Size effect on the ultrathin ferroelectric film directly grown on silicon for electronic devices

Abstract

We demonstrate that the size effects impact on the electrical properties of the ultrathin Bi_3.15Nd_0.85Ti₃O₁₂ (BNT) film grown directly on silicon. The remnant polarization is observed for the 2 nm thick BNT film by direct quantitative P–V measurements and the corresponding obvious contrast images are confirmed by scanning probe microscopy. We address the physical mechanism of the ferroelectric behavior of the ultrathin films deposited on Si substrates which is different from those grown on the metal and oxide substrates. Moreover, the results also reveal low leakage current, good fatigue and retention characteristics. This opens the way for the ultrathin ferroelectric films directly grown on Si substrates for Si-based integrated microelectronics while they still retain excellent electrical properties. In addition, we also discuss the possible microcosmic mechanism of the performance of the ultrathin film integrated with current Si technology in electronic miniaturization devices.