Integration of Single Oriented Oxide Superlattices on Silicon Using Various Template Techniques

Abstract

To benefit from the diverse functionalities of perovskite oxides in silicon-based complementary metal oxide semiconductor (CMOS) technology, integrating oxides into a silicon platform has become one of the major tasks for oxide research. Using the deposition of LaMnO 3 /SrTiO 3 (STO) superlattices (SLs) as a case study, we demonstrate that (001) single oriented oxide SLs can be integrated on Si using various template techniques, including a single-layer buffer of STO prepared by molecular beam epitaxy (MBE) and pulsed laser deposition, a multilayer buffer of Y-stabilized zirconia/CeO 2 /LaNiO 3 /STO, and STO-coated two-dimensional nanosheets of Ca 2 Nb 3 O 10 (CNO) and reduced graphene oxide. The textured SL grown on STO-coated CNO nanosheets shows the highest crystallinity, owing to the small lattice mismatch between CNO and STO as well as less clamping from a Si substrate. The epitaxial SL grown on STO buffer prepared by MBE suffers the largest thermal strain, giving rise to a strongly suppressed saturation magnetization but an enhanced coercive field, as compared to the reference SL grown on an STO single crystal. These optional template techniques used for integrating oxides on Si are of significance to fulfill practical applications of oxide films in different fields.

LaAlO3/SrTiO3 Heterointerface: 20 Years and Beyond

“…[163c,179] This has served as a basis by Chen et al to deploy various techniques including MBE, pulsed laser deposition (PLD), and the introduction of multiple-layer buffer to integrate LaMnO 3 /STO(001) into Si-based systems. [180] By at-tempting different integration techniques, the system comprising STO/Ca 2 Nb 3 O 10 is shown to possess the highest sample crystallinity due to the small lattice mismatch between the layers while the MBE-grown Si-integrated system produces a system with significantly suppressed saturation magnetization due to the presence of a large thermal strain. Even though it is still at the state of infancy, the successful integrated perovskite oxide/Si superlattice structures are ideal platforms particularly with their compatibility with existing Si-based wafer processing technology for the fabrication of highly-compact neuromorphic components and other electronic devices.…”

Tiling the Silicon for Added Functionality: PLD Growth of Highly Crystalline STO and PZT on Graphene Oxide-Buffered Silicon Surface

“…However, the obtained STO layer was actually polycrystalline in spite of the crystallinity improvement compared to the film obtained without the graphene interlayer . For the purpose of integrating functional oxides with a silicon platform, we have recently compared different templates for the growth of STO pseudo-substrate on Si, a reduced graphene oxide (rGO) among others . The present study provides more details on the STO growth mechanism and the role of rGO in this process.…”

“…29 For the purpose of integrating functional oxides with a silicon platform, we have recently compared different templates for the growth of STO pseudo-substrate on Si, a reduced graphene oxide (rGO) among others. 30 The present study provides more details on the STO growth mechanism and the role of rGO in this process. Furthermore, the potential of the as-prepared STO layer to be used as a pseudo-substrate was evaluated by overgrowing a PbZr 1−x Ti x O 3 (PZT) layer.…”

Robust SrTiO3 Passivation of Silicon Photocathode by Reduced Graphene Oxide for Solar Water Splitting

“…In the present study, we used pulsed laser deposition (PLD) to prepare an STO epitaxial layer on a Si photocathode, where in between the film and the substrate a buffer layer of reduced graphene oxide (rGO) was introduced. In our previous work we demonstrated the necessity of rGO as an epitaxy template guiding the growth of STO along the preferential orientation. , To obtain the best quality of STO layer, an rGO-coated Si substrate with full coverage was adopted as the overgrown template . Moreover, it has been reported that the high electrical conductivity of rGO can accelerate the charge transfer between the semiconductor and the electrolyte and significantly enhance the PEC efficiency. , Herein, the crystal and microstructural properties of the grown STO layer were investigated and discussed using X-ray diffractometry (XRD), in situ reflection high-energy electron diffraction (RHEED), and atomic force microscopy (AFM), in comparison to the polycrystalline film where STO was directly deposited on Si without rGO.…”