Theoretical Model of Transient Current in CMOS Inverter Under IR Laser Pulse Responsible of Bitflip in FDSOI Technology

A theoretical model of the induced transient photocurrent in MOS transistor under laser illumination is proposed to predict an estimation of the incident power surface density of the laser required to create a bitflip. This model based on the physical effect of the laser interaction with the semiconductor material (silicon) takes into account the laser characteristics, the physical properties of the silicon, and the geometrical and technological parameters. The results highlight the volume effects, with a higher photocurrent level due to a higher total electron/hole pair generation for a thicker active layer, making the structures more sensitive to fault injection by pulsed IR laser, particularly for conventional bulk CMOS technologies and for FDSOI technologies based on FINFETs. This theoretical model combined with electrical model based on phototransistor is a good predictive tool in complements with TCAD simulations for studies of vulnerability analysis in advanced FDSOI silicon technologies and enables parametric analysis of physical phenomena related to the technology, in order to anticipate experimental studies of the vulnerability by laser fault injection of complex electronic systems.