Single crystalline BaTiO3 thin films synthesized using ion implantation induced layer transfer

Abstract

Layer transfer of BaTiO 3 thin films onto silicon-based substrates has been investigated. Hydrogen and helium ions were co-implanted to facilitate ion-implantation-induced layer transfer of films from BaTiO 3 single crystals. From thermodynamic equilibrium calculations, we suggest that the dominant species during cavity nucleation and growth are H 2 , H + , H 2 O, Ba 2+ and Ba-OH, and that the addition of hydrogen to the Ba-Ti-O system can effectively suppress volatile oxide formation during layer transfer and subsequent annealing. After ion implantation, BaTiO 3 layers contain microstructural defects and hydrogen precipitates in the lattice, but after layer transfer, the single crystal is found to be stoichiometric. Using direct wafer bonding and layer splitting, single crystal BaTiO 3 thin films were transferred onto amorphous Si 3 N 4 and Pt substrates. Micro-Raman spectroscopy indicated that the density of defects generated by ion implantation in BaTiO 3 can be significantly reduced during post-transfer annealing, returning the transferred layer to its single crystal state. Characterization using piezoresponse force microscopy shows that the layer transferred thin films are ferroelectric, with domain structures and piezoresponse characteristics similar to that of bulk crystals.

Optimization of magnetoelectricity in piezoelectric–magnetostrictive bilayers

“…However, single crystals are highly anisotropic and it is not clear how they should be oriented with respect to the layer normal for optimal ME coupling. Recent advances in wafer bonding and layer transfer enables the fabrication of high quality single-crystal ferroelectric films of potentially arbitrary orientations on diverse substrates [19]. Indeed, experiments by Yang et al [20] and Wang et al [21] show that single crystals are attractive and the effective ME coefficient of the laminate can depend sensitively on the crystallographic orientation of the material.…”

Competing failure mechanisms in thin films: Application to layer transfer

“…Recently, the layer transfer process has been proposed and shows promise as an alternative when the film/substrate pair is very different. 2,3 Layer transfer is accomplished by implanting hydrogen or helium ions into a bulk crystal of the film to be transferred and then bonding it to a substrate. Acting as damage precursors, these ions induce nucleation and growth of cavities when the specimen is heated at a sufficiently high temperature, transferring onto the substrate a single crystal thin film whose thickness corresponds to the depth of ion implantation.…”

Silver diffusion bonding and layer transfer of lithium niobate to silicon

“…The combination of these two methods enables thin-film single crystal layer transfer of a wide variety of semiconductors 3-5 and ferroelectrics. [6][7][8] By combining the flexibility of bottom-up processing with the near-ideal optical and electronic properties of single crystal films, these two techniques have become the standard method for producing silicon-on-insulator. 4,5 In addition, wafer bonding and layer transfer has enabled ultrahigh efficiency, multijunction solar cells to be fabricated by bonding lattice-mismatched semiconductors.…”