Nxp B.v.

U.S. Philips Corporation

Johannes A J Van Geloven

Robertus A M Wolters

Pim Theo Tuyls

Nynke Verhaegh

Nynke Verhaech

Cornelis G L M Van Der Sanden

The invention relates to a tamper-resistant semiconductor device comprising a substrate () comprising an electronic circuit arranged on a first side thereof. An electrically-conductive protection layer () is arranged on a second side of the substrate () opposite to the first side. At least three through-substrate electrically-conductive connections () extend from the first side of the substrate () into the substrate () and in electrical contact with the electrically-conductive protection layer () on the second side of the substrate (). A security circuit is arranged on the first side connected to the through-substrate electrically-conductive connections () and is arranged for measuring at least two resistance values (R, R, R, R, R, R) of the electrically-conductive protection layer () through the through-substrate electrically-conductive connections (). The security circuit is further arranged for comparing the measured resistance values (R, R, R, R, R, R) with reference resistance values.

Tamper-resistant semiconductor device and methods of manufacturing thereof

An integrated circuit has an inhomogeneous protective layer or coating over a circuit to be protected, and a sensing circuit () arranged to sense a first impedance of a part of the protective coating compared to a reference impedance (CO) located on the integrated circuit. The sensing circuit is able to measure a change in the first impedance, e.g. caused by tampering. The sensing circuit has an amplifier (OTA) having a feedback loop, such that the impedance being sensed is in the feedback loop. The sensing circuit can be incorporated in an oscillator circuit (OTA, Comp) so that the frequency depends on the impedance. Where the impedance is a capacitance, sensing electrodes adjacent to the protective layer or coating, form the capacitance. The electrodes can be arranged as selectable interdigitated comb structures, so that the protective layer or coating extends in between the teeth of the comb structures.

Sensing circuit for devices with protective coating

An integrated circuit has a matrix of memory cells with a capacitive element and an access transistor. A plate conductor is connected to terminals of the capacitive element of all the memory cells. A voltage boost circuit boosts a voltage of the plate conductor to a voltage level outside a power supply range of the integrated circuit. A switching element is connected between the plate conductor and a control electrode of the access transistor. Thus the access transistor is controlled with the voltage of the plate conductor. Preferably, the voltage of the plate conductor is boosted below Vss and at a level regulated relative to Vdd.

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Eindhoven, Netherlands

Johannes A J Van Geloven