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Integration of Biaxially Aligned Conducting Oxides with Silicon using Ion-Beam Assisted Deposited MgO Templates Luke A. Emmert, Bae-Ho Park, James R. Groves, Raymond F. DePaula, Q.X. Jia, and Paul N. Arendt Superconductivity Technology Center, Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87544 ABSTRACT Two conducting oxides, La0.5Sr0.5CoO3(LSCO) and SrRuO3, were deposited by pulsed laser ablation onto silicon substrates coated with biaxially textured MgO on an amorphous silicon nitride isolation layer. Comparison is made between templates using just 10 nm of ion-beam assisted deposited (IBAD) MgO and substrates with an additional 100 nm of homoepitaxial MgO. Both of these conducting oxide layers exhibited in-plane and out-