IP Library › Granted Patent US 9,748,334
Granted Patent B1
US 9,748,334 · App. 15/046,723 · Granted Aug 29, 2017

Fabrication of nanomaterial T-gate transistors with charge transfer doping layer

Inventors: Sarunya Bangsaruntip (Mount Kisco, NY); Michael Engel (Ossining, NY); Shu-Jen Han (Cortlandt Manor, NY)
Assignee: International Business Machines Corporation
H01L29/0669H01L21/02603H01L21/02606H01L29/42376H01L29/66477H01L29/78H01L51/0048H01L51/057
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Quick Facts
Patent No.
US 9,748,334
App. No.
15/046,723
Granted
Aug 29, 2017
Kind
B1
Abstract

A field effect transistor including a dielectric layer on a substrate, a nano-structure material (NSM) layer on the dielectric layer, a source electrode and a drain electrode formed on the NSM layer, a gate dielectric formed on at least a portion of the NSM layer between the source electrode and the drain electrode, a T-shaped gate electrode formed between the source electrode and the drain electrode, where the NSM layer forms a channel of the FET, and a doping layer on the NSM layer extending at least from the sidewall of the source electrode to a first sidewall of the gate dielectric, and from a sidewall of the drain electrode to a second sidewall of the gate dielectric.

Claims (22)

1. A method of fabricating a nanostructure material field effect transistor (NSM FET) comprising:

forming a NSM layer on at least a portion of a dielectric layer;

forming a source electrode and a drain electrode on at least a portion of the NSM layer;

forming a gate dielectric on at least a portion of the NSM layer between the source electrode and the drain electrode;

forming a T-shaped gate electrode between the source electrode and the drain electrode on the gate dielectric, wherein the NSM layer forms a channel of the FET, and the T-shaped gate electrode is formed by forming sacrificial spacer material on exposed portions of the NSM layer; and

forming a doping layer directly on the surface of the NSM layer, where the doping layer extends at least from a sidewall of the source electrode to a first sidewall of the gate dielectric, and at least from a sidewall of the drain electrode to a second sidewall of the gate dielectric, wherein the gate dielectric is deposited over the sacrificial spacer material and the NSM layer, the T-shaped gate electrode material is deposited on the gate dielectric, the T-shaped gate electrode material and the gate dielectric are patterned and removed to form a gate electrode having a bottom surface with a width in the range of about 5 nm to about 500 nm, and a top surface with a width and surface area greater than the bottom surface of the T-shaped gate electrode, and the sacrificial spacer material is removed.

2. The method of fabricating the NSM FET of claim 1 , wherein the NSM layer includes carbon (C), boro-carbon nitrides (e.g., BC 2 N), transition metal dichalcogenides, group IV semiconductors, II-VI semiconductors, or III-V semiconductors.

3. The method of fabricating the NSM FET of claim 1 , wherein the NSM layer includes single-walled nanotubes (SWNTs), double-walled nanotubes (DWNTs), multi-walled nanotubes (MWNTs), chemically modified nanotubes, 2-dimensional lattice, or semiconducting nanowires.

4. The field effect transistor of claim 3 , wherein the SWNTs, DWNTs, MWNTs, and chemically modified nanotubes are carbon SWNTs, carbon DWNTs, carbon MWNTs, chemically modified carbon nanotubes, and the 2-dimensional lattice is graphene.

5. The method of fabricating the NSM FET of claim 1 , wherein the NSM layer is formed by a wet method, where nano-structure material is deposited from a solution.

6. The method of fabricating the NSM FET of claim 1 , further comprising functionalizing the surface of the dielectric layer to increase adhesion of the NSM layer, and/or forming a wetting layer on at least a portion of the NSM layer to increase adhesion of the source and drain electrodes.

7. The method of fabricating the NSM FET of claim 6 , wherein the doping layer includes benzyl viologen, silicon nitride, silicon oxynitride, magnesium oxide, aluminum oxide, hafnium oxide, hafnium silicate, hafnium silicon oxynitride, triethyloxonium hexachloroantimonate ((CH 3 CH 2 )O + SbCl 6 − ), or combinations thereof.

8. The method of fabricating the NSM FET of claim 1 , wherein the doping layer is isotropically applied by ALD, CVD, or a wet deposition.

9. The method of fabricating the NSM FET of claim 1 , wherein a first extension region is formed between the T-shaped gate electrode and the source electrode, and a second extension region is formed between the T-shaped gate electrode and the drain electrode, wherein the doping layer covers the entire extension region between the source electrode and the T-shaped gate electrode, and the entire extension portion between the drain electrode and the T-shaped gate electrode.

10. A method of fabricating a nanostructure material field effect transistor (NSM FET) comprising:

forming a dielectric layer on at least a portion of a substrate;

forming a NSM layer on at least a portion of dielectric layer, wherein the NSM layer includes single-walled carbon nanotubes (SWNTs), double-walled carbon nanotubes (DWNTs), multi-walled carbon nanotubes (MWNTs), chemically modified carbon nanotubes, or graphene;

patterning the NSM layer to leave gaps between adjacent sections of NSM material to form a plurality of isolated active areas;

forming a source electrode and a drain electrode on at least a portion of the NSM layer forming an isolated active area;

forming a gate dielectric on the portion of the NSM layer between the source electrode and the drain electrode;

forming a T-shaped gate electrode between the source electrode and the drain electrode on the gate dielectric, wherein the NSM layer forms a channel of the FET, and the T-shaped gate electrode is formed by forming sacrificial spacer material on exposed portions of the NSM layer; and

forming a doping layer directly on the surface of the NSM layer, where the doping layer extends at least from a sidewall of the source electrode to a first sidewall of the gate dielectric, and at least from a sidewall of the drain electrode to a second sidewall of the gate dielectric, wherein the gate dielectric is deposited over the sacrificial spacer material and the NSM layer, the T-shaped gate electrode material is deposited on the gate dielectric, the T-shaped gate electrode material and the gate dielectric are patterned and removed to form a gate electrode having a bottom surface with a width in the range of about 5 nm to about 500 nm, and a top surface with a width and surface area greater than the bottom surface of the T-shaped gate electrode, and the sacrificial spacer material is removed.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 18, 2016
From: BANGSARUNTIP, SARUNYA; ENGEL, MICHAEL; HAN, SHU-JEN
To: INTERNATIONAL BUSINESS MACHINES CORPORATION
Reel/Frame 037764/0254 →