NUMERICAL MODELING OF MECHANISMS INVOLVED IN LATCHUP TRIGGERING BY A LASER-BEAM

The use of a laser beam is a will-known technique to trigger latchup p arasitic structures in ICs. Numerical analyses of this phenomenon are brought into play to study its sensitivity when a continuous wave lase r as well as pulsed lasers are used. The impact location is also studi ed to demonstrate that different mechanisms are involved in the trigge ring phase of latchup. The structure is also more sensitive to the blu e light when it is directed over the well-substrate junction while it is more sensitive to infrared light elsewhere. When using a CW laser, the curves giving the power supply current versus the photo-induced cu rrent provide direct information on the parameters of the parasitic st ructure.