  Amorphous vanadium dioxide (VO$_{2}$) films deposited by atomic layer
deposition (ALD) were crystallized with an ex situ anneal at 660-670 ${\deg}$C
for 1-2 hours under a low oxygen pressure (10$^{-4}$ to 10$^{-5}$ Torr). Under
these conditions the crystalline VO$_{2}$ phase was maintained, while formation
of the V$_{2}$O$_{5}$ phase was suppressed. Electrical transition from the
insulator to the metallic phase was observed in the 37-60 ${\deg}$C range, with
a R$_{ON}$/R$_{OFF}$ ratio of up to about 750 and critical transition
temperature of 7-10 ${\deg}$C. Electric field applied across two-terminal
device structures induced a reversible phase change, with a room temperature
transition field of about 25 kV/cm in the VO$_{2}$ sample processed with the 2
hr long anneal. Both the width and slope of the field induced MIT hysteresis
were dependent upon the VO$_{2}$ crystalline quality.
