Effect of Extrinsically Introduced Passive Interface Layer on the Performance of Ferroelectric Tunnel Junctions

We report the effect of the top electrode/functional layer interface on the performance of ferroelectric tunnel junctions. Ex situ and in situ fabrication process were used to fabricate the top Pt electrode. With the ex situ fabrication process, one passive layer at the top interface would be induced. Our experimental results show that the passive interface layer of the ex situ devices increases the coercive voltage of the functional BaTiO₃ layer and decreases the tunneling current magnitude. However, the ex situ tunneling devices possess more than 1000 times larger ON/OFF ratios than that of the in situ devices with the same size of top electrode