Nitrogen Vacancies Cause Thermal Breakdown in Ferroelectric Al_1-xB_xN

Ferroelectrics have attracted attention as a material to create back-end-of-line and complimentary-metal-oxide-semiconductor compatible in-compute memory. Al_1-xB_xN has been identified as a candidate due to its large memory window, low volatility, and high temperature operation. However, Al_1-xB_xN devices fatigue and do not currently have sufficient endurance for adoption relating to an increased polarization and defect density. To identify the defect responsible for this limited endurance, a combination of electronic and optical spectroscopies characterized the Al_1-xB_xN through its lifetime. Using electrical measurements, photoluminescence, and Q-DLTS, we've identified the increase in non-switching polarization is directly related to the intensity of a transition between V_N and an oxygen complex. The increase in V_N concentration is attributed to the switching polarization in the material facilitating the creation of new defects through hot atom damage. Therefore, switching in Al_1-xB_xN leads to an increase in V_N which ultimately causes thermal breakdown in Al_1-xB_xN.