Response Variability in Commercial MOSFET SEE Qualification

Single-event effects (SEE) evaluation of five different part types of next generation, commercial trench MOSFETs indicates large part-to-part variation in determining a safe operating area (SOA) for drain-source voltage ( $\text {V}_{\mathrm { {DS}}}$ ) following a test campaign that exposed >50 samples per part type to heavy ions. These results suggest a determination of a SOA using small sample sizes may fail to capture the full extent of the part-to-part variability. An example method is discussed for establishing a Safe Operating Area using a one-sided statistical tolerance limit based on the number of test samples. Burn-in is shown to be a critical factor in reducing part-to-part variation in part response. Implications for radiation qualification requirements are also explored.