  This paper reports the fatigue and retention behavior for Al1-xBxN thin
films, a member of the novel family of wurtzite ferroelectrics, with an
emphasis on the role of capacitor architecture. By modifying the capacitor
architecture, and thus thermal and electrical boundary conditions, we create
insight regarding the relative importance of intrinsic and extrinsic
contributors to the degradation tendencies. Our experiments suggest that
bipolar cycling of metal (Pt/W)/Al0.93B0.07N/W/Al2O3 film stacks first induced
wake-up, then a region of constant switchable polarization. On additional
cycling, the film leakage current increased, and then films underwent
dielectric breakdown. For unpatterned first generation Al0.93B0.07N films with
100 nm thick Pt top electrodes survive ~104 bipolar cycles, whereas films with
1000 nm W top electrodes survive ~10^5 cycles before thermal dielectric
breakdown. Sentaurus modeling was used to design an SU8 field plate which
improved the performance to ~10^6 fatigue cycles. It was found that the thermal
failures during fatigue were not due to surface flashover events but were
associated with hard breakdown events in the dielectric. The films showed
excellent retention of the stored polarization state. As expected, data
retention was slightly inferior in the opposite state (OS) measurements.
However, it is noted that even after 3.6x10^6 sec (1000 hr). at 200{\deg}C, the
OS signal margin still exceeded 200 uC/cm2. The predicted OS retention is 82%
after 10 years baking at 200oC.
