Patent
US 9,627,485VAPOR-TRAPPING GROWTH OF SINGLE-CRYSTALLINE GRAPHENE FLOWERS
Chongwu Zhou
US
Copyright © 2026 Matter42. All rights reserved.
Patent details
Patent
US 9,627,485Patent drawings and their descriptions. Click a drawing to enlarge it.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method comprising: placing a vessel comprising a quartz tube having an open end into a chemical vapor deposition chamber, wherein metal foil is positioned in the vessel, and wherein the open end of the vessel is closer to a first opening of the chemical vapor deposition chamber than a closed end of the vessel is to the first opening; evacuating the chemical vapor deposition chamber; flowing hydrogen gas through the chamber from the first opening of the chamber to a second opening of the chamber to achieve a first pressure less than atmospheric pressure; heating the atmosphere in the chamber to anneal the metal foil; flowing methane and hydrogen through the chamber from the first opening of the chamber to the second opening of the chamber to achieve a second pressure less than atmospheric pressure; and depositing carbon on the metal foil to yield a single-crystalline graphene layer on the metal foil.
The method of claim 1, wherein the methane and hydrogen introduced into the chamber do not flow through the vessel.
The method of claim 1, wherein a local environment between the metal foil and an interior of the vessel is different from an environment inside the chamber, and wherein the metal foil is a copper foil.
The method of claim 1, wherein the graphene layer is in the shape of a four- lobed flower, a six-lobed flower, or a combination thereof.
The method of claim 1, wherein a dimension of the graphene layer on the metal foil is up to 100 m.
The method of claim 1, further comprising adjusting a total pressure, a methane to hydrogen flow rate ratio, or both to obtain a desired morphology.
The method of claim 1, wherein a ratio of a flow rate of the methane to a flow rate of the hydrogen is between 1: 10 to 1: 20.
The method of claim 1, wherein a total pressure of methane and hydrogen is less than 200 mTorr.
The method of claim 1, further comprising removing the graphene layer from the metal foil.
The method of claim 1, wherein the graphene produces one set of symmetric six-fold electron diffraction pattern oriented in the same direction.
A single-crystalline graphene layer formed by the method of claim 1. withdrawn
A field effect transistor comprising a graphene layer formed by the method of claim 1. withdrawn
A method of forming a field effect transistor, the method comprising: providing a silicon substrate; providing a thermal oxide on the silicon substrate; transferring the graphene layer formed by the method of claim 1 from the metal foil onto the thermal oxide layer to form a graphene channel; depositing a source electrode at one end of the graphene channel; and depositing a drain electrode at another end of the graphene channel.
A device comprising the graphene layer formed using the method of claim 1, wherein the graphene layer is transferred onto hexagonal boron nitride (h-BN), and an electron SVG 14214173.09-01-2016.ISKZOIFHRXEAPX0.CLM.3.22.1239.2292.1280.2334.svg 0.14 0.137 Chemistry Black and white mobility in the device is about 20,000 cm 2 V-1. withdrawn
Embodiments described in the patent, grouped by the materials and process steps they use.
4 materials1 process step
Cu foil placed inside a half-inch quartz tube (single open end) which is placed inside a 2-inch CVD quartz tube. Chamber evacuated, 7 sccm H₂ introduced at 40 mTorr, temperature ramped to 1000 °C in 40 minutes, Cu foils annealed at 1000 °C for 20 minutes. Then 1 sccm CH₄ and 12.5 sccm H₂ introduced, pressure held at 200 mTorr for 30 minutes during growth. Chamber cooled to room temperature while CH₄/H₂ flow continued at 200 mTorr. Single-crystalline graphene flowers (four-lobe and six-lobe) up to 100 μm formed on the inner Cu foil; continuous polycrystalline film with etching formed on outer Cu foil.
4 materials1 process step
Graphene grown on Cu foil without quartz tube 140, using 0.5 sccm CH₄ and 25 sccm H₂ at total pressure of 150 mTorr. Other parameters identical to vapor-trapping recipe. Flower shapes were less uniform compared to vapor-trapping approach.
3 materials1 process step
Graphene flowers transferred from Cu foil onto Si/SiO₂ substrate. Field effect transistors fabricated with source and drain electrodes; fitted device mobility ~4,200 cm2 V-1 s-1 obtained.
2 materials
Graphene layer transferred onto hexagonal boron nitride (h-BN) to form a Hall-bar device. Electron mobility ~20,000 cm2 V-1 s-1 obtained.
Layer stacks claimed or described, ordered top of device to substrate.
graphene field effect transistor on Si/SiO₂
graphene Hall-bar device on h-BN
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
fitted device mobility on Si/SiO2 | 4200 cm2 V-1 s-1 | C |
electron mobility on h-BN Hall-bar device | 20000 cm2 V-1 s-1 |
Related documents with shared materials, methods, properties, or citations.
