Backside fib probing detector in a forward and reverse body biasing architecture
AssigneeSTMicroelectronics (Rousset) SAS
InventorsMathieu Lisart, Nicolas Borrel
Life of this patent
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Abstract
An integrated circuit including a plurality of first semiconductor strips of a first conductivity type and of second semiconductor strips of a second conductivity type arranged in alternated and contiguous fashion on a region of the second conductivity type, including for each of the first strips: a plurality of bias contacts; for each bias contact, a switch capable of applying a potential on the bias contact; two detection contacts arranged at the ends of the first strip; and a detection circuit having its activation causing the turning off of the switches and the comparison with a threshold of the resistance between the detection contacts.
Claims20
A method of operating an integrated circuit having a plurality of first semiconductor strips of a first conductivity type and a plurality of second semiconductor strips of a second conductivity type arranged in alternated and contiguous fashion on a region of the second conductivity type, the method comprising:
- applying a first voltage to the plurality of first semiconductor strips;
- receiving a test signal;
- successively, for a respective first semiconductor strip of the plurality of first semiconductor strips, removing the first voltage applied to the respective first semiconductor strip;
- determining an electric resistance along the respective first semiconductor strip;
- determining whether the electric resistance is greater than a threshold resistance;
- and
- activating an alert signal in response to the electric resistance of any one of the plurality of first semiconductor strips being greater than the threshold resistance.
A method of operating an integrated circuit having a plurality of first semiconductor strips of a first conductivity type and a plurality of second semiconductor strips of a second conductivity type interdigitated with the plurality of first semiconductor strips, the method comprising detecting:
- receiving a test signal;
- disconnecting a bias contact of a first semiconductor strip of the plurality of first semiconductor strips from a bias voltage in response to a reception of the test signal;
- comparing, by a comparator, a first potential at a first detection contact of the first semiconductor strip to a threshold voltage, the first detection contact being arranged at a first end of the first semiconductor strip, the first potential being proportional to an electrical resistance of the first semiconductor strip between the first detection contact and a second detection contact arranged at a second end of the first semiconductor strip;
- and
- activating an alert signal in response to the first potential at the first detection contact being greater than the threshold voltage.
An integrated circuit, comprising:
- a plurality of first semiconductor strips of a first conductivity type;
- and
- a plurality of second semiconductor strips of a second conductivity type interdigitated with the plurality of first semiconductor strips, each of the first semiconductor strips comprising:
- a plurality of bias contacts;
- a plurality of switches, wherein each switch is associated with a respective bias contact, each switch capable of applying a bias potential on the respective bias contact;
- a first detection contact arranged at a first end of the first semiconductor strip;
- a second detection contact arranged at a second end of the first semiconductor strip, the second detection contact being controllably coupled to a reference voltage;
- an inverter configured to receive a test signal and control the plurality of switches based on the test signal;
- and
- a comparator having a first terminal coupled to the first detection contact and a second terminal configured to receive a threshold voltage, the comparator being configured to generate an alert signal in response to a first potential at the first detection contact being greater than the threshold voltage.
Dependencies are inferred from the claim text.