In-wafer Stress-dependent Leakage Current in Ferroelectric Scandium-doped Aluminum Nitride

Recently, the discovery of ferroelectricity in scandium-doped aluminum nitride (Al
1-x
Sc
x
N) makes it a promising candidate to be used for next-generation ferroelectric memory applications. However, the large operating voltage hinders its practical use owing to its relatively large coercive field (E
c
), which can be potentially reduced by strain engineering. Nevertheless, the relationship between stress and leakage current has not been investigated yet. In this work, we study the correlation between in-plane stress of AlScN film and leakage current of the ferroelectric Al
0.7
Sc
0.3
N-based capacitors. We observe that the leakage current relies closely on the film stress, in which less compressive stress will lead to smaller leakage current, providing the guidance for optimizing the film quality.