US 11,942,440 B2
Method for detecting a differential fault analysis attack and a thinning of the substrate in an integrated circuit, and associated integrated circuit
Alexandre Sarafianos, Pourrieres (FR); and Abderrezak Marzaki, Aix en Provence (FR)
Assigned to STMicroelectronics (Rousset) SAS, Rousset (FR)
Filed by STMicroelectronics (Rousset) SAS, Rousset (FR)
Filed on Nov. 6, 2020, as Appl. No. 17/091,466.
Application 17/091,466 is a continuation of application No. 16/154,456, filed on Oct. 8, 2018, granted, now 10,892,234.
Claims priority of application No. 1759519 (FR), filed on Oct. 11, 2017.
Prior Publication US 2021/0057358 A1, Feb. 25, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 23/00 (2006.01); G06F 21/55 (2013.01); G06F 21/78 (2013.01); G06F 21/87 (2013.01); H01L 29/06 (2006.01); H04L 9/00 (2022.01)
CPC H01L 23/576 (2013.01) [G06F 21/556 (2013.01); G06F 21/78 (2013.01); G06F 21/87 (2013.01); H01L 29/0646 (2013.01); H01L 29/0649 (2013.01); H04L 9/004 (2013.01); H04L 2209/12 (2013.01)] 18 Claims
OG exemplary drawing
 
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.