For a short time, it looked like the worlds electronics would be safe (well, safer) from radiation. With the switch from planar transistors to FinFETs, ICs suddenly became naturally resistant (literally) to having their bits flipped by a neutron splashing into them and blasting lose a small cloud of charge. But two things are now making them vulnerable again: One is the move to operating at voltages so low, that it’s easier for a pulse of radiation-induced charge to flip a transistor on or off. The other is how the unprecedented density of those transistors is giving radiation more targets than ever.
Engineers at the University of Minnesota are nearing a solution that could help bring down the rate of so-called logic soft errors—signals temporarily flipped by a radiation strike. It’s a circuit called a back-sampling chain that has, for the first time, allowed them to reconstruct the strike pulse—called a single event transient—resulting from the radiation strike. In research to be presented in June at the IEEE VLSI Symposia in Kyoto, Kim’s team shows that the back-sampling chain (BSC) circuit—a kind of cross-connected chain of inverters—can detect orders of magnitude higher number of strikes compared to previous approaches.