Nanotwinned nickel films with high strength and ductility

Patent metadata

Field	Value
Publication number	US-12305273-B2
Application number	US-202318350138-A
Country	US
Kind code	B2
Filing date	Jul 11, 2023
Priority date	Jul 15, 2022
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

Synthesis of high SFE nanotwinned metallic films with varying distributions of twin widths on a low SFE metallic layer using magnetron sputtering is disclosed. In various embodiments, a method for forming a nanotwinned metal film may include providing a single crystal silicon wafer, etching the single crystal silicon wafer, depositing a silver film onto the single crystal silicon wafer forming a silver buffer layer, and depositing a metallic film onto the silver buffer layer using sputtering at a controlled temperature.

First claim

What is claimed is:

1. A method of forming a nanotwinned metal film, comprising:
providing a single crystal silicon wafer;
etching the single crystal silicon wafer;
depositing a silver film onto the single crystal silicon wafer forming a silver buffer layer; and
depositing a metallic film onto the silver buffer layer using sputter deposition, wherein the metallic film comprises nickel, and wherein a first 100 nanometers of the metallic film is deposited at 300 degrees Celsius and a remainder of the metallic film is deposited at 80 degrees Celsius.

2. The method of claim 1 , wherein the sputter deposition is magnetron sputtering, and wherein the single crystal silicon wafer is etched using hydrofluoric acid.

3. The method of claim 1 , wherein the silver buffer layer has a thickness of about 25 nanometers.

4. The method of claim 1 , wherein the metallic film has a thickness of about 500 nanometers.

5. The method of claim 1 , wherein the metallic film has a thickness of about 2.2 micrometers.

6. The method of claim 1 , wherein the single crystal silicon wafer has a thickness of about 200 micrometers.

7. The method of claim 1 , wherein the single crystal silicon wafer has a Miller index of (111).

8. The method of claim 1 , further comprising rotating the single crystal silicon wafer during the depositing of the metallic film.

9. A method of synthesizing a nanotwinned nickel film, the method comprising:
providing a hydrofluoric acid-etched single crystal silicon wafer;
forming a silver buffer layer on the hydrofluoric acid-etched single crystal silicon wafer by depositing silver at 100 W and 3 mTorr Ar pressure while the hydrofluoric acid-etched single crystal silicon wafer is rotated at about 40 rpm;
using sputter deposition to deposit a nickel layer on the hydrofluoric acid-etched single crystal silicon wafer at a temperature and at a rate of about 5 nanometers per minute to form the nanotwinned nickel film;
adjusting the temperature while depositing the nickel layer to vary the distribution of twin widths in the nanotwinned nickel film; and
performing uniaxial tensile tests to obtain a stress-strain response of the nanotwinned nickel film.

Assignees

• Rajagopalan Jagannathan
• Berlia Rohit
• Univ Arizona State

Inventors

• Rajagopalan Jagannathan
• Berlia Rohit

Classifications

• C23C14/021 Primary

  Cleaning or etching treatments · CPC title

• C23C14/542

  Controlling the film thickness or evaporation rate · CPC title

• C23C14/025

  Metallic sublayers · CPC title

• C23C14/35

  by application of a magnetic field, e.g. magnetron sputtering {(C23C14/3457 takes precedence)} · CPC title

• C23C14/18 Primary

  on other inorganic substrates · CPC title