Efficient characterization of transient pulse shapes from radiation induced upsets

Abstract

Single Events Upsets (SEU) have long been a concern of the space and aviation fields. An SEU occurs when the logic state of a data-storage element in an integrated circuit changes because of the charge generated by a single ionizing particle. In the past, the minimum amount of deposited charge required from an event to cause an upset, was relatively large compared to present technologies. This kept the focus of the industry on heavy ions that had relatively high kinetic energy. As devices continue to scale down, the value for critical charge will also decrease. This will require attention to particles that could previously be ignored. Even terrestrial circuits will be exposed to particles that now have the ability to upset a cell. Current transients resulting from a single-event strike can be generated from 3D technology computer aided design (TCAD) device simulations to aid in determining an accurate SEU rate. These device level transient simulations can be time intensive, requiring significant overhead to calibrate a device response. This work describes a physics-based approach to estimating prompt current transient pulse shapes efficiently and accurately using a closed-form equation. This method of pulse shape calibration is accomplished without running time-consuming finite element transient simulations and only requires minimal device geometry information. Creating these pulses efficiently with this method enables designers to estimate transient responses quickly, allowing for seamless integration into higher level simulations.