Epitaxial La0.7Sr0.3MnO3 thin films on silicon with excellent magnetic and electric properties by combining physical and chemical methods

José Manuel Vila-Fungueiriño,Jaume Gázquez,César Magén,Guillaume Saint-Girons,Romain Bachelet,Adrián Carretero-Genevrier

doi:10.1080/14686996.2018.1520590

Abstract

ABSTRACTHalf-metallic ferromagnetic La0.7Sr0.3MnO3 (LSMO) represents an appealing candidate to be integrated on silicon substrates for technological devices such as sensors, data storage media, IR detectors, and so on. Here, we report high-quality epitaxial LSMO thin films obtained by an original combination of chemical solution deposition (CSD) and molecular beam epitaxy (MBE). A detailed study of the thermal, chemical, and physical compatibility between SrTiO3 (STO)/Si buffer layers and LSMO films, grown by MBE and CSD, respectively, enables a perfect integration of both materials. Importantly, we show a precise control of the coercive field of LSMO films by tuning the mosaicity of the STO/Si buffer layer. These results demonstrate the enormous potential of combining physical and chemical processes for the development of low-cost functional oxide-based devices compatible with the complementary metal oxide semiconductor technology.

Highlights

Transition metal oxides are robust materials that can exhibit outstanding electric, magnetic, optical, mechanical, and thermic properties [1]
The existence of fringes in the X-ray reflectivity (XRR) curves of the LSMO layers (Figure S2) implies very low interface and surface roughness values, similar to the STO buffer layer grown by molecular beam epitaxy (MBE)
The thermal and chemical stability exhibited by STO layers grown on silicon substrates by MBE allowed chemical deposition of high-quality epitaxial LSMO ultrathin films using polymerassisted deposition (PAD) process at 950 °C in air atmosphere within 2 h on STO/Si buffer layers preannealed at 900 °C

Summary

Introduction

Transition metal oxides are robust materials that can exhibit outstanding electric, magnetic, optical, mechanical, and thermic properties [1]. Epitaxial functional oxide thin films on silicon are exclusively grown by physical methods in ultra-high vacuum conditions, which require a perfect control of the partial oxygen pressure during the synthesis, to prevent the formation of an amorphous SiO2 layer or undesirable crystalline silicates.

Results

Conclusion