Patent ID: 11942440
Assignee: STMICROELECTRONICS (ROUSSET) SAS
Field: Computer technology (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 0:
1. An integrated circuit, comprising:
a semiconductor substrate having a rear face and a front face opposite to said rear face;
a first semiconductor well in the semiconductor substrate;
a second semiconductor well in the semiconductor substrate, the second semiconductor well insulated from the first semiconductor well and from a rest of the semiconductor substrate;
wherein the second semiconductor well includes a PN junction; and
a detecting device configured to operate to detect a Differential Fault Analysis (DFA) attack initiated by application of a laser radiation to the semiconductor substrate through detection of a photocurrent flowing in the second semiconductor well, wherein said photocurrent is generate by said PN junction in response to the laser radiation;
wherein the detecting device comprises:
a first isolation trench extending into the second semiconductor well between two locations on a periphery of the second semiconductor well, said first isolation trench having a depth from the front face that is separated by a distance from a bottom of the second semiconductor well;
two contact areas respectively situated on opposite sides of the first trench; and
a detection circuit operating to detect the presence of said photocurrent flowing at one or more of the two contact areas.