Area-selective deposition of metal nitride to fabricate devices

Patent metadata

Field	Value
Publication number	US-2022190229-A1
Application number	US-202017118192-A
Country	US
Kind code	A1
Filing date	Dec 10, 2020
Priority date	Dec 10, 2020
Publication date	Jun 16, 2022
Grant date	—

Abstract

Embodiments are provided for fabrication of superconducting devices using area-selective deposition of a metal nitride. In some embodiments, a method can include providing a thermally treated carbon layer, and selectively depositing a metal nitride using the thermally treated carbon layer for formation of a superconducting device.

First claim

What is claimed is:

1 . A method, comprising:
providing a thermally treated carbon layer; selectively depositing a metal nitride using the thermally treated carbon layer for formation of a superconducting device.

2 . The method of claim 1 , wherein the providing comprises annealing a layer of amorphous carbon at a temperature within a range from about 500° C. to about 1000° C., resulting in formation of sp 2 -hybridized carbon in the thermally treated carbon layer.

3 . The method of claim 1 , wherein the selectively depositing comprises causing a thermal reaction between titanium chloride and ammonia at a temperature within a range from about 250° C. to about 400° C.

4 . The method of claim 1 , wherein the selectively depositing comprises using a plasma enhanced atomic layer deposition process using hydrogen plasma and a niobium precursor containing nitrogen.

5 . The method of claim 1 , wherein the selectively depositing comprises,
forming a first electrode; and forming a second electrode adjacent to the first electrode, the method further comprising forming a Josephson junction by depositing an insulator layer forming a first interface with the first electrode and a second interface with the second electrode, the insulator layer comprising a second metal nitride.

6 . The method of claim 1 , wherein the thermally treated carbon layer defines a growth region devoid of carbon and exposing a surface of a substrate, the method further comprising depositing a titanium nitride layer on the growth region.

7 . The method of claim 6 , wherein the substrate comprises at least one of a SiO 2 substrate or a SiN substrate.

8 . The method of claim 1 , wherein the providing comprises depositing amorphous carbon onto a substrate using an electron-beam evaporation process with a target of graphite.

9 . The method of claim 8 , wherein the depositing comprises depositing the amorphous carbon onto one of a Si substrate, a sapphire substrate, or a metal thin film.

10 . The method of claim 8 , further comprising treating the substrate with an acid before depositing the amorphous carbon.

11 . The method of claim 10 , wherein the treating comprises treating a silicon substrate with hydrofluoric acid.

12 . The method of claim 1 , wherein the providing comprises depositing a layer of carbon onto a substrate, the layer of carbon having a uniform thickness within a range from about 30 nm to about 100 nm.

13 . The method of claim 12 , wherein the depositing comprises maintaining a base pressure of about 10 −7 Torr within a deposition chamber containing the substrate and using a focused electron beam directed to a carbon target.

14 . A method, comprising:
annealing a pattern of carbonaceous sections present in a layer of carbon at a temperature within a range from about 500° C. to about 1000° C.; and selectively depositing a metal nitride using the annealed pattern to form a superconducting device.

15 . The method of claim 14 , wherein the selectively depositing comprises depositing the metal nitride on the pattern via an atomic layer deposition (ALD) process, the metal nitride comprising one of TiN, NbN, TaN, or ZrN.

16 . The method of claim 14 , further comprising forming the layer of carbon by treating a substrate prior to the annealing, wherein the treating comprises:
applying a photoresist coating to the substrate; forming the pattern by exposing and developing the photoresist coating; using an acid to remove exposed portions of a native oxide present on a surface of the substrate, resulting in exposed portions of the surface; and depositing amorphous carbon onto the exposed portions of the surface using physical vapor deposition (PVD) to form the layer of carbon.

17 . The method of claim 16 , further comprising removing the photoresist coating via at least one of a liquid solution of tetramethylammonium hydroxide (TMAH) or use of a Ge lift-off layer.

18 . The method of claim 16 , wherein removing the exposed portions of the native oxide comprises applying a wet etchant including hydrofluoric acid.

19 . A method, comprising:
forming a first electrode by selectively depositing a metal nitride using a thermally treated carbon layer; forming an insulator layer using the thermally treated carbon layer, the insulator layer forming a first interface with the first electrode; and forming a second electrode by selectively depositing the metal nitride using the thermally treated carbon layer, the second electrode forming a second interface with the insulator layer.

20 . The method of claim 19 , wherein forming the insulator layer comprises causing a thermal reaction between trimethylaluminum and ammonia.

Assignees

• IBM

Inventors

• Wojtecki Rudy J
• Farmer Damon Brooks
• Rettner Charles Thomas
• Arellano Noel
• Friz Alexander
• Copel Matthew W

Classifications

• C23C14/0605

  Carbon · CPC title

• C23C16/04

  Coating on selected surface areas, e.g. using masks · CPC title

• C23C14/30

  by electron bombardment · CPC title

• C23C16/45536

  Use of plasma, radiation or electromagnetic fields · CPC title

• H01L39/2416 Primary

  Electricity · mapped topic