Electronic device for ESD protection
A semiconductor device includes a thyristor disposed in a semiconductor body. The thyristor has an anode, a cathode, a first bipolar transistor located on an anode side, and a second bipolar transistor located on a cathode side. The first and second bipolar transistors are nested and connected between the anode and the cathode. A MOS transistor is disposed in the semiconductor body. The MOS transistor is coupled between a collector region and an emitter region of the second bipolar transistor. The MOS transistor has a gate region connected to the cathode via a resistive semiconductor region that incorporates at least a part of a base region of the second bipolar transistor.
1. A method comprising:
providing an electrostatic discharge (ESD) pulse to an electronic device, the electronic device comprising a thyristor having an anode terminal and a cathode terminal, the ESD pulse provided to the anode terminal of the thyristor;
injecting a current at the anode terminal of the thyristor in response to the ESD pulse, the current flowing from the anode terminal to the cathode terminal, a value of the current corresponding to an intrinsic resistance of the thyristor;
self-triggering the thyristor in accordance with a trigger voltage of the thyristor, the trigger voltage corresponding to a length of the electronic device and to the current; and
cancelling the current in response to the self-triggering of the thyristor.
2. The method of claim 1 , wherein the thyristor further comprises:
a first and a second bipolar transistor, the first bipolar transistor coupled to the anode terminal, the second bipolar transistor coupled to the cathode terminal; and
a metal-oxide semiconductor (MOS) transistor coupled to the second bipolar transistor.
3. The method of claim 1 , wherein self-triggering the thyristor comprises the electronic device going into high injection mode.
4. The method of claim 1 , wherein increasing the trigger voltage corresponds to a decrease in the length of the electronic device.
5. The method of claim 1 , wherein decreasing the trigger voltage corresponds to an increase in the length of the electronic device.
6. The method of claim 1 , wherein the ESD pulse is delivered by a human body.
7. A method for an electrostatic discharge (ESD) protection in an integrated circuit comprising a protection circuit, the protection circuit comprising a first and a second electronic device, the method comprising:
providing an ESD pulse to an anode terminal of a thyristor of the first electronic device, the thyristor of the first electronic device having the anode terminal and a cathode terminal;
injecting a current at the anode terminal in response to the ESD pulse, the current flowing from the anode terminal to the cathode terminal, a value of the current corresponding to an intrinsic resistance of the thyristor of the first electronic device; and
self-triggering the thyristor of the first electronic device in accordance with a trigger voltage of the thyristor of the first electronic device, the trigger voltage corresponding to a length of the first electronic device and to the current; and
cancelling the current in response to the self-triggering of the thyristor of the first electronic device.
8. The method of claim 7 , further comprising:
providing a second ESD pulse in to a thyristor of the second electronic device, the thyristor of the second electronic device having a second anode terminal and a second cathode terminal;
injecting a second current at the second anode terminal in response to the second ESD pulse, the second current flowing from the second anode terminal to the second cathode terminal, a value of the second current corresponding to an intrinsic resistance of the thyristor of the second electronic device; and
self-triggering the thyristor of the second electronic device in accordance with a trigger voltage of the thyristor of the second electronic device, the trigger voltage corresponding to a length of the second electronic device and to the second current; and
cancelling the second current in response to the self-triggering of the thyristor of the second electronic device.
9. The method of claim 8 , wherein the integrated circuit further comprises an electronic component coupled to the protection circuit, the method further comprising protecting the electronic component from the first and the second ESD pulse.
10. The method of claim 7 , wherein the anode terminal of the first electronic device is coupled to the cathode terminal of the second electronic device.
11. The method of claim 10 , wherein the anode terminal of the second electronic device is coupled to the cathode terminal of the first electronic device.
12. The method of claim 7 , wherein the protection circuit provides bi-directional ESD protection.
13. The method of claim 7 , wherein an input-output cell of the integrated circuit is within a ring on a periphery of the integrated circuit, wherein the method further comprises protecting the integrating circuit based on an ESD discharge on the periphery of the integrated circuit.
14. A method for electrostatic discharge (ESD) protection, the method comprising:
providing a resistive path between an anode of a thyristor to a cathode of the thyristor;
exposing the anode of the thyristor to an ESD pulse;
injecting current at a reverse capacitive NP junction in a bipolar transistor of the thyristor in response to the exposing to the ESD pulse;
increasing a gate voltage of a metal oxide semiconductor (MOS) transistor based on the current and an intrinsic resistance at a section of the resistive path from a gate of the MOS transistor to the cathode; and
triggering the thyristor into a high injection mode based on a trigger voltage of the thyristor.
15. The method of claim 14 , wherein the trigger voltage of the thyristor is adjusted based on the intrinsic resistance.
16. The method of claim 14 , wherein the trigger voltage of the thyristor is increased by decreasing a length of the section of the resistive path from the gate of the MOS transistor to the cathode.
17. The method of claim 14 , wherein the trigger voltage of the thyristor is decreased by increasing a length of the section of the resistive path from the gate of the MOS transistor to the cathode.
18. The method of claim 14 , wherein the thyristor is coupled to an electronic component, the method further comprising protecting the electronic component by triggering the thyristor into the high injection mode.
19. The method of claim 14 , wherein the ESD pulse is delivered by a human body.
20. The method of claim 14 , wherein increasing the trigger voltage corresponds to a decrease in a length of an electronic device, and wherein decreasing the trigger voltage corresponds to an increase in the length of the electronic device.