Semiconductor device which can transmit electrical signals between two circuits

1. A semiconductor device comprising:

a first substrate;

a second substrate;

a multi-level interconnect structure provided over the first substrate;

a first inductor provided in the multi-level interconnect structure so as to surround all transistors provided over the first substrate in a plan view; and

a second inductor provided in the multi-level interconnect structure so as to surround all the transistors provided over the first substrate in the plan view,

wherein the second inductor is provided over the first inductor,

wherein the first substrate is provided with a first circuit region containing a first circuit,

wherein the second substrate is provided with a second circuit region containing a second circuit,

wherein the first inductor is provided in the multi-level interconnect structure so as to include the first circuit region,

wherein the second inductor is provided in the multi-level interconnect structure so as to include the first circuit region, and

wherein one of the first inductor and the second inductor is connected to the first circuit, and the other of the first inductor and the second inductor is connected to the second circuit.

2. The semiconductor device according to claim 1 , wherein the first inductor and the second inductor differ from each other in reference voltage.

3. The semiconductor device according to claim 1 ,

wherein the multi-level interconnect structure includes a first interconnect layer, an insulation layer placed on the first interconnect layer, and a second interconnect layer placed on the insulation layer,

wherein the first inductor is provided on the first interconnect layer, and

wherein the second inductor is provided on the second interconnect layer.

4. The semiconductor device according to claim 1 , wherein the first inductor and the second inductor overlap each other in the plan view.

5. The semiconductor device according to claim 3 , wherein spacing between the first inductor and the second inductor is smaller than diameters of the first inductor and the second inductor.

6. A semiconductor device, comprising:

a first substrate, provided with a first circuit region containing a first circuit;

a second circuit region, on the first substrate, containing a second circuit;

a multi-level interconnect structure provided over the first substrate;

a first inductor provided in the multi-level interconnect structure so as to surround all transistors provided over the first substrate in a plan view; and

a second inductor provided in the multi-level interconnect structure so as to surround all the transistors provided over the first substrate in the plan view,

wherein the second inductor is provided over the first inductor,

wherein the first circuit region and the second circuit region are insulated from each other,

wherein the first inductor is provided in the multi-level interconnect structure so as to include the first circuit region,

wherein the second inductor is provided in the multi-level interconnect structure so as to include the first circuit region, and

wherein one of the first inductor and the second inductor is connected to the first circuit and the other of the first inductor and the second inductor is connected to a second circuit.

7. The semiconductor device according to claim 6 , wherein the first circuit is a transmit circuit including a transmit driver circuit connecting to the first inductor.

8. The semiconductor device according to claim 7 , wherein one end of the first inductor is connected to the transmit driver circuit and another end of the first inductor is connected to a power wire or a ground wire.

9. The semiconductor device according to claim 6 , wherein the second circuit includes a receive circuit and a receive driver circuit.

10. The semiconductor device according to claim 9 , further comprising:

wiring which connects the second inductor and the second circuit with each other.

11. The semiconductor device according to claim 10 , wherein the first circuit region is located inside an area surrounded by the first inductor and the second inductor.

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

pads provided in a top of the multi-level interconnect structure,

wherein all the pads are surrounded by the first inductor and the second inductor in the plan view.

13. The semiconductor device according to claim 12 , wherein the pads are connected to the transistors.

14. The semiconductor device according to claim 13 , wherein the pads are connected to other regions across the second inductor.