Dependence of polarization on temperature coefficient resistance of (Ba, Sr)TiO3 thin films post-treated by RTA

The temperature coefficient of resistance (TCR) characteristics of Pt/(Ba 0 . 8 Sr 0 . 2 )TiO 3 (BST)/Pt thin-film resistors are studied for the BST films with rapid thermal annealing (RTA) treatments. The polarizations induced by bias voltages greatly influence the TCR characteristics. The RTA-treated BST thin film exhibits negative TCR (NTCR) behavior at a negative voltage, but, intriguingly, positive TCR (PTCR) behavior at a positive voltage. According to the leakage current analysis, Schottky emission dominates the negatively biased current at the upper interface, but Heywang barrier scattering confines the positive biased current.