Stacked graphene field-effect transistor

Patent metadata

Field	Value
Publication number	US-9508801-B2
Application number	US-201514591988-A
Country	US
Kind code	B2
Filing date	Jan 8, 2015
Priority date	Jan 8, 2015
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

In an aspect of the present invention, a graphene field-effect transistor (GFET) structure is formed. The GFET structure comprises a wider portion and a narrow extension portion extending from the wider portion that includes one or more graphene layers edge contacted to source and drain contacts, wherein the source and drain contacts are self-aligned to the one or more graphene layers.

First claim

What is claimed is:

1. A graphene field-effect transistor (GFET) structure comprising:
a semiconductor substrate that has a dielectric coating;
a layer of metal overlaying the semiconductor substrate;
a first layer of gate dielectric overlaying the layer of metal;
a patterned layer of graphene overlaying a portion of the first layer of gate dielectric;
a second layer of gate dielectric overlaying the patterned layer of graphene;
a top layer of metal overlaying a topmost layer of gate dielectric;
a layer of dielectric overlaying the top layer of metal;
a source contact and a drain contact self-aligned to the graphene layer, wherein the graphene layer is edge-contacted to the source and drain contacts; and
wherein outer surfaces of the metal layers are oxidized.

2. The GFET structure of claim 1 ,
wherein the layer of metal and the top layer of metal comprise Aluminum; and
wherein the source contact and the drain contact comprise Chromium.

3. The GFET structure of claim 1 , further comprising:
a second layer of metal overlaying the second layer of gate dielectric;
a third layer of gate dielectric overlaying the second layer of metal;
a second patterned layer of graphene overlaying a portion of the third layer of gate dielectric; and
a fourth layer of gate dielectric overlaying the second patterned layer of graphene.

4. A graphene field-effect transistor (GFET) structure comprising:
a GFET structure on a semiconductor substrate, wherein:
the GFET structure includes a wider portion, wherein the wider portion comprises:
a layer of metal overlaying the semiconductor substrate;
a layer of gate dielectric overlaying the layer of metal;
a top layer of metal overlaying a topmost layer of gate dielectric;
a layer of dielectric overlaying the top layer of metal,
wherein outer surfaces of the metal layers are oxidized; and

the GFET structure includes a narrow extension portion extending from the wider portion that includes one or more graphene layers edge contacted to source and drain contacts, wherein the source and drain contacts are self-aligned to the one or more graphene layers.

5. The GFET structure of claim 4 , wherein the narrow extension portion comprises:
a layer of metal overlaying the semiconductor substrate;
a first layer of gate dielectric overlaying the layer of metal;
a patterned layer of graphene overlaying a portion of the first layer of gate dielectric;
a second layer of gate dielectric overlaying the patterned layer of graphene;
a top layer of metal overlaying a topmost layer of gate dielectric;
a layer of dielectric overlaying the top layer of metal;
a source contact and a drain contact self-aligned to the graphene layer, wherein the graphene layer is edge-contacted to the source and drain contacts; and
wherein outer surfaces of the metal layers are oxidized.

6. The GFET structure of claim 4 , wherein the wider portion further comprises:
a through hole via in the wider portion; and
a gate metal plug filling the through hole via in the wider portion.

7. The GFET structure of claim 5 ,
wherein the layer of metal and the top layer of metal comprise Aluminum; and
wherein the source contact and the drain contact comprise Chromium.

Assignees

• IBM

Inventors

• Franklin Aaron D
• Miyazoe Hiroyuki
• Oida Satoshi
• Smith Joshua T

Classifications

• H10P50/00

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

• H10P14/6314

  of a metallic layer · CPC title

• H10P14/3406

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

• H10D64/01364

  the semiconductor being diamond, semiconducting diamond-like carbon or graphene · CPC title

• H10D64/0114

  to diamond, semiconducting diamond-like carbon or graphene · CPC title