Enhanced memory window of Au/BaTiO3/SrTiO3/Si(001) MFIS structure with high c-axis orientation for non-volatile memory applications

Abstract

Metal-ferroelectric-insulator-semiconductor (MFIS) structures with BaTiO 3 (BTO) as a ferroelectric film and SrTiO 3 (STO) as an insulating buffer layer were fabricated on p-type Si(001) substrates using an ion beam sputter deposition technique. The effect of out-of-plane orientation on the electrical properties of the MFIS structures, including leakage current density and memory window behavior, were studied using the growth of the BTO ferroelectric film on Si substrate buffered by highly c-axis-oriented and randomoriented STO buffer layers. The experimental results show that the out-of-plane orientations of the BTO films were almost identical to those of the STO buffer layers. The MFIS structure with a high c-axis orientation exhibited a maximum clockwise capacitance-voltage memory window of 1.17 V with a low leakage current of 1.05 × 10 −7 A/cm 2 at an applied voltage of 4 V, which is a significant improvement compared to the MFIS structure with a random orientation. The difference in the electrical properties of the MFIS structures with both types of orientation is discussed in detail. The results obtained from this study indicate that

Integration of lead-free ferroelectric on HfO2/Si (100) for high performance non-volatile memory applications

“…S5 online]. The contrary results were obtained in some ferroelectric based NVM devices reported earlier where the memory window decreased after a certain voltage393039. The decrease of memory window was ascertained to be the charge injection and build of depolarization field at the ferroelectric/semiconductor interface.…”

Growth of highly (110)- and (111)-textured SrTiO3 thin films on Pt(111)/α-Al2O3(0001) substrates by ECR ion beam sputter deposition

“…The dielectric properties of STO thin films were found to be significantly different from the bulk and strongly dependent on crystallographic orientations [4][5][6]. Thus, the control of film orientation is a key point for improving dielectric properties and exploring new functionalities of films.…”

Enhanced Electro‐Optic Coefficients in Single‐Crystalline BaTiO3 Thin Films Enabled by Domain Alignment

“…Numerous reports have showcased the integration of BTO epitaxial films with silicon platforms using various techniques. [11][12][13][14][15][16][17] Nevertheless, these methods have revealed dramatic variations in the EO coefficients of the BTO films, depending on the quality and domain alignment of the films are critical factors. Moreover, the epitaxial growth of BTO films on silicon requires the use of SrTiO 3 (STO) as a buffer layer to overcome the lattice mismatch of ≈4%, which would induce compressive strain and subsequently affect the ferroelectric domain architecture in BTO.…”