Semiconductor device and semiconductor memory devices having first, second, and third insulating layers

1. A semiconductor device comprising:

a semiconductor substrate;

a first insulating layer over a surface of the semiconductor substrate;

first and second contact plugs each including side and upper surfaces, the side surfaces of the first and second contact plugs being surrounded by the first insulating layer, the upper surfaces of the first and second contact plugs being substantially on the same plane with an upper surface of the first insulating layer;

a second insulating layer over the first insulating layer;

a first conductive layer including a bottom portion on the first contact plug and a side portion surrounded by the second insulating layer;

a third insulating layer completely covering over the first conductive layer; and

a second conductive layer on the second contact plug, a part of a side surface of the second conductive layer being surrounded by both the second and third insulating layers.

2. The semiconductor device according to claim 1 , further comprising:

a capacitor including the second conductive layer as a lower electrode.

3. The semiconductor device according to claim 2 , further comprising:

a fourth insulating layer over the second conductive layer; and

a third conductive layer facing to the second conductive layer via the forth insulating layer.

4. The semiconductor device according to claim 3 , wherein the capacitor includes the fourth insulating layer as a capacitor insulator and includes the third conductive layer as an upper electrode.

5. The semiconductor device according to claim 1 , wherein the first conductive layer comprises a barrier layer and a wiring layer, the barrier layer having a U-shape that filled with the wiring layer.

6. The semiconductor device according to claim 5 , wherein the barrier layer is in contact with the first contact plug.

7. The semiconductor device according to claim 1 , further comprising:

a first diffusion layer connected to the first contact plug on the surface of the semiconductor substrate; and

a second diffusion layer connected to the second contact plug on the surface of the semiconductor substrate.

8. The semiconductor device according to claim 7 , further comprising:

a third contact plug between the second contact plug and the second diffusion layer.

9. The semiconductor device according to claim 8 , wherein the third contact plug is in contact with the second diffusion layer.

10. The semiconductor device according to claim 8 , further comprising:

a buffer layer between the second contact plug and the third contact plug.

11. The semiconductor device according to claim 8 , wherein the buffer layer is disposed between the first contact plug and the first diffusion layer.

12. A semiconductor memory device comprising:

a semiconductor substrate comprising a memory cell array circuitry area and a peripheral circuitry area laterally of the memory cell array circuitry area;

a first insulating layer over the memory cell array circuitry area and the peripheral circuitry area;

first and second contact plugs each including side and upper surfaces, the side surfaces of the first and second contact plugs being surrounded by the first insulating layer, the upper surfaces of the first and second contact plugs being substantially on the same plane with an upper surface of the first insulating layer, the first contact plug being within the peripheral circuitry area, the second contact plug being within the memory cell array circuitry area;

a second insulating layer over the first insulating layer within the memory cell array circuitry area and the peripheral circuitry area;

a first conductive layer within the peripheral circuitry area, the first conductive layer including a bottom portion on the first contact plug and a side portion surrounded by the second insulating layer;

a third insulating layer over the first conductive layer within the memory cell array circuitry area and the peripheral circuitry area; and

a second conductive layer within the memory cell array circuitry area, the second conductive layer being on the second contact plug, a part of a side surface of the second conductive layer being surrounded by both the second and third insulating layers.

13. The semiconductor memory device according to claim 12 , wherein the third insulating layer completely covers over the first conductive layer within the peripheral circuitry area.

14. A semiconductor memory device comprising:

a first insulating layer within a memory cell array circuitry area and a peripheral circuitry area laterally of the memory cell array circuitry area;

first and second contact plugs each including side surface surrounded by the first insulating film, the first contact plug being within the peripheral circuitry area, the second contact plug being within the memory cell array circuitry area;

a second insulating layer over the first insulating layer within the memory cell array circuitry area and the peripheral circuitry area;

a first conductive layer within the peripheral circuitry area, the first conductive layer being on the first contact plug and having a side surface surrounded by the second insulating layer;

a third insulating layer over the second insulating layer within the memory cell array circuitry area and the peripheral circuitry area, the third insulating layer being over the first conductive layer within the peripheral circuitry area; and

a second conductive layer within the memory cell array circuitry area, the second conductive layer being on the second contact plug, a part of the second conductive layer surrounded by both the second and third insulating layers.

15. The semiconductor memory device according to claim 14 , wherein the third insulating layer completely covers over the first conductive layer within the peripheral circuitry area.

16. A semiconductor device comprising:

a first insulating layer;

first and second contact plugs each including side surface surrounded by the first insulating film;

a second insulating layer over the first insulating layer;

a first conductive layer on the first contact plug and having a side surface surrounded by the second insulating layer;

a third insulating layer completely covering over the second insulating layer and completely covering over the first conductive layer; and

a second conductive layer on the second contact plug, a part of the second conductive layer surrounded by both the second and third insulating layers.