: 2019-11-01
- Published: 2020-02-27
- Granted: 2020-09-08
- Earliest claimed: 2018-08-14
- Assignees: Newport Fab, LLC
- Applicants: Newport Fab, LLC
- Inventors: Gregory P. Slovin; David J. Howard
- Web page: https://patentgrep.com/patent/US10770438B2

## CPC

- H10W 90/00: Package configurations
- H10B 63/10: Phase change RAM [PCRAM, PRAM] devices
- H10N 70/011: {Manufacture or treatment of multistable switching devices}
- H10N 70/231: {based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect}
- H10N 70/823: {adapted for essentially horizontal current flow, e.g. bridge type devices}
- H10N 70/8413: {adapted for resistive heating}
- H10N 70/8613: {Heating or cooling means other than resistive heating electrodes, e.g. heater in parallel}
- H10N 70/8825: {Selenides, e.g. GeSe}
- H10N 70/8828: {Tellurides, e.g. GeSbTe}
- 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)
- H10W 44/20: at high-frequency [HF] or radio frequency [RF]
- H10D 88/00: Three-dimensional [3D] integrated devices
- H10W 72/0198: {batch processes}
- H10W 72/07331: {Connecting techniques}
- H10W 80/327: {characterised by the direct bonding of insulating parts, e.g. of silicon oxide layers}
- H10W 90/732: {between stacked chips}
- H10W 90/792: {between multiple chips}
- H10W 99/00: Subject matter not provided for in other groups of this subclass
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- H10B: ELECTRONIC MEMORY DEVICES
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## 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

### Claim 1

A bonded two-die device comprising:
an integrated circuit (IC) die including at least one active device, said IC die having an IC substrate side and a metallization side;
a phase-change material (PCM) switch die, said PCM switch die having a heat spreading side and a radio frequency (RF) terminal side, said PCM switch die including a heating element between a heat spreader and a PCM;
said heat spreading side of said PCM switch die being bonded to said metallization side of said IC die.

### Claim 2 (depends on 1)

The bonded two-die device of claim 1, further comprising a bonding oxide between said heat spreading side of said PCM switch die and said metallization side of said IC die.

### Claim 3 (depends on 1)

The bonded two-die device of claim 1, wherein said heat spreader is a semiconductor heat spreader comprising epitaxial silicon or bulk silicon.

### Claim 4 (depends on 1)

The bonded two-die device of claim 1, wherein said at least one active device in said IC die comprises a CMOS device, a BiCMOS device, a SiGe device, or a group III-V device.

### Claim 5 (depends on 1)

The bonded two-die device of claim 1, wherein said PCM in said PCM switch die comprises passive segments and an active segment, wherein RF terminals of said PCM switch die are connect to said passive segments, and wherein said heating element is transverse to said PCM and is aligned with said active segment.

### Claim 6

A bonded two-die device comprising:
an integrated circuit (IC) die including at least one active device, said IC die having an IC substrate side and a metallization side;
a phase-change material (PCM) switch die, said PCM switch die having a heat spreading side and a radio frequency (RF) terminal side, said PCM switch die including a heating element between a heat spreader and a PCM;
said RF terminal side of said PCM switch die being bonded to said metallization side of said IC die.

### Claim 7 (depends on 6)

The bonded two-die device of claim 6, further comprising a bonding oxide between said RF terminal side of said PCM switch die and said metallization side of said IC die.

### Claim 8 (depends on 6)

The bonded two-die device of claim 6, wherein said heat spreader is a semiconductor heat spreader comprising epitaxial silicon or bulk silicon.

### Claim 9 (depends on 6)

The bonded two-die device of claim 6, wherein said at least one active device in said IC die comprises a CMOS device, a BiCMOS device, a SiGe device, or a group III-V device.

### Claim 10 (depends on 6)

The bonded two-die device of claim 6, wherein said PCM in said PCM switch die comprises passive segments and an active segment, wherein RF terminals of said PCM switch die are connected to said passive segments, and wherein said heating element is transverse to said PCM and is aligned with said active segment.

### Claim 11 (depends on 1)

The bonded two-die device of claim 1, wherein said PCM comprises a material selected from the group consisting of germanium telluride (GeXTeY), germanium antimony telluride (GeXSbYTeZ), germanium selenide (GeXSeY), and any other chalcogenide.

### Claim 12 (depends on 1)

The bonded two-die device 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).

### Claim 13 (depends on 6)

The bonded two-die device of claim 6, wherein said PCM comprises a material selected from the group consisting of germanium telluride (GeXTeY), germanium antimony telluride (GeXSbYTeZ), germanium selenide (GeXSeY), and any other chalcogenide.

### Claim 14 (depends on 6)

The bonded two-die device of claim 6, 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).

### Claim 15

A bonded two-die device comprising:
an integrated circuit (IC) die including at least one active device, said IC die having an IC substrate side and a metallization side;
a phase-change material (PCM) switch die, said PCM switch die having a heat spreading side and a radio frequency (RF) terminal side;
said heat spreading side of said PCM switch die being bonded to said metallization side of said IC die.

### Claim 16 (depends on 15)

The bonded two-die device of claim 15, further comprising a bonding oxide between said heat spreading side of said PCM switch die and said metallization side of said IC die.

### Claim 17 (depends on 15)

The bonded two-die device of claim 15, wherein said heat spreader is a semiconductor heat spreader comprising epitaxial silicon or bulk silicon.

### Claim 18 (depends on 15)

The bonded two-die device of claim 15, wherein said at least one active device in said IC die comprises a CMOS device, a BiCMOS device, a SiGe device, or a group r-V device.

### Claim 19 (depends on 15)

The bonded two-die device of claim 15, wherein said PCM comprises a material selected from the group consisting of germanium telluride (GeXTeY), germanium antimony telluride (GeXSbYTeZ), germanium selenide (GeXSeY), and any other chalcogenide.