Disclosed circuit arrangements include a physically unclonable function (PUF) entropy source having passive circuit elements and active circuit elements. A first die has one or more metal layers and an active layer, and the passive circuit elements are disposed in the one or more metal layers. A second die has one or more metal layers and an active layer. The active circuit elements are coupled to the passive circuit elements and are disposed in the active layer of the second die, and the first die and the second die are in a stacked structure. The stacked structure has the one or more metal layers of the first die disposed between the active layer of the first die and the active layer of the second die.

Disclosed circuit arrangements include a physically unclonable function (PUF) entropy source having passive circuit elements and active circuit elements. A first die has one or more metal layers and an active layer, and the passive circuit elements are disposed in the one or more metal layers. A second die has one or more metal layers and an active layer. The active circuit elements are coupled to the passive circuit elements and are disposed in the active layer of the second die, and the first die and the second die are in a stacked structure. The stacked structure has the one or more metal layers of the first die disposed between the active layer of the first die and the active layer of the second die.

A memory device includes an anti-fuse memory cell that randomly presents either a first logic state or a second logic state. The memory cell is formed on a frontside of a substrate and at least includes a first programming transistor that is formed in a first one of a plurality of metallization layers disposed over the frontside and gated by a first programming word line, and a first reading transistor that is formed in a second one of the plurality of metallization layers disposed over the frontside or along a major surface on the frontside, coupled to the first programming transistor and a first bit line in series, and gated by a first reading word line.

A memory device includes an anti-fuse memory cell that randomly presents either a first logic state or a second logic state. The memory cell is formed on a frontside of a substrate and at least includes a first programming transistor that is formed in a first one of a plurality of metallization layers disposed over the frontside and gated by a first programming word line, and a first reading transistor that is formed in a second one of the plurality of metallization layers disposed over the frontside or along a major surface on the frontside, coupled to the first programming transistor and a first bit line in series, and gated by a first reading word line.

Integrated circuit (IC) protections that prevent exposure or examination of integrated circuitry through backside analysis include a layer or mesh of an electrically conductive, electromagnetic radiation blocking material disposed over a backside of an IC device to prevent backside analysis. An electrically conductive conduit couples the material to a node of the integrated circuitry to provide a signal and/or voltage reference to the node through the layer/mesh. If the layer/mesh is tampered with, the integrated circuitry loses the voltage reference or signal thereby disabling the integrated circuitry. The IC device may include detection circuitry to monitor the node and to generate an alert and/or disable the circuitry upon tampering. The IC device may further include a support substrate, where a substrate between the material/mesh and the integrated circuitry is sufficiently thin that the IC device would be mechanically weak if the support substrate were removed.

Integrated circuit (IC) protections that prevent exposure or examination of integrated circuitry through backside analysis include a layer or mesh of an electrically conductive, electromagnetic radiation blocking material disposed over a backside of an IC device to prevent backside analysis. An electrically conductive conduit couples the material to a node of the integrated circuitry to provide a signal and/or voltage reference to the node through the layer/mesh. If the layer/mesh is tampered with, the integrated circuitry loses the voltage reference or signal thereby disabling the integrated circuitry. The IC device may include detection circuitry to monitor the node and to generate an alert and/or disable the circuitry upon tampering. The IC device may further include a support substrate, where a substrate between the material/mesh and the integrated circuitry is sufficiently thin that the IC device would be mechanically weak if the support substrate were removed.

A physically unclonable function (PUF) device comprises a plurality of conductors, at least some of which are arranged so that they interact electrically and/or magnetically with one another. A media surrounds at least a portion of each of the conductors, and circuitry is configured for applying an electrical challenge signal to at least one of the conductors and for receiving an electrical output from at least one of the other conductors to generate an identifying response to the challenge signal that is unique to the device. The media comprises a plurality of interactive regions, the interactive regions having an electrical and/or magnetic response characteristic which is permanently altered in response to a predetermined environmental event, and the identifying response is altered with the response characteristic.

A method for producing an individualization zone of a microelectronic chip having a first and a second electrical track level and an interconnection level including vias, includes providing the first level and a dielectric layer, forming an etching mask on the dielectric layer, randomly depositing particles on the etching mask, and forming a lithographic layer having opening patterns. The mask layer is etched through opening patterns to form mask openings, then the dielectric layer is etched through the mask openings, so as to obtain functional via openings and degraded via openings. The via openings are filled so as to form the vias of the interconnection level, the vias including functional vias at the functional openings and malfunctional vias at the degraded openings.

A method for producing an individualization zone of a microelectronic chip having a first and a second electrical track level and an interconnection level including vias, includes providing the first level and a dielectric layer, forming an etching mask on the dielectric layer, randomly depositing particles on the etching mask, and forming a lithographic layer having opening patterns. The mask layer is etched through opening patterns to form mask openings, then the dielectric layer is etched through the mask openings, so as to obtain functional via openings and degraded via openings. The via openings are filled so as to form the vias of the interconnection level, the vias including functional vias at the functional openings and malfunctional vias at the degraded openings.

A package comprising a first substrate, a first integrated device coupled to the first substrate, a second substrate coupled to the first substrate through a first plurality of solder interconnects such that the first integrated device is located between the first substrate and the second substrate, wherein the second substrate includes a first surface and a second surface, an electrical device coupled to a second surface of the second substrate such that the electrical device is located between the first substrate and the second substrate, and an encapsulation layer coupled to the first substrate and the second substrate. The encapsulation layer is located between the first substrate and the second substrate. The encapsulation layer encapsulates the first integrated device and the electrical device.