Study on the ferroelectric properties of high Sc doped AlN thin films

Wurtzite ferroelectric materials have attracted extensive research interest due to their large remnant polarization, excellent high-temperature stability and compatibility with semiconductor processes.The main challenges hindering the application of Sc-doping AlN (AlScN) ferroelectric thin films in non-volatile memory is the large coercive field (E_c) and high leakage current at high electric field.In this study, high scandium content Al_0.57Sc_0.43N ferroelectric thin films were deposited using magnetron sputtering on different electrodes (Mo, TiN, and Al).The results show that Al_0.57Sc_0.43N thin films deposited on bottom electrodes (Mo, TiN, and Al) exhibit preferred c-axis orientation and obtained significant ferroelectricity, with coercive fields of 2.6, 3.5, and 2.3 MV/cm, respectively.However, the microstructure and breakdown strength are affected obviously by the electrodes.The Al_0.57Sc_0.43N thin film deposited on TiN bottom electrodes obtained a higher P_r value of 155 μC/cm², and the leakage current is lower, making it a promising material for non-volatile ferroelectric memory applications.