Granted Patent B2

US 12,305,273 · App. 18/350,138 · Granted May 20, 2025

Inventors: Jagannathan Rajagopalan (Tempe, AZ); Rohit Berlia (Tempe, AZ)

Assignee: ARIZONA BOARD OF REGENTS ON BEHALF OF ARIZONA STATE UNIVERSITY

C23C14/18C23C14/021C23C14/025C23C14/35C23C14/542

Abstract

Claims (18)

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.

Assignments (2)

Continuity (2)

References Cited (44)