Process for forming homoepitaxial tunnel barriers with hydrogenated graphene-on-graphene for room temperature electronic device applications

Patent metadata

Field	Value
Publication number	US-10128357-B2
Application number	US-201715426119-A
Country	US
Kind code	B2
Filing date	Feb 7, 2017
Priority date	Feb 18, 2016
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

A homoepitaxial, ultrathin tunnel barrier-based electronic device in which the tunnel barrier and transport channel are made of the same material—graphene.

First claim

What we claim is:

1. A method of making a homoepitaxial tunnel barrier with hydrogenated graphene-on-graphene, comprising:
growing graphene by chemical vapor deposition via decomposition of methane in a copper foil enclosure;
removing the copper foil by etching;
transferring and stacking graphene layers on a substrate;
defining graphene mesas utilizing deep-UV lithography and an etch mask with PMMA and oxygen plasma;
rinsing in acetone and isopropyl alcohol and removing the etch mask;
defining reference contacts and bond pads;
depositing Ti/Au using electron beam deposition;
encapsulating edges of the graphene layers utilizing deep-UV lithography and a MMA/PMMA mask;
sputter-depositing SiN wherein the SiN is about 10 nm;
hydrogenating the graphene; and
forming the homoepitaxial tunnel barrier.

2. The method of making a homoepitaxial tunnel barrier with hydrogenated graphene-on-graphene of claim 1 wherein the step of transferring and stacking graphene layers on a substrate includes stacking 4 graphene layers and wherein after the step of hydrogenating a conductive channel is present in the layers.

3. The method of making a homoepitaxial tunnel barrier with hydrogenated graphene-on-graphene of claim 2 further including the step of:
depositing FM contacts via E-beam lithography.

4. A method of making a homoepitaxial tunnel barrier with hydrogenated graphene-on-graphene, comprising:
providing a multilayer stack of graphene having top layers and bottom layers;
encapsulating edges of the graphene layers utilizing deep-UV lithography and a MMA/PMMA mask;
sputter-depositing SiN wherein the SiN is about 10 nm;
hydrogenating the top layers of graphene; and
creating a homoepitaxial tunnel barrier.

5. A method of making a homoepitaxial tunnel barrier transport device with hydrogenated graphene-on-graphene, comprising:
growing a first monolayer graphene film;
transferring the first monolayer graphene film onto a SiO2/Si substrate;
growing a second monolayer graphene film;
transferring the second monolayer graphene film onto the top of the first monolayer graphene film;
hydrogenating the second monolayer graphene film;
forming the homoepitaxial tunnel barrier transport device with hydrogenated graphene-on-graphene; and
performing a second hydrogenation to hydrogenate the homoepitaxial tunnel barrier transport device with hydrogenated graphene-on-graphene.

6. The method of making a homoepitaxial tunnel barrier transport device with hydrogenated graphene-on-graphene of claim 5 , further comprising the step of utilizing the tunneling behavior.

7. The method of making a homoepitaxial tunnel barrier transport device with hydrogenated graphene-on-graphene of claim 5 , further comprising the step of operating the homoepitaxial tunnel barrier transport device with hydrogenated graphene-on-graphene as a spin valve.

8. The method of making a homoepitaxial tunnel barrier transport device with hydrogenated graphene-on-graphene of claim 5 further comprising the step of preventing any edge state conduction.

Assignees

• Us Navy

Inventors

• Friedman Adam L
• Van'T Erve Olaf M J
• Robinson Jeremy T
• Jonker Berend T
• Whitener Keith E

Classifications

• H10P95/92

  Formation of n- or p-type semiconductors, e.g. doping of graphene · CPC title

• H10P50/00

  Etching of wafers, substrates or parts of devices · CPC title

• H10P14/3452

  Microstructure · CPC title

• H10P14/3406

  Carbon, e.g. diamond-like carbon · CPC title

• H10P14/24

  using chemical vapour deposition [CVD] · CPC title