Preferably oriented nanotwinned Au film, method of preparing the same, and bonding structure comprising the same

Patent metadata

Field	Value
Publication number	US-10161054-B2
Application number	US-201715657269-A
Country	US
Kind code	B2
Filing date	Jul 24, 2017
Priority date	Aug 14, 2014
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

The present invention is related to a preferably oriented nanotwinned Au film, a method of preparing the same, and a bonding structure comprising the same. The nanotwinned Au film has a thickness direction. The nanotwinned Au film is stacked along a [220] crystallographic axis orientation in the thickness direction. At least 50% by volume of the nanotwinned Au film is composed of a plurality of nanotwinned Au grains which are adjacent to each other, arranged in a direction perpendicular to the thickness direction, and stacked along a [111] crystallographic axis orientation.

First claim

What is claimed is:

1. A method for preparing an oriented nanotwinned Au film, comprising:
(A) providing a plating apparatus comprising an anode, a cathode, a direct current supply, and a plating solution, wherein the direct current supply is electrically connected to the anode and the cathode that are immersed in the plating solution; and
(B) providing a direct current supply to provide a direct current for plating where an oriented nanotwinned Au film forms on a surface of the cathode;
wherein the oriented nanotwinned Au film is stacked along a [ 220 ] crystallographic axis orientation in a thickness direction of the oriented nanotwinned Au film; and at least 50% by volume of the oriented nanotwinned Au film is composed of a plurality of nanotwinned Au grains which are adjacent to each other, arranged in a direction perpendicular to the thickness direction, and stacked along a [ 111 ] crystallographic axis orientation; and the plating solution comprises a gold ion, a chloride ion, and an acid.

2. The method of claim 1 , wherein in step (B), the cathode or the plating solution is rotated at a rotational speed of 300-1500 rpm during plating.

3. The method of claim 1 , wherein in step (B), the direct current supply provides a direct current with a current density of 1-100 mA/cm 2 .

4. The method of claim 1 , wherein the plating solution further comprises at least one from the group consisting of: a surfactant, a lattice modification agent, and mixtures thereof.

5. The method of claim 1 , wherein the acid of the plating solution is at least one from the group consisting of: hydrochloric acid, nitric acid, and sulfuric acid.

6. The method of claim 1 , wherein the acid of the plating solution has a concentration of 5-15 g/L.

7. The method of claim 1 , wherein the gold ion of the plating solution is obtained by dissociation of a gold-containing salt which is at least one from the group consisting of: a gold sulfate and a gold sulfite.

8. The method of claim 1 , wherein the chloride ion of the plating solution is at least one from the group consisting of: hydrochloric acid, perchloric acid, chloric acid, chlorous acid, and hypochlorous acid.

Assignees

• Univ National Chiao Tung

Inventors

• Chen Chih
• Chiu Wei-Lan
• Chou Yi-Chia

Classifications

• C25D3/48 Primary

  of gold · CPC title

• B32B15/01

  all layers being exclusively metallic {(making layered metal workpieces by pressure cladding B23K20/22; making coatings with a metallic material characterised by its composition C23C30/00)} · CPC title

• C25D5/50

  by heat-treatment · CPC title

• B32B15/018

  one layer being formed of a noble metal or a noble metal alloy · CPC title

• C25D21/10

  Agitating of electrolytes; Moving of racks · CPC title