Reliable 5 ns writing of spin-transfer torque MRAM

We report reliable 5 ns switching of spin-transfer torque magnetoresistive random-access memory devices of nominal size 43 nm and a resistance area product of 11 Ω·µm2. We measured 256 devices with a 100% write-error-rate (WER) yield at a WER floor of $10^{-6}$ and a steep WER slope as a function of voltage. A single device had a WER less than $10^{-10}$ for 5 ns write pulses. We show promising 3 ns switching performance, with a 94% WER yield at a $10^{-6}$ WER floor, for 64 devices of nominal size 50 nm.