Impact of 12-nm FinFET Technology Variations on TID Effects: A Comparative Study of GF 12LP and 12LP+ at the Transistor Level

This paper presents a comparative analysis of total ionizing dose (TID) response in GlobalFoundries' 12LP and 12LP+ 12nm bulk FinFET technologies using 10keV X-rays. Our findings show that 12LP+ n-type transistors demonstrate higher sensitivity to TID degradation of off-state leakage drain current compared to 12LP. Data indicate that for both 12LP and 12LP+, transistors with higher threshold voltages exhibit lower off-state drain-source leakage post-irradiation compared to transistors with lower threshold voltages. Data consistently show that transistors with fewer fins per transistor show superior TID tolerance, in both 12LP and 12LP+ technologies. Lower threshold voltage transistors in both technologies display similar pre-irradiation leakage currents. On the other hand, higher threshold voltage transistors in 12LP+ show lower pre-irradiation leakage currents than those in 12LP, highlighting that the front-end-of-line of 12LP+ technology has been modified compared to 12LP. P-type devices in 12LP+ presented negligible degradation. Larger TID sensitivity in 12LP+ might be attributed to the implementation of dual metal gate work functions, reduced halo doping, deeper Source/Drain doping profiles, and/or 12LP+ having narrower fins compared to 12LP.