Patent details
Patent
US 9,627,485Patent drawings and their descriptions. Click a drawing to enlarge it.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method comprising: placing a vessel comprising a quartz tube having an open end into a chemical vapor deposition chamber, wherein metal foil is positioned in the vessel, and wherein the open end of the vessel is closer to a first opening of the chemical vapor deposition chamber than a closed end of the vessel is to the first opening; evacuating the chemical vapor deposition chamber; flowing hydrogen gas through the chamber from the first opening of the chamber to a second opening of the chamber to achieve a first pressure less than atmospheric pressure; heating the atmosphere in the chamber to anneal the metal foil; flowing methane and hydrogen through the chamber from the first opening of the chamber to the second opening of the chamber to achieve a second pressure less than atmospheric pressure; and depositing carbon on the metal foil to yield a single-crystalline graphene layer on the metal foil.
The method of claim 1, wherein the methane and hydrogen introduced into the chamber do not flow through the vessel.
The method of claim 1, wherein a local environment between the metal foil and an interior of the vessel is different from an environment inside the chamber, and wherein the metal foil is a copper foil.
The method of claim 1, wherein the graphene layer is in the shape of a four- lobed flower, a six-lobed flower, or a combination thereof.
The method of claim 1, wherein a dimension of the graphene layer on the metal foil is up to 100 m.
The method of claim 1, further comprising adjusting a total pressure, a methane to hydrogen flow rate ratio, or both to obtain a desired morphology.
The method of claim 1, wherein a ratio of a flow rate of the methane to a flow rate of the hydrogen is between 1: 10 to 1: 20.
The method of claim 1, wherein a total pressure of methane and hydrogen is less than 200 mTorr.
The method of claim 1, further comprising removing the graphene layer from the metal foil.
The method of claim 1, wherein the graphene produces one set of symmetric six-fold electron diffraction pattern oriented in the same direction.
A single-crystalline graphene layer formed by the method of claim 1. withdrawn
A field effect transistor comprising a graphene layer formed by the method of claim 1. withdrawn
A method of forming a field effect transistor, the method comprising: providing a silicon substrate; providing a thermal oxide on the silicon substrate; transferring the graphene layer formed by the method of claim 1 from the metal foil onto the thermal oxide layer to form a graphene channel; depositing a source electrode at one end of the graphene channel; and depositing a drain electrode at another end of the graphene channel.
A device comprising the graphene layer formed using the method of claim 1, wherein the graphene layer is transferred onto hexagonal boron nitride (h-BN), and an electron SVG 14214173.09-01-2016.ISKZOIFHRXEAPX0.CLM.3.22.1239.2292.1280.2334.svg 0.14 0.137 Chemistry Black and white mobility in the device is about 20,000 cm 2 V-1. withdrawn
Embodiments described in the patent, grouped by the materials and process steps they use.
4 materials1 process step
Cu foil placed inside a half-inch quartz tube (single open end) which is placed inside a 2-inch CVD quartz tube. Chamber evacuated, 7 sccm H₂ introduced at 40 mTorr, temperature ramped to 1000 °C in 40 minutes, Cu foils annealed at 1000 °C for 20 minutes. Then 1 sccm CH₄ and 12.5 sccm H₂ introduced, pressure held at 200 mTorr for 30 minutes during growth. Chamber cooled to room temperature while CH₄/H₂ flow continued at 200 mTorr. Single-crystalline graphene flowers (four-lobe and six-lobe) up to 100 μm formed on the inner Cu foil; continuous polycrystalline film with etching formed on outer Cu foil.
4 materials1 process step
Graphene grown on Cu foil without quartz tube 140, using 0.5 sccm CH₄ and 25 sccm H₂ at total pressure of 150 mTorr. Other parameters identical to vapor-trapping recipe. Flower shapes were less uniform compared to vapor-trapping approach.
3 materials1 process step
Graphene flowers transferred from Cu foil onto Si/SiO₂ substrate. Field effect transistors fabricated with source and drain electrodes; fitted device mobility ~4,200 cm2 V-1 s-1 obtained.
2 materials
Graphene layer transferred onto hexagonal boron nitride (h-BN) to form a Hall-bar device. Electron mobility ~20,000 cm2 V-1 s-1 obtained.
Layer stacks claimed or described, ordered top of device to substrate.
graphene field effect transistor on Si/SiO₂
graphene Hall-bar device on h-BN
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
fitted device mobility on Si/SiO2 | 4200 cm2 V-1 s-1 | C |
electron mobility on h-BN Hall-bar device | 20000 cm2 V-1 s-1 |
Related documents with shared materials, methods, properties, or citations.
