Semiconductor device and method for production of semiconductor device
A semiconductor device with a connection pad in a substrate, the connection pad having an exposed surface made of a metallic material that diffuses less readily into a dielectric layer than does a metal of a wiring layer connected thereto.
1. A semiconductor device comprising:
a first semiconductor substrate;
a first wiring layer formed on the first semiconductor substrate, wherein the first wiring layer includes a first pad and a first insulating film, wherein the first wiring layer comprises a diffusion preventing layer, wherein the first pad and the diffusion preventing layer comprise at least a section of a first surface of the first wiring layer;
a second semiconductor substrate;
a second wiring layer formed on the second semiconductor substrate, wherein the second wiring layer includes a second pad and a second insulating film;
wherein the first pad contacts the second pad,
wherein the first surface of the first wiring layer is adjacent to a surface of the second wiring layer, and
wherein a first portion of the diffusion preventing layer forms a portion of the first surface of the first wiring layer and contacts the second wiring layer.
2. The semiconductor device of claim 1 , wherein the first portion of the diffusion preventing layer contacts the second insulating film.
3. The semiconductor device of claim 2 , wherein a second portion of the diffusion preventing layer forms a second surface opposite to the first surface of the first wiring layer and contacts the first insulating film.
4. The semiconductor device of claim 3 , wherein a surface of the first pad contacts the diffusion preventing layer and the first insulating film and extends in a direction perpendicular to the first surface of the first wiring layer.
5. The semiconductor device of claim 1 , wherein the diffusion preventing layer includes at least one of Si, N, O, and C.
6. The semiconductor device of claim 1 , wherein the diffusion preventing layer includes SiN or SiOC.
7. The semiconductor device of claim 1 , wherein the second pad is partially covered by a barrier metal.
8. The semiconductor device of claim 7 , wherein the barrier metal covers at least a portion two surfaces of the second pad extending in a direction perpendicular to the first surface.
9. The semiconductor device of claim 7 , wherein the barrier metal covers at least a portion of a surface extending in a direction parallel to the first surface.
10. The semiconductor device of claim 7 , wherein the barrier metal includes at least one of Ti, N, and Ta.
11. The semiconductor device of claim 10 , wherein the barrier metal includes TiN or TaN.
12. The semiconductor device of claim 7 , wherein a portion of the barrier metal contacts the first pad.
13. The semiconductor device of claim 7 , wherein the first pad is partially covered by the barrier metal.
14. The semiconductor device of claim 1 , wherein a surface of the second pad is exposed through the diffusion preventing layer.
15. The semiconductor device of claim 1 , wherein the diffusion preventing layer prevents metal of the first pad from diffusing into a dielectric film of the second wiring layer.
16. The semiconductor device of claim 1 , wherein each of the first pad and the second pad includes at least one of Cu, Au, Ag, Al, Ta, Ti, W, Sn, Mo, Ni, In, Co and an alloy of any of Cu, Au, Ag, Al, Ta, Ti, W, Sn, Mo, Ni, In, and Co.
17. The semiconductor device of claim 1 , wherein a width of the second pad in a direction parallel to the first surface of the first wiring layer is greater than a width of the first pad in the direction parallel to the first surface.
18. The semiconductor device of claim 1 , wherein a width of the second pad in a direction parallel to the first surface of the first wiring layer is equal to a width of the first pad in the direction parallel to the first surface.
19. The semiconductor device of claim 1 , wherein a first one of the first semiconductor substrate and the second semiconductor substrate includes an imaging device, and a second one of the first semiconductor substrate and the second substrate includes at least one of a memory device and a logic device.