  Scaling of two dimensional six-contact phase change devices that can perform
toggle logic operations is analyzed through 2D electrothermal simulations with
dynamic materials modeling, integrated with CMOS access circuitry. Toggle
configurations are achieved through a combination of isolation of some contacts
from others using amorphous regions and coupling between different regions via
thermal crosstalk. Use of thermal crosstalk as a coupling mechanism in a
multi-contact device in the memory layer allows implementation of analog
routing and digital logic operations at a significantly lower transistor count,
with the added benefit of non-volatility. Simulation results show approximately
linear improvement in peak current and voltage requirements with thickness
scaling.
