Thermal response of integrated circuit input devices to an electrostatic energy pulse

The thermal response to an electro static discharge (ESD) pulse in silicon is presented and discussed using the three-dimensional heat equation and a set of boundary conditions that physically simulate the behavior of input protection mechanisms commonly used in integrated circuits. Waveforms that vary exponentially and linearly in time are quantitatively analyzed for a spatially localized hot spot and for an even distribution of heat along a circular periphery. The results confirm recent observations that deviation from the smooth and slow exponential waveform due to parasitic oscillations and coupling is a major cause of ESD related damage.