  A new mechanism for memristive switching in 2D materials is through
electric-field controllable electronic/structural phase transitions, but these
devices have not outperformed status quo 2D memristors. Here, we report a
high-performance bipolar phase change memristor from strain engineered
multilayer 1T'-MoTe$_{2}$ that now surpasses the performance metrics (on/off
ratio, switching voltage, switching speed) of all 2D memristive devices,
achieved without forming steps. Using process-induced strain engineering, we
directly pattern stressed metallic contacts to induce a semimetallic to
semiconducting phase transition in MoTe2 forming a self-aligned vertical
transport memristor with semiconducting MoTe$_{2}$ as the active region. These
devices utilize strain to bring them closer to the phase transition boundary
and achieve ultra-low ~90 mV switching voltage, ultra-high ~10$^8$ on/off
ratio, 5 ns switching, and retention of over 10$^5$ s. Engineered tunability of
the device switching voltage and on/off ratio is also achieved by varying the
single process parameter of contact metal film force (film stress $\times$ film
thickness).
