Method of preparing metal surfaces

Patent metadata

Field	Value
Publication number	US-2016333459-A1
Application number	US-201614999340-A
Country	US
Kind code	A1
Filing date	Apr 26, 2016
Priority date	Apr 30, 2015
Publication date	Nov 17, 2016
Grant date	—

Abstract

A method of preparing an ultra-flat metal surface involves providing a layer of a crystalline metallic material on an ultra-flat substrate surface that is relatively harder than the metallic material layer and then impinging the metallic material layer with incoming metal atoms that are deposited as an additive crystalline layer thereon, wherein at least a lattice constant of the additive crystalline layer is different enough from a lattice constant of the crystalline metallic material layer resulting in a reduction of roughness of the surface of the metallic material layer adjacent to the substrate surface. The metallic material layer having an ultra-flat surface then is separated by template stripping or other technique from the substrate surface for further use of the ultra-flat surface.
27

First claim

We Claim:

1 . A method of preparing an ultra-flat metal surface, comprising:
providing a layer of a metallic material on an ultra-flat substrate surface wherein the substrate is relatively harder than the metallic material layer; impinging the metallic material layer residing on the substrate surface with incoming metall/metalloid atoms including depositing the incoming metallic atoms as an additive layer having at least a reference or measured lattice constant different enough from a reference or measured lattice constant of the metallic material layer that results in reduced surface roughness of the surface of the metallic material layer adjacent to the substrate surface; and separating the metallic material layer from the substrate surface.

2 . The method of claim 1 wherein the lattice constant mismatch % between the metallic atoms of the additive layer and the metallic atoms of the metallic material layer is greater than about 0.1% to achieve an average RMS surface roughness of less than 0.45 nm.

3 . The method of claim 2 wherein said average surface roughness is the range of about 0.18 nm to about 0.3 nm RMS.

4 . The method of claim 1 wherein the deposited additive layer has a reference or measured lattice constant and atomic binding energy represented by its reference redox potential different enough from a reference or measured lattice constant or atomic binding energy represented by reference redox potential of the metallic material layer that results in reduced surface roughness of the surface of the metallic material layer adjacent to the substrate surface.

5 . The method of claim 2 wherein the metallic material is ductile enough to be strained against the substrate surface in the presence of the mismatch of lattice constants by impingement and solidification of the incoming atoms.

6 . The method of claim 1 wherein the substrate material comprises a Si wafer, mica, or gypsum or a single crystal.

7 . The method of claim 1 wherein the metallic material comprises a noble metal comprising at least one of Au, Ag, Pt, and Pd.

8 . The method of claim 1 wherein the metallic material comprises a metal comprising at least one of Cu, Re, Ru, Ti, and V.

9 . The method of claim 1 wherein the metallic material layer is provided by physical vapor deposition of the metallic material on the substrate surface.

10 . The method of claim 1 wherein the incoming metal atoms are sputtered from a target source.

11 . The method of claim 1 wherein the incoming metal atoms comprise a transition metal comprising at least one of Fe, Ni, V, Cr, Mn, Ta, Sc, Zr, Nb, Ru, Pd, Cu, Ti, Zn, Re, and W.

12 . The method of claim 1 wherein the incoming atoms comprises a metal, a metalloid, or an alloy that comprises at least one of Al, Ga, In, Sn, and Bi.

13 . The method of claim 1 wherein the metallic material layer has a thickness from 100 nm to 600 nm or more.

14 . An ultra-flat metallic material layer including a surface with a surface roughness between about 0.18 to about 0.45 nm average RMS roughness and including an opposite surface having an additive layer comprised of metal atoms deposited thereon.

15 . A method of preparing a metal surface with controlled surface roughness of less than average roughness RMS of 5 nm, comprising:
providing a layer of a metallic material on a substrate surface wherein the substrate is relatively harder than the metallic material layer; impinging the metallic material layer residing on the substrate surface with incoming metallic atoms including depositing the incoming metallic atoms as an additive layer having at least a reference or measured lattice constant different enough from a reference or measured lattice constant of the metallic material of the metallic material layer that results in a controlled change in surface roughness of the surface of the metallic material layer adjacent to the substrate surface; and separating the metallic material layer from the substrate surface.

16 . The method of claim 15 wherein the deposited additive layer has a reference or measured lattice constant and atomic binding energy represented by its reference redox potential different enough from a reference or measured lattice constant and atomic binding energy represented by a reference redox potential of the metallic material layer that results in controlled change in surface roughness of the surface of the metallic material layer adjacent to the substrate surface.

17 . The method of claim 15 wherein the substrate material comprises a Si wafer, mica, gypsum, or a single crystal.

18 . The method of claim 15 wherein the metallic material comprises a noble metal comprising at least one of Au, Ag, Pt, and Pd.

19 . The method of claim 15 wherein the metallic material layer is provided by physical vapor deposition of the metallic material on the substrate surface.

20 . The method of claim 15 wherein the incoming metal atoms are deposited (by sputtering, CVD, electrochemically or by any other method) from a target source.

21 . The method of claim 15 wherein the incoming metal atoms comprise a transition metal comprising at least one of Fe, Ni, V, Cr, Mn, Ta, Sc, Zr, Nb, Ru, Pd, Cu, Ti, Zn, Re, and W.

22 . The method of claim 15 wherein the incoming atoms comprises a metal, a metalloid, or an alloy that comprises at least one of Al, Ga, In, Sn, Pb, and Bi.

23 . The method of claim 15 wherein the incoming atoms comprises an alkali or alkali-earth metal or an alloy that comprises at least one of Li, Ca, and Mg.

24 . The method of claim 15 wherein the metallic material layer has a thickness from 100 nm to 600 nm or more.

25 . The method of claim 15 wherein surface roughness is controlled in the range between about 0.18 to about 3.5 nm average RMS roughness.

26 . A metallic material layer including a surface with a surface roughness between about 0.18 to about 3.5 nm average RMS roughness and including an opposite surface having an additive layer comprised of metal atoms deposited thereon.

Assignees

• Univ Iowa State Res Found Inc

Inventors

• Thuo Martin
• Chen Jiahao
• Tevis Ian D

Classifications

• C23C14/30

  by electron bombardment · CPC title

• C23C14/025

  Metallic sublayers · CPC title

• C23C14/18

  on other inorganic substrates · CPC title

• C23C14/34

  Sputtering · CPC title

• C23C14/165 Primary

  by cathodic sputtering · CPC title