Light detecting apparatus
View Patent ↗A light detecting apparatus includes an SOI substrate. In the SOI substrate, a semiconductor layer and a silicon substrate are laminated via an insulating layer. The semiconductor layer has a light receiving unit and a circuit unit formed therein. The light detecting apparatus also includes an interlayer insulating film formed on a first main surface of the SOI substrate. The light detecting apparatus also includes a front surface circuit wiring embedded in the interlayer insulating film. The light detecting apparatus also includes a front surface pseudo-wiring having a grid unit. The grid unit has at least one opening allowing passage of a light of a predetermined wavelength range to the light receiving unit. The light detecting apparatus also includes a rear surface circuit wiring and a rear surface pseudo-wiring formed on a second main surface of the SOI substrate. The light detecting apparatus also includes a penetration circuit wiring that connects the front surface circuit wiring to the rear surface circuit wiring. The light detecting apparatus also includes a penetration pseudo-wiring that electrically connects the front surface pseudo-wiring to the rear surface pseudo-wiring. The light receiving unit is surrounded by the front surface pseudo-wiring, the rear surface pseudo-wiring, and the penetration pseudo-wiring.
1. A light detecting apparatus comprising:
an SOI substrate that has a semiconductor layer and a silicon substrate laminated via an insulating layer, said semiconductor layer having a light receiving unit and a circuit unit formed therein, said SOI substrate having a first main surface and a second main surface;
an interlayer insulating film formed on top of the first main surface of the SOI substrate;
a front surface circuit wiring connected to the light receiving unit or the circuit unit, the front surface circuit wiring being embedded in the interlayer insulating film;
a front surface pseudo-wiring formed on the interlayer insulating film, the front surface pseudo-wiring having a grid unit that defines an opening allowing passage of a light of a predetermined wavelength range to the light receiving unit;
a rear surface circuit wiring provided on top of the second main surface of the SOI substrate;
a rear surface pseudo-wiring provided on top of the second main surface of the SOI substrate;
a penetration circuit wiring that penetrates the SOI substrate to connect the front surface circuit wiring to the rear surface circuit wiring; and
a penetration pseudo-wiring that penetrates at least the SOI substrate to electrically connect the front surface pseudo-wiring to the rear surface pseudo-wiring, wherein the light receiving unit is surrounded by the front surface pseudo-wiring, the rear surface pseudo-wiring, and the penetration pseudo-wiring.
2. The light detecting apparatus of claim 1 , wherein the predetermined wavelength range includes an ultraviolet light range.
3. The light detecting apparatus of claim 2 , wherein the front surface pseudo-wiring further includes a light blocking unit that blocks the light of the predetermined wavelength range.
4. The light detecting apparatus of claim 2 , wherein the penetration pseudo-wiring further penetrates the interlayer insulating film.
5. The light detecting apparatus of claim 3 , wherein the penetration pseudo-wiring has a plurality of column-shaped wirings disposed at intervals sufficient to block electromagnetic radiation noises coming from the outside.
6. The light detecting apparatus of claim 3 , wherein the penetration pseudo-wiring has a wall-shaped wiring disposed to block electromagnetic radiation noise coming from the outside.
7. The light detecting apparatus of claim 3 , wherein the penetration pseudo-wiring connects edge portions of the front surface pseudo-wiring to corresponding edge portions of the rear surface pseudo-wiring.
8. The light detecting apparatus of claim 3 , wherein the penetration circuit wiring is surrounded by the penetration pseudo-wiring.
9. The light detecting apparatus of claim 3 further comprising a sealing unit disposed on the interlayer insulating film to surround the front surface pseudo-wiring, and a transparent substrate bonded to the sealing unit.
10. The light detecting apparatus of claim 3 , wherein a layer thickness of the semiconductor layer is about 30 nm.
11. The light detecting apparatus of claim 1 , wherein the front surface circuit wiring is made from Al or Cu.
12. The light detecting apparatus of claim 11 further comprising a first barrier metal film that covers the front surface circuit wiring.
13. The light detecting apparatus of claim 12 , wherein the first barrier metal film is made from Ti or TiNi.
14. The light detecting apparatus of claim 11 , wherein the front surface pseudo-wiring is made from Al or Cu.
15. The light detecting apparatus of claim 14 further comprising a second barrier metal film that covers the front surface pseudo-wiring.
16. The light detecting apparatus of claim 15 , wherein the second barrier metal film is made from Ti or TiNi.
17. The light detecting apparatus of claim 14 , wherein the rear surface circuit wiring is made from Al or Cu and the rear surface pseudo-wiring is also made from Al or Cu.
18. The light detecting apparatus of claim 17 further comprising a third barrier metal film that covers the rear surface circuit wiring and a fourth barrier metal film that covers the rear surface pseudo-wiring.
19. The light detecting apparatus of claim 18 , wherein each of the third and fourth barrier metal films is made from Ti or TiNi.