Timing Vulnerability Factors of Ultra Deep-sub-micron CMOS

Soft errors are a significant reliability issue for Ultra Deep-Sub-Micron (UDSM) CMOS circuits. Therefore, an accurate assessment of the Soft Error Rate (SER) is crucial. In this paper, we argue that the conventional definitions for the Window of Vulnerability (WOV) under-estimate the risk. We propose a new method for determining the timing factors and WOV for the sequential elements from the susceptibility perspective rather than the conventional performance perspective. We also discuss that the process variation does not have any special impact on the WOV. Our methodology leads to a more realistic definition of the WOV for SER computation.