Semiconductor device having through substrate vias

1. A semiconductor device comprising:

a semiconductor substrate including a first surface serving as an element formation surface, and a second surface opposite to the first surface;

a through-via penetrating the semiconductor substrate;

an insulating via coating film formed between a sidewall of the through-via and the semiconductor substrate;

an insulating protective film formed on the second surface of the semiconductor substrate; and

an insulating film formed between the protective film and the sidewall of the through-via, wherein

the via coating film, the protective film, and the insulating film are different insulating films from each other, and

the insulating film exists in a substantially same plane as the protective film.

2. The semiconductor device of claim 1 , wherein

an end of the via coating film closer to the second surface is positioned in a substantially same plane as the second surface of the semiconductor substrate, and

the insulating film covers the end of the via coating film closer to the second surface.

3. The semiconductor device of claim 1 , wherein the via coating film is made of an insulating polymer.

4. The semiconductor device of claim 2 , wherein an end of the via coating film closer to the first surface is positioned in a substantially same plane as the first surface of the semiconductor substrate.

5. The semiconductor device of claim 1 , wherein the protective film is made of silicon nitride.

6. The semiconductor device of claim 1 , wherein the insulating film is made of a material more resistant to etching than the via coating film.

7. The semiconductor device of claim 3 , wherein the insulating film is a silicon nitride film, a silicon carbide film, or a silicon oxide film.