Active shield structure

1. A device comprising:

an array of active shield coil structures, wherein each active shield coil structure comprises:

a first coil-shaped spiral structure for an active shield; and

a second coil-shaped spiral structure that is wound in-between windings of the first coil-shaped spiral structure, wherein:

the first coil-shaped spiral structure provides for a coil-based electro-magnetic (EM) shield as a counter-measure circuit for protecting an underlying circuit, and

wherein the array of the active shield coil structures is arranged in a grid pattern.

2. The device of claim 1 , wherein:

the array is arranged in the grid pattern across a same layer at least one of covering or overlaying the underlying circuit; and

the active shield comprises a conductive interconnect line for transceiving a characteristic code between a transmit node and a receive node, and wherein the active shield is disposed such that a plurality of the conductive interconnect lines covers an area of sensitive circuitry at routing levels and device levels disposed below the active shield.

3. The device of claim 1 , wherein:

the first coil-shaped spiral structure is formed of a first conductive wire, and wherein the second coil-shaped spiral structure is formed of a second conductive wire that is separate from the first conductive wire, and wherein the first coil-shaped spiral structure and the second coil-shaped spiral structure are formed in a same layer.

4. The device of claim 3 , wherein a width of the first conductive wire is greater than a width of the second conductive wire.

5. The device of claim 1 , wherein the first coil-shaped spiral structure comprises a first continuous coil-shaped spiral structure.

6. The device of claim 1 , wherein the first coil-shaped spiral structure is coupled to a signal generator that provides a signal for generating an electro-magnetic (EM) field across the active shield.

7. The device of claim 6 , wherein the first coil-shaped spiral structure and the second coil-shaped spiral structure are disposed in a same layer that overlies a cryptographic circuit, and wherein a frequency of the signal is aligned or harmonic with an operating frequency of the cryptographic circuit.

8. The device of claim 7 , wherein the signal transmitted into the first coil-shaped spiral structure has the same frequency and phase as the digital clock driving the underlying circuit.

9. The device of claim 1 , wherein the first coil-shaped spiral structure and the second coil-shaped spiral structure provide for a combined coil-based active tamper protection shield as a counter-measure circuit for protecting an underlying circuit from unauthorized attempts to access signals or physically modify underlying circuitry.

10. The device of claim 1 , wherein the first coil-shaped spiral structure provides the counter-measure circuit for protecting the underlying circuit from unauthorized access via an EM side-channel attack.

11. The device of claim 1 , wherein:

the second coil-shaped spiral structure is coupled directly to a single fixed potential,

the fixed potential is a ground supply, and wherein the second coil-shaped spiral structure operates as a ground supply line that is coupled directly to the ground supply, and

the fixed potential is configured to transfer power to the underlying circuit.

12. The device of claim 1 , wherein:

the second coil-shaped spiral structure is coupled directly to a single fixed potential,

the fixed potential is a voltage supply, and wherein the second coil-shaped spiral structure operates as a voltage supply line that is coupled directly to the voltage supply, and

the fixed potential is configured to transfer power to the underlying circuit.

13. The device of claim 1 , wherein:

the array of active shield coil structures is arranged in a two-dimensional array, and

the two-dimensional array comprises a plurality of columns and a plurality of rows.

14. The device of claim 13 , wherein:

each active shield coil structure of the array is configured with a respective transmit line and a respective return line to transmit an electro-magnetic (EM) signal therebetween.

15. The device of claim 13 , wherein:

adjacent active shield coil structures of the array are configured to be driven with different current directions, and

the different current directions minimize a cancelation of one or more electro-magnetic (EM) fields.

16. The device of claim 1 , wherein a respective underpass line is configured to couple a respective coil-shaped spiral structure to a respective return line.

17. The device of claim 16 , wherein the respective underpass line is formed on a different metal layer than a metal layer used to form the respective coil-shaped spiral structure.

18. The device of claim 17 , further comprising: one or more vias configured to couple the respective underpass line to the respective coil-shaped spiral structure and the respective return line.