Patent details
Patent
US 9,627,485Patent drawings and their descriptions. Click a drawing to enlarge it.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method comprising: placing a vessel comprising a quartz tube having an open end into a chemical vapor deposition chamber, wherein metal foil is positioned in the vessel, and wherein the open end of the vessel is closer to a first opening of the chemical vapor deposition chamber than a closed end of the vessel is to the first opening; evacuating the chemical vapor deposition chamber; flowing hydrogen gas through the chamber from the first opening of the chamber to a second opening of the chamber to achieve a first pressure less than atmospheric pressure; heating the atmosphere in the chamber to anneal the metal foil; flowing methane and hydrogen through the chamber from the first opening of the chamber to the second opening of the chamber to achieve a second pressure less than atmospheric pressure; and depositing carbon on the metal foil to yield a single-crystalline graphene layer on the metal foil.
The method of claim 1, wherein the methane and hydrogen introduced into the chamber do not flow through the vessel.
The method of claim 1, wherein a local environment between the metal foil and an interior of the vessel is different from an environment inside the chamber, and wherein the metal foil is a copper foil.
The method of claim 1, wherein the graphene layer is in the shape of a four- lobed flower, a six-lobed flower, or a combination thereof.
The method of claim 1, wherein a dimension of the graphene layer on the metal foil is up to 100 m.
The method of claim 1, further comprising adjusting a total pressure, a methane to hydrogen flow rate ratio, or both to obtain a desired morphology.
The method of claim 1, wherein a ratio of a flow rate of the methane to a flow rate of the hydrogen is between 1: 10 to 1: 20.
The method of claim 1, wherein a total pressure of methane and hydrogen is less than 200 mTorr.
The method of claim 1, further comprising removing the graphene layer from the metal foil.
The method of claim 1, wherein the graphene produces one set of symmetric six-fold electron diffraction pattern oriented in the same direction.
A single-crystalline graphene layer formed by the method of claim 1. withdrawn
A field effect transistor comprising a graphene layer formed by the method of claim 1. withdrawn
A method of forming a field effect transistor, the method comprising: providing a silicon substrate; providing a thermal oxide on the silicon substrate; transferring the graphene layer formed by the method of claim 1 from the metal foil onto the thermal oxide layer to form a graphene channel; depositing a source electrode at one end of the graphene channel; and depositing a drain electrode at another end of the graphene channel.
A device comprising the graphene layer formed using the method of claim 1, wherein the graphene layer is transferred onto hexagonal boron nitride (h-BN), and an electron SVG 14214173.09-01-2016.ISKZOIFHRXEAPX0.CLM.3.22.1239.2292.1280.2334.svg 0.14 0.137 Chemistry Black and white mobility in the device is about 20,000 cm 2 V-1. withdrawn
Embodiments described in the patent, grouped by the materials and process steps they use.
4 materials1 process step
Cu foil placed inside a half-inch quartz tube (single open end) which is placed inside a 2-inch CVD quartz tube. Chamber evacuated, 7 sccm H₂ introduced at 40 mTorr, temperature ramped to 1000 °C in 40 minutes, Cu foils annealed at 1000 °C for 20 minutes. Then 1 sccm CH₄ and 12.5 sccm H₂ introduced, pressure held at 200 mTorr for 30 minutes during growth. Chamber cooled to room temperature while CH₄/H₂ flow continued at 200 mTorr. Single-crystalline graphene flowers (four-lobe and six-lobe) up to 100 μm formed on the inner Cu foil; continuous polycrystalline film with etching formed on outer Cu foil.
4 materials1 process step
Graphene grown on Cu foil without quartz tube 140, using 0.5 sccm CH₄ and 25 sccm H₂ at total pressure of 150 mTorr. Other parameters identical to vapor-trapping recipe. Flower shapes were less uniform compared to vapor-trapping approach.
3 materials1 process step
Graphene flowers transferred from Cu foil onto Si/SiO₂ substrate. Field effect transistors fabricated with source and drain electrodes; fitted device mobility ~4,200 cm2 V-1 s-1 obtained.
2 materials
Graphene layer transferred onto hexagonal boron nitride (h-BN) to form a Hall-bar device. Electron mobility ~20,000 cm2 V-1 s-1 obtained.
Layer stacks claimed or described, ordered top of device to substrate.
graphene field effect transistor on Si/SiO₂
graphene Hall-bar device on h-BN
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
fitted device mobility on Si/SiO2 | 4200 cm2 V-1 s-1 | C |
electron mobility on h-BN Hall-bar device | 20000 cm2 V-1 s-1 |
Related documents with shared materials, methods, properties, or citations.
Patent details
Patent
US 9,627,485Patent drawings and their descriptions. Click a drawing to enlarge it.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method comprising: placing a vessel comprising a quartz tube having an open end into a chemical vapor deposition chamber, wherein metal foil is positioned in the vessel, and wherein the open end of the vessel is closer to a first opening of the chemical vapor deposition chamber than a closed end of the vessel is to the first opening; evacuating the chemical vapor deposition chamber; flowing hydrogen gas through the chamber from the first opening of the chamber to a second opening of the chamber to achieve a first pressure less than atmospheric pressure; heating the atmosphere in the chamber to anneal the metal foil; flowing methane and hydrogen through the chamber from the first opening of the chamber to the second opening of the chamber to achieve a second pressure less than atmospheric pressure; and depositing carbon on the metal foil to yield a single-crystalline graphene layer on the metal foil.
The method of claim 1, wherein the methane and hydrogen introduced into the chamber do not flow through the vessel.
The method of claim 1, wherein a local environment between the metal foil and an interior of the vessel is different from an environment inside the chamber, and wherein the metal foil is a copper foil.
The method of claim 1, wherein the graphene layer is in the shape of a four- lobed flower, a six-lobed flower, or a combination thereof.
The method of claim 1, wherein a dimension of the graphene layer on the metal foil is up to 100 m.
The method of claim 1, further comprising adjusting a total pressure, a methane to hydrogen flow rate ratio, or both to obtain a desired morphology.
The method of claim 1, wherein a ratio of a flow rate of the methane to a flow rate of the hydrogen is between 1: 10 to 1: 20.
The method of claim 1, wherein a total pressure of methane and hydrogen is less than 200 mTorr.
The method of claim 1, further comprising removing the graphene layer from the metal foil.
The method of claim 1, wherein the graphene produces one set of symmetric six-fold electron diffraction pattern oriented in the same direction.
A single-crystalline graphene layer formed by the method of claim 1. withdrawn
A field effect transistor comprising a graphene layer formed by the method of claim 1. withdrawn
A method of forming a field effect transistor, the method comprising: providing a silicon substrate; providing a thermal oxide on the silicon substrate; transferring the graphene layer formed by the method of claim 1 from the metal foil onto the thermal oxide layer to form a graphene channel; depositing a source electrode at one end of the graphene channel; and depositing a drain electrode at another end of the graphene channel.
A device comprising the graphene layer formed using the method of claim 1, wherein the graphene layer is transferred onto hexagonal boron nitride (h-BN), and an electron SVG 14214173.09-01-2016.ISKZOIFHRXEAPX0.CLM.3.22.1239.2292.1280.2334.svg 0.14 0.137 Chemistry Black and white mobility in the device is about 20,000 cm 2 V-1. withdrawn
Embodiments described in the patent, grouped by the materials and process steps they use.
4 materials1 process step
Cu foil placed inside a half-inch quartz tube (single open end) which is placed inside a 2-inch CVD quartz tube. Chamber evacuated, 7 sccm H₂ introduced at 40 mTorr, temperature ramped to 1000 °C in 40 minutes, Cu foils annealed at 1000 °C for 20 minutes. Then 1 sccm CH₄ and 12.5 sccm H₂ introduced, pressure held at 200 mTorr for 30 minutes during growth. Chamber cooled to room temperature while CH₄/H₂ flow continued at 200 mTorr. Single-crystalline graphene flowers (four-lobe and six-lobe) up to 100 μm formed on the inner Cu foil; continuous polycrystalline film with etching formed on outer Cu foil.
4 materials1 process step
Graphene grown on Cu foil without quartz tube 140, using 0.5 sccm CH₄ and 25 sccm H₂ at total pressure of 150 mTorr. Other parameters identical to vapor-trapping recipe. Flower shapes were less uniform compared to vapor-trapping approach.
3 materials1 process step
Graphene flowers transferred from Cu foil onto Si/SiO₂ substrate. Field effect transistors fabricated with source and drain electrodes; fitted device mobility ~4,200 cm2 V-1 s-1 obtained.
2 materials
Graphene layer transferred onto hexagonal boron nitride (h-BN) to form a Hall-bar device. Electron mobility ~20,000 cm2 V-1 s-1 obtained.
Layer stacks claimed or described, ordered top of device to substrate.
graphene field effect transistor on Si/SiO₂
graphene Hall-bar device on h-BN
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
fitted device mobility on Si/SiO2 | 4200 cm2 V-1 s-1 | C |
electron mobility on h-BN Hall-bar device | 20000 cm2 V-1 s-1 |
Related documents with shared materials, methods, properties, or citations.
Pressure | ≤ 200 mTorr | — |
Pressure | ≤ 200 mTorr | — |
Pressure | ≤ 200 mTorr | — |
Pressure | ≤ 200 mTorr | — |