Electronic device with a programmable resistive element and a method for blocking a device

• US 8,159,857 B2
• Filed: 09/21/2009
• Issued: 04/17/2012
• Est. Priority Date: 09/21/2009
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Gammel, Berndt, Nirschl, Thomas, Dirscherl, Gerd, Schlazer, Philip
• Primary Examiner(s): NGUYEN, DANG T
• Application Number:
  US12/563,427
• Publication Number:
  US 20110069528A1
• Time in Patent Office: 939 Days
• Field of Search: 365/148, 365/163, 365/189.16, 365/185.03, 365/154, 365/185.33, 365/46, 365/131, 257/528, 438/239, 438/381, 438/95, 438/102
• US Class Current: 365/148
• CPC Class Codes: G11C 13/0004 comprising amorphous/crystalline phase transition cells
• CPC Class Codes: G11C 13/0059 Security or protection circuits or methods
• CPC Class Codes: G11C 13/0069 Writing or programming circuits or methods

Abstract

One or more embodiments relate to an electronic device comprising a circuitry and a programmable resistive element. The programmable resistive element comprises a first and a second state, wherein the programmable resistive element is configured to allow switching from the second state into the first state in response to a signal comprising at least a predefined level. The circuitry is configured to provide signals up the predefined level, wherein the circuitry is configured to provide a switch signal to the programmable resistive element, wherein the switch signal causes switching from the first into the second state.

Claims

1. An electronic device comprising:

a programmable resistive element comprising at least a first state and a second state, wherein the programmable resistive element is configured to allow switching from the second state into the first state in response to a signal comprising at least a predefined level; and

a circuitry for providing signals below the predefined level, wherein the circuitry is configured to provide a switch signal to the programmable resistive element, wherein the switch signal causes switching from the first into the second state,

wherein the circuitry comprises a detector for detecting an unauthorized access of the circuitry and the programmable resistive element is configured to switch into the second state in case the detector detects the unauthorized access.

2. The electronic device of claim 1, wherein the programmable resistive element is configured such that the predefined level comprises a predefined voltage or a predefined current or a predefined polarity or a predefined time, and wherein the circuitry is unable to provide the predefined voltage or the predefined current or the predefined polarity.

3. The electronic device of claim 1, wherein the programmable resistive element further comprises a third state and a memory material such that the second and the third state comprise both high ohmic states of the memory material with different resistances.

4. The electronic device of claim 3, wherein the circuitry is configured to provide signals for switching between the first and the third state.

5. The electronic device of claim 4, wherein the predefined level comprises a predefined voltage, and wherein the programmable resistive element comprises a fourth state comprising a further state of the memory material and wherein the programmable resistive element is configured to allow switching from the fourth state into the first or into the third state in response to a signal comprising at least the predefined level.

6. The electronic device of claim 1, wherein the programmable resistive element comprises a phase change memory element comprising a phase change material.

7. The electronic device of claim 6, wherein the programmable resistive element further comprises a third state such that at least the second state comprises a mixture of an amorphous phase and a first crystalline phase and the third state comprises a mixture of an amorphous phase and at least a second crystalline phase with different resistance than the first state, or

at least the second state comprises crystalline phases of the phase change material with different resistance than the first state.

8. The electronic device of claim 6, wherein the phase change material comprises a chalcogenide or a chalcogenide alloy.

9. The electronic device of claim 1, wherein the programmable resistive element comprises a T-cell.

10. The electronic device of claim 1, wherein the programmable resistive element comprises a funnel like shape.

11. The electronic device of claim 1, wherein the circuitry is configured to provide only signals below the predefined level.

12. The electronic device of claim 1, wherein the programmable resistive element comprises a metal oxide.

13. An electronic device comprising:

a programmable resistive element comprising at least a first state and a second state; and

a circuitry for providing a switch signal to switch the programmable resistive element from the first state into the second state,

wherein the circuitry is unable to provide a signal to switch the programmable resistive element from the second state into the first state,

wherein the programmable resistive element further comprises a third state, the first state and the third state are reversible states in that the circuitry is able to provide signals to switch between the first state and the third state, and

wherein the programmable resistive element comprises a memory material such that the first state, the second state and the third state comprise different resistances, wherein the resistance of the third state is between the resistance of the first state and the resistance of the second state, and wherein the second state comprise a highest resistance.

14. The electronic device of claim 13, wherein the memory material is a phase change material, wherein the first state comprises a crystalline phase, and wherein both, the second state and the third state comprise different amorphous phases or different mixtures of crystalline phases with amorphous phases.

15. The electronic device of claim 13, wherein the programmable resistive element comprises an asymmetric phase change memory cell.

16. An electronic device comprising:

a programmable resistive element comprising at least a first state and a second state; and

a circuitry for providing a switch signal to switch the programmable resistive element from the first state into the second state,

wherein the circuitry is unable to provide a signal to switch the programmable resistive element from the second state into the first state, and

wherein the programmable resistive element further comprises a fourth state, and wherein the circuitry is configured to provide a further switch signal to switch from the first state into the fourth state, wherein the fourth state is irreversible in that the circuitry is unable to provide a signal to switch from the fourth state into the first state or into the third state.

17. The electronic device of claim 16, wherein the programmable resistive element comprises a memory material such that the first state, the second state, the third state, and the fourth state comprise different resistances, wherein the fourth state comprise a lowest resistance and the second state a highest resistance, and wherein the first state comprise a lower resistance than the third state.

18. The electronic device of claim 17, wherein the memory material is a phase change material, wherein both, the first state and the fourth state comprise different crystalline phases, and wherein both, the second state and the third state comprise different amorphous phases.

19. An electronic device comprising:

an asymmetric phase change element comprising at least a first, a second and a third state, wherein the phase change element is configured to allow switching from the at least third state into the first or into the second state in response to a signal comprising at least a predefined level; and

a circuitry configured to provide a first and a second signal to the asymmetric phase change element, wherein the first signal causes switching between the first and the second state and the second signal causes switching from the first or from the second state into the third state,

and wherein the circuitry is configured to provide signals up to a maximum level, which is below the predefined level.

20. The electronic device of claim 19, wherein the circuitry is configured to provide a device individual bit stream, and wherein the circuitry is configured to block providing the bit stream in case the asymmetric phase change memory element is within the third state.

21. The electronic device of claim 20, wherein the circuitry comprises an integrated circuit realizing a physically uncloneable function for providing the device specific bit stream.

22. The electronic device of claim 19, wherein the circuitry is configured such that the circuitry is damaged in case a signal of the predefined level is applied.

23. The electronic device of claim 19, further comprising a detector for detecting an unauthorized attempt to access the circuitry and wherein the asymmetric phase change element is configured to switch into the third state in case the detector detects the unauthorized attempt.

24. An apparatus for blocking an electronic device comprising:

a means for switching between at least a first, a second, and a third state, wherein the means for switching is configured to switch from the at least third state into the first or into the second state in response to a signal comprising at least a predefined level; and

a means for processing configured to provide a first and a second signal to the means for switching, wherein the first signal causes switching between the first and the second state, and the second signal causes switching from the first or from the second state into the at least third state,

and wherein the means for processing is configured to provide signals up to a maximum level, which is below the predefined level.

25. The apparatus of claim 24, further comprising a means for detecting an attempt of unauthorized access of the means for processing, wherein the means for switching is configured to switch in case the attempt is detected from the first or from the second state into the at least third state.

26. A method for blocking an electronic device comprising an asymmetric programmable resistive element and a circuitry, wherein the asymmetric programmable resistive element comprises a first, a second and at least a third state, comprising:

switching between the first, the second, and the at least third state, wherein switching from the third state into the first or into the second state is performed in response to a signal comprising at least a predefined level; and

providing a first and a second signal by the circuitry, wherein the first signal causes switching between the first and the second state and the second signal causes switching from the first or from the second state into the third state,

wherein the circuitry is configured to provide signals up to a maximum level, which is below the predefined level.

27. The method of claim 26, wherein the programmable resistive element is an asymmetric phase change memory element.

28. The method of claim 26, further comprising detecting an attempt of unauthorized access of the circuitry and a switching from the first or from the second state into the third state.