Interconnection structure of package structure and method of forming the same

1. A package structure comprising:

a first semiconductor device comprising a first semiconductor substrate and a first electronic device, the first semiconductor device having a first side and a second side opposite to the first side, wherein the first electronic device is disposed on the first side, and wherein the first semiconductor device has a via-hole formed completely through the first semiconductor device, wherein the via-hole has a first opening adjacent to the first side;

an interconnection structure disposed in the first semiconductor device, wherein the interconnection structure comprises:

a via structure disposed in the via-hole without exceeding the first opening;

a first pad disposed on the first side of the first semiconductor device and covering the via-hole, wherein the first pad is adjoined to the via structure and is electrically connected to the first electronic device, and the first pad and the first electronic device are disposed on the same level of the first semiconductor device; and

a second semiconductor device vertically integrated with the first semiconductor device, wherein the second semiconductor device comprises a second electronic device electrically connected with the first electronic device.

2. The package structure as claimed in claim 1 , wherein the first semiconductor substrate comprises a die or a wafer, and the second semiconductor device comprises a second semiconductor substrate, wherein the second semiconductor substrate comprises a die or a wafer.

3. The package structure as claimed in claim 1 , wherein the second semiconductor device has a third side and a fourth side opposite to the third side, and wherein the second semiconductor device comprises a second semiconductor substrate adjacent to the fourth side and at least part of the second electronic device is adjacent to the third side.

4. The package structure as claimed in claim 3 , wherein the first side of the first semiconductor device and the third side of the second semiconductor device face each other.

5. The package structure as claimed in claim 3 , wherein the second side of the first semiconductor device and the third side of the second semiconductor device face each other.

6. The package structure as claimed in claim 3 , wherein the first side of the first semiconductor device and the fourth side of the second semiconductor device face each other.

7. The package structure as claimed in claim 3 , wherein the second side of the first semiconductor device and the fourth side of the second semiconductor device face each other.

8. The package structure as claimed in claim 1 , wherein at least one of the first electronic device and the second electronic device is a transistor.

9. The package structure as claimed in claim 1 , further comprising:

a carrier substrate, wherein the first semiconductor device and the second semiconductor device are stacked on the carrier substrate, and the first electronic device and the second electronic device are electrically connected to the carrier substrate through the interconnection structure.

10. The package structure as claimed in claim 1 , wherein a portion of the first pad extends into the via-hole.