Device for detecting a laser attack in an integrated circuit chip

摘要

A device for detecting a laser attack made on an integrated circuit chip comprises a bipolar transistor of a first type formed in a semiconductor substrate, that bipolar transistor comprising a parasitic bipolar transistor of a second type. A buried region, forming the base of the parasitic bipolar transistor, operates as a detector of the variations in current flowing caused by impingement of laser light on the substrate.

主权项

1. A circuit, comprising:
a substrate of a first conductivity type; a buried region of a second conductivity type; an encircling region of the second conductivity type extending from a top surface of the substrate to contact the buried region; a well region of the first conductivity type surrounded by said encircling region and said buried region; a surface region of the second conductivity type formed in said well region; wherein the surface region, well region and buried region form a vertical bipolar transistor of a first type; wherein the vertical bipolar transistor includes a parasitic bipolar transistor of a second type; wherein a base terminal of said parasitic bipolar transistor is provided by said buried region; and wherein said buried region detects laser beam impingement on said substrate.