Method for layout design and structure with inter-layer vias

1. A computer implemented layout method, the method comprising:

bundling, for purposes of placement, a circuit cell and an inter-layer via together as an integral unit;

placing the integral unit of the circuit cell and the inter-layer via in a first device layer of an integrated circuit (IC) design; and

placing a metal pattern in a second device layer of the IC design,

wherein the placing the integral unit of the circuit cell and the inter-layer via forms a direct electrical connection channel between the circuit cell and the metal pattern, and at least one of the above placing operations is performed using a layout generating machine.

2. The method of claim 1 , wherein the circuit cell includes at least one active component.

3. The method of claim 1 , wherein the circuit cell and the inter-layer via are placed in a location within the first device layer of the IC design, and wherein the location within the first device layer corresponds to a location within the second device layer.

4. The method of claim 3 , further comprising placing a power supply line in the first device layer to the circuit cell.

5. The method of claim 3 , wherein the first device layer is placed with a first power supply line and the second device layer is placed with a second power supply line.

6. The method of claim 1 , wherein the circuit cell includes a voltage level shifter.

7. The method of claim 1 , wherein the inter-layer via is configured to carry a power supply voltage, an analog signal or a logic signal.

8. The method of claim 1 , further comprising:

placing a plurality of circuits in the IC design, at least one of the plurality of circuits being connected to the circuit cell;

evaluating routing and timing violations of the IC design; and

relocating the circuit cell and the metal pattern to meet a predetermined routing rule and timing goal.

9. The method of claim 1 , wherein the IC structure is a monolithic three dimensional IC (3DIC) structure.

10. A computer implemented layout method, the method comprising:

bundling, for purposes of placement, a circuit cell and the inter-layer via together as an integral unit;

placing the integral unit of the circuit cell and the inter-layer via in a first device layer of an integrated circuit (IC) design, the first device layer including at least one active component;

placing a connection between the circuit cell and a power supply rail within the first device layer; and

placing a metal pattern in a second device layer of the IC design, the second device layer including a second power supply voltage connection,

wherein the placing the integral unit of the circuit cell and the inter-layer via and the metal pattern forms a direct electrical connection channel between the first device layer and the second device layer;

evaluating routing and timing violations of the IC design; and

relocating the circuit cell along with the metal pattern to meet a predetermined routing rule and timing goal, wherein at least one of the above placing operations is performed using a layout generating machine.

11. The method of claim 10 , wherein the circuit cell includes a voltage level shifter.

12. The method of claim 10 , wherein the inter-layer via is configured to carry a power supply voltage.

13. The method of claim 10 , wherein the inter-layer via is configured to carry an analog or a logic signal.

14. The method of claim 10 , further comprising:

placing a plurality of circuits in the IC design, at least one of the plurality of circuits being connected to the circuit cell.

15. The method of claim 10 , further comprising

bundling, as an integral unit for purposes of placement, the inter-layer via and the circuit cell, which includes the voltage level shifter; and

wherein the placing a circuit cell and an inter-layer via places the integral unit of the inter-layer via and the circuit cell, which includes the voltage level shifter.

16. A three dimensional integrated circuit (3DIC) structure comprising:

a circuit cell in a first device layer of the 3DIC structure, the circuit cell includes a voltage level shifter;

a metal pattern in a second device layer of the 3DIC structure; and

an inter-layer via connecting the voltage level shifter of the circuit cell in the first device layer at a predetermined location and connecting the metal pattern in the second device layer of the 3DIC structure, the predetermined location being within a cell boundary of the circuit cell in the first device layer of the 3DIC structure;

wherein a footprint of the inter-layer via is at least one order of magnitude smaller than a footprint of the circuit cell.

17. The integrated circuit of claim 16 , wherein the predetermined location within the first device layer corresponds to a location within the second device layer.

18. The integrated circuit of claim 16 , wherein the inter-layer via is configured to carry a power supply voltage, an analog signal, or a logic signal.

19. The integrated circuit of claim 16 , wherein the inter-layer via is vertical or substantially vertical to the first device layer and the second device layer.

20. The integrated circuit of claim 16 , wherein:

a footprint of the inter-layer via is two orders of magnitude smaller than a footprint of a through-silicon-via.