Semiconductor device structure and method for forming the same

A method for forming a semiconductor device structure, comprising:

• providing a chip structure comprising a substrate and a wiring structure over a first surface of the substrate, wherein the chip structure has a hole penetrating through the wiring structure and extending into the substrate;
• partially removing the wiring structure adjacent to the hole to widen the hole in the wiring structure, wherein the hole has a first enlarged portion and a neck portion after partially removing the wiring structure adjacent to the hole, and the first enlarged portion is wider than the neck portion;
• forming a first seed layer over the wiring structure and in the hole;
• thinning the substrate from a second surface of the substrate until the first seed layer in the hole is exposed, wherein the second surface is opposite to the first surface, and the hole penetrates through the substrate after thinning the substrate;
• and
• partially removing the substrate and the first seed layer in the hole from the second surface;
• and
• forming a second seed layer over the second surface of the substrate and in the hole, wherein the first seed layer has a first portion and a second portion, the first portion is covered by the second seed layer, the second portion is not covered by the second seed layer, and the first portion is thinner than the second portion.

A method for forming a semiconductor device structure, comprising:

• providing a chip structure comprising a substrate and a wiring structure over a first surface of the substrate, wherein the chip structure has a hole penetrating through the wiring structure and extending into the substrate;
• partially removing the wiring structure adjacent to the hole to widen the hole in the wiring structure, wherein the hole has a first enlarged portion and a neck portion after partially removing the wiring structure adjacent to the hole, and the first enlarged portion is wider than the neck portion;
• forming a first seed layer over the wiring structure and in the hole;
• thinning the substrate from a second surface of the substrate until the first seed layer in the hole is exposed, wherein the second surface is opposite to the first surface, and the hole penetrates through the substrate after thinning the substrate;
• and
• forming a second seed layer over the second surface of the substrate and the first seed layer in the hole, wherein the hole has a first shape in a top view of the chip structure, the hole has a second shape in a bottom view of the chip structure, and the first shape is different from the second shape.