Electrical connecting structure having nano-twins copper
Disclosed herein is an electrical connecting structure having nano-twins copper, including a first substrate having a first nano-twins copper layer and a second substrate having a second nano-twins copper layer. The first nano-twins copper layer includes a plurality of first nano-twins copper grains. The second nano-twins copper layer includes a plurality of second nano-twins copper grains. The first nano-twins copper layer is joined with the second nano-twins copper layer. At least a portion of the first nano-twins copper grains extend into the second nano-twins copper layer, or at least a portion of the second nano-twins copper grains extend into the first nano-twins copper layer.
1. An electrical connecting structure having nano-twins copper, comprising:
a first substrate having a first nano-twins copper layer, wherein the first nano-twins copper layer comprises a plurality of first nano-twins copper grains; and
a second substrate having a second nano-twins copper layer, wherein the second nano-twins copper layer comprises a plurality of second nano-twins copper grains, the first nano-twins copper layer being joined with the second nano-twins copper layer;
wherein at least a portion of the first nano-twins copper grains extend into the second nano-twins copper layer, or at least a portion of the second nano-twins copper grains extend into the first nano-twins copper layer;
wherein a joining interface is between the first nano-twins copper layer and the second nano-twins copper layer, at least 20% by amount of the first nano-twins copper grains extend across the joining interface, or at least 20% by amount of the second nano-twins copper grains extend across the joining interface.
2. The electrical connecting structure of claim 1 , wherein the first substrate and the second substrate each comprises an oxide layer and a metal layer, wherein the first nano-twins copper layer is positioned on the metal layer of the first substrate, whereas the second nano-twins copper layer is positioned on the metal layer of the second substrate.
3. The electrical connecting structure of claim 1 , wherein a height of each of the first nano-twins copper grains extending across the joining interface is at least 30% of a thickness of the second nano-twins copper layer; or
a height of each of the second nano-twins copper grains extending across the joining interface is at least 30% of a thickness of the first nano-twins copper layer.
4. The electrical connecting structure of claim 3 , wherein the height of each of the first nano-twins copper grains extending across the joining interface ranges from about 0.1 micrometer to about 20 micrometers.
5. The electrical connecting structure of claim 1 , wherein the first nano-twins copper grains and the second nano-twins copper grains are substantially columnar.
6. The electrical connecting structure of claim 1 , wherein a width of each of the first nano-twins copper grains and the second nano-twins copper grains is less than 5 micrometers.
7. The electrical connecting structure of claim 1 , wherein the first nano-twins copper grains and the second nano-twins copper grains are formed and stacked in a direction of [111] crystallographic axis.