Semiconductor device and semiconductor device measuring system

1. A semiconductor device comprising:

a well of a second conductive type formed on or above a semiconductor substrate of a first conductive type;

a first diffusion layer of the second conductive type formed in a surface portion of said well;

a second diffusion layer of the first conductive type formed separately from said first diffusion layer in the surface portion of said well;

first to third first-layer conductive layers formed above said well; and

first to third second-layer conductive layers formed above said first to third first-layer conductive layers,

wherein said first second-layer conductive layer, said first first-layer conductive layer, said first diffusion layer and said well are conductively connected as a first conductive path,

wherein said second second-layer conductive layer, said second first-layer conductive layer, and said second diffusion layer are conductively connected as a second conductive path,

wherein said third second-layer conductive layer, and said third first-layer conductive layer are conductively connected as a third conductive path, and

wherein in measurement of a capacitance between said well and said second diffusion layer, said first second-layer conductive layer is configured to be applied with a voltage, in which a small-amplitude AC voltage is superimposed on a DC bias voltage, from a measuring apparatus, said second second-layer conductive layer is configured to be connected to a ground terminal of the measuring apparatus through an ammeter, and said third second-layer conductive layer is configured to be connected to the ground terminal.

2. The semiconductor device according to claim 1 , wherein at least a part of said second first-layer conductive layer is formed straightly above said second diffusion layer.

3. The semiconductor device according to claim 1 , wherein said third first-layer conductive layer is formed to surround said second first-layer conductive layer planarly.

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

first to third third-layer conductive layers formed above said first to third second-layer conductive layers,

wherein said first third-layer conductive layer is conductively connected with said first second-layer conductive layer,

wherein said second third-layer conductive layer is conductively connected with said second second-layer conductive layer, and

wherein said third third-layer conductive layer is conductively connected with said third second-layer conductive layer.

5. The semiconductor device according to claim 4 , wherein said third first-layer conductive layer is formed to surround said second first-layer conductive layer planarly, and

wherein said third second-layer conductive layer is formed to surround said second second-layer conductive layer planarly.

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

a third diffusion layer of the first conductive type formed separately from said first and second diffusion layers in the surface portion of said well,

wherein said third second-layer conductive layer is conductively connected with said third diffusion layer through said third first-layer conductive layer.

7. The semiconductor device according to claim 6 , wherein said third diffusion layer extends to a portion below said second first-layer conductive layer.

8. The semiconductor device according to claim 6 , wherein said third first-layer conductive layer is formed to surround said second first-layer conductive layer planarly.

9. The semiconductor device according to claim 8 , wherein said third second-layer conductive layer is formed to surround said second second-layer conductive layer planarly.

10. A measuring method of a semiconductor device, comprising:

providing a semiconductor device which comprises:

a well of a second conductive type formed on or above a semiconductor substrate of a first conductive type,

a first diffusion layer of the second conductive type formed in a surface portion of said well,

a second diffusion layer of the first conductive type formed separately from said first diffusion layer in the surface portion of said well,

first to third first-layer conductive layers formed above said well, and

first to third second-layer conductive layers formed above said first to third first-layer conductive layers,

wherein said first second-layer conductive layer, said first first-layer conductive layer, said first diffusion layer and said well are conductively connected as a first conductive path;

wherein said second second-layer conductive layer, said second first-layer conductive layer, and said second diffusion layer are conductively connected as a second conductive path;

wherein said third second-layer conductive layer, and said third first-layer conductive layer are conductively connected as a third conductive path;

applying said first second-layer conductive layer with a voltage, in which a small-amplitude AC voltage is superimposed on a DC bias voltage, from a power supply of a measuring apparatus;

connecting said third second-layer conductive layer to the ground terminal;

connecting said second second-layer conductive layer to a ground terminal of the measuring apparatus through the ammeter; and

measuring a current flowing through said second second-layer conductive layer by an ammeter of said measuring apparatus.

11. The measuring method according to claim 10 , wherein said providing comprises:

a semiconductor device in which at least a part of said second first-layer conductive layer is formed straightly above said second diffusion layer.

12. The measuring method according to claim 10 , wherein said providing comprises:

a semiconductor device in which said third first-layer conductive layer is formed to surround said second first-layer conductive layer planarly.

13. The measuring method according to claim 10 , wherein said providing comprises:

a semiconductor device in which further comprises:

first to third third-layer conductive layers formed above said first to third second-layer conductive layers,

wherein said first third-layer conductive layer is conductively connected with said first second-layer conductive layer,

wherein said second third-layer conductive layer is conductively connected with said second second-layer conductive layer, and

wherein said third third-layer conductive layer is conductively connected with said third second-layer conductive layer.

14. The measuring method according to claim 13 , wherein said providing comprises:

a semiconductor device in which said third first-layer conductive layer is formed to surround said second first-layer conductive layer planarly, and

wherein said third second-layer conductive layer is formed to surround said second second-layer conductive layer planarly.

15. The measuring method according to claim 10 , wherein said providing comprises:

a semiconductor device in which further comprising:

a third diffusion layer of the first conductive type formed separately from said first and second diffusion layers in the surface portion of said well,

wherein said third second-layer conductive layer is conductively connected with said third diffusion layer through said third first-layer conductive layer.

16. The measuring method according to claim 15 , wherein said providing comprises:

a semiconductor device in which said third diffusion layer extends to a portion below said second first-layer conductive layer.

17. The measuring method according to claim 15 , wherein said providing comprises:

a semiconductor device in which said third first-layer conductive layer is formed to surround said second first-layer conductive layer planarly.

18. The measuring method according to claim 17 , wherein said providing comprises:

a semiconductor device in which said third second-layer conductive layer is formed to surround said second second-layer conductive layer planarly.