Leakage Study of Ferroelectric AlScN Capacitors Prepared on Different Bottom Electrodes

The leakage-related issues are important obstacles for advancing the ferroelectric AlScN-based electronics. Moreover, the leakage characteristics of ferroelectric AlScN films varies with different bottom electrode materials. This work explained the leakage characteristics of AlScN films prepared on different bottom electrodes (single crystal Si, Pt metal electrode) using the Poole-Frenkel emission model. Although the Pt-based AlScN capacitor realized larger remnant polarization than its Si-based counterpart, the Pt sample exhibits smaller trap energy level, leading to larger leakage current and smaller breakdown voltage. Additionally, the increased remnant polarization values of Si-based AlScN capacitor after the endurance test is explained by the decreased trap energy level and thus the increased leakage current.