Ag/HfO2 based threshold switch with extreme non-linearity for unipolar cross-point memory and steep-slope phase-FETs

We demonstrate a novel Ag/HfO
₂
based threshold switch (TS) with a selectivity~10
⁷
, a high ON-state current (Ion) of 100μA, and ~10pA leakage current. The thresholding characteristics of the TS result from electrically triggered spontaneous formation and rupture of an Ag filament which acts an interstitial dopant in the HfO
₂
insulating matrix. Further, we harness the extreme non-linearity of the TS in (1) Selectors for Phase Change Memory (PCM) based cross-point memory. We show through array level simulations of a 1024kb memory, a read margin of 28% and write margin of 32% for a leakage power of <;25μW (V/3 scheme); (2) A steep-slope sub-kT/q Phase-FET, experimentally demonstrating a switching-slope (SS) of 3mV/decade (over 5 orders of I
_DS
), and >10x I
_ON
improvement over the conventional FET (at iso-I
_OFF
) at T=90C (50x at T=25C); making this a promising TS for both emerging memory, and steep-slope transistor applications.