Device for detecting the thinning down of the substrate of an integrated circuit chip
AssigneeSTMicroelectronics (Rousset) SAS
InventorsPascal Fornara, Christian Rivero
Life of this patent
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Abstract
A device for detecting the thinning down of the substrate of an integrated circuit chip, including, in the active area of the substrate, bar-shaped diffused resistors connected as a Wheatstone bridge, wherein: first opposite resistors of the bridge are oriented along a first direction; the second opposite resistors of the bridge are oriented along a second direction; and the first and second directions are such that a thinning down of the substrate causes a variation of the imbalance value of the bridge.
Claims22
A device for detecting a thinning down of a substrate of an integrated circuit chip, comprising, in an active area of the substrate, bar-shaped diffused resistors connected as a Wheatstone bridge, wherein:
- first opposite resistors of the bridge are oriented along a first direction;
- second opposite resistors of the bridge are oriented along a second direction;
- and
- said first and second directions are such that the thinning down of the substrate causes a variation of an imbalance value of the bridge, wherein the second opposite resistors vary in response to thinning of the substrate and the first opposite resistors are substantially unchanged in response to the thinning of the substrate and wherein an imbalance in the bridge is indicative of the thinning of the substrate.
A device for detecting a thinning down of a substrate of an integrated circuit chip, comprising, in an active area of the substrate, bar-shaped diffused resistors connected as a Wheatstone bridge, wherein:
- first opposite resistors of the bridge are oriented along a first direction;
- second opposite resistors of the bridge are oriented along a second direction;
- and
- said first and second directions are such that the thinning down of the substrate causes a variation of an imbalance value of the bridge, wherein main surfaces of the substrate are in plane [001] of a crystal structure of the substrate, and wherein:
- said diffused resistors are formed in a P-type doped substrate region;
- said first and second directions respectively correspond to directions (100) and (110) of the crystal structure of the substrate;
- and
- said second opposite resistors are each surrounded with an insulating region covered with a polysilicon layer, the entire resistor being covered with a protection nitride layer.
A semiconductor device comprising:
- a substrate;
- and
- a bridge circuit formed in the substrate, the bridge circuit comprising a first resistor connected between a voltage and a first node, a second resistor connected between the first node and ground, a third resistor connected between the voltage and a second node, and a fourth resistor connected between the second node and ground, wherein the first and fourth resistors vary in response to thinning of the substrate and the second and third resistors are substantially unchanged in response to the thinning of the substrate and wherein an imbalance in the bridge is indicative of thinning of the substrate.
Dependencies are inferred from the claim text.