Method of forming a semiconductor device having through silicon vias
In the semiconductor device, a semiconductor substrate has first and second surfaces. A circuitry layer is formed over the first surface and a first insulating layer is further formed over the circuitry layer. A second insulating layer including a first insulating element is formed over the second surface. A third insulating layer including a second insulating element different from the first insulating element of the second insulating layer is formed over the second surface with an intervention of the second insulating layer therebetween. A penetration electrode penetrates through the semiconductor substrate, the circuitry layer, the first insulating layer, the second insulating layer and the third insulating layer.
1. A method of forming a semiconductor device, the method comprising:
providing a semiconductor substrate having first and second surfaces opposed to each other;
forming a plurality of transistors on the first surface of the semiconductor substrate;
forming a first interlayer dielectric film to cover the plurality of transistors and the first surface of the semiconductor substrate;
forming a first back insulating layer on the second surface of the semiconductor substrate, the first back insulating layer comprising a first insulating element;
forming a second back insulating layer in direct contact with the first back insulating layer, the second back insulating layer comprising a second insulating element different from the first insulating element;
forming an opening on the second back insulating layer and sequentially etching the first back insulating layer and the semiconductor substrate through the opening to form a substrate through hole; and
forming a through silicon via in the substrate through hole, wherein the through silicon via has an exposed end face protruding out from the second back insulating layer, wherein forming the through silicon via comprises sequentially forming a seed layer and a through silicon via body.
2. The method of claim 1 , wherein the through silicon via body is formed by copper electrolytic plating.
3. The method of claim 1 , further comprising:
forming a plurality of wiring layers on the first interlayer dielectric film, the plurality of wiring layers including a lowermost wiring layer in direct contact with the first interlayer dielectric film; and
wherein the seed layer is formed in direct contact with the lowermost wiring layer.
4. The method of claim 3 , wherein etching to form a substrate through hole comprises etching into the first interlayer dielectric film to expose the lowermost wiring layer.
5. The method of claim 1 , further comprising:
forming an insulating ring in the semiconductor substrate such that the through silicon via is surrounded by the insulating ring.
6. The method of claim 5 , wherein the through silicon via and the insulating ring have an intervention ring of silicon substrate therebetween.
7. The method of claim 5 , wherein the insulating ring is formed before the formation of the through silicon via.
8. The method of claim 1 , wherein etching to form the substrate through hole comprises etching into the first interlayer dielectric film.
9. The method of claim 1 , wherein the first back insulating layer is formed directly on the substrate.
10. The method of claim 1 , further comprising:
forming an insulating ring in the semiconductor substrate such that the through silicon via is surrounded by the insulating ring; and
forming the first back insulating layer to cover the insulating ring.
11. The method of claim 10 , wherein forming the insulating ring comprising:
forming a ring-shaped groove in the semiconductor substrate;
embedding the ring-shaped groove with insulating film to form the insulating ring; and
exposing an end face of the insulating ring from the second surface of the semiconductor substrate.
12. The method of claim 1 , wherein etching the first back insulating layer and the semiconductor substrate to form the substrate through hole is performed through an entire circumference of the opening on the second back insulating layer.
13. The method of claim 1 , where forming the first back insulating layer comprises forming the first back insulating layer on the second surface of the semiconductor substrate after forming the first interlayer dielectric film.
14. The method of claim 1 , forming the opening on the second back insulating layer comprises forming the opening only on the second back insulating layer and sequentially etching the first back insulating layer and the semiconductor substrate only through the opening to form the substrate through hole.
15. The method of claim 1 , where forming the second back insulating layer comprises forming the second back insulating layer over only the second surface of the semiconductor substrate and in direct contact with the first back insulating layer.
16. The method of claim 1 , further comprising thinning the semiconductor substrate from the second surface before forming the first back insulating layer on the second surface of the semiconductor substrate.