Further Analysis of Laser-induced IR-drop

Abstract

Studies on laser induced IR-drop are recent and still not much covered. Since laser-induced IR-drop can amplify the well-known effects of induced photoelectric currents in ICs, this work aims to present important characteristics of such effect. Understanding the characteristics and effects of laser induced IR-drop in ICs allows the elaboration of more accurate simulation models, and consequently helps in the design of countermeasures that mitigate the effects of laser illumination. Simulations and experiments were performed in order to understand the relationship of the laser pulse width and the decoupling capacitance of the power supply network with the induced IR-drop. The results showed that the maximum variation of the supply voltage depends on the laser pulse duration, and on other circuit characteristics, such as RLC parameters of the supply network. It was possible to observe by simulations and experiments that, for the proposed circuit, the maximum variation of the supply voltage occurred for a laser pulse greater than or equal to 1 μs. Regarding the decoupling capacitance variation, the results showed that for a decoupling capacitor up to 100 pF, the IR-drop becomes even more relevant with a variation up to 97% of VDD.