  The interfacial Dzyaloshinskii-Moriya interaction (DMI) has been shown to
stabilize homochiral N\'eel-type domain walls in thin films with perpendicular
magnetic anisotropy and as a result permit them to be propagated by a spin Hall
torque. In this study, we demonstrate that in Ta/Co$_{20}$Fe$_{60}$B$_{20}$/MgO
the DMI may be influenced by annealing. We find that the DMI peaks at
$D=0.057\pm0.003$ mJ/m$^{2}$ at an annealing temperature of 230 $^{\circ}$C.
DMI fields were measured using a purely field-driven creep regime domain
expansion technique. The DMI field and the anisotropy field follow a similar
trend as a function of annealing temperature. We infer that the behavior of the
DMI and the anisotropy are related to interfacial crystal ordering and B
expulsion out of the CoFeB layer as the annealing temperature is increased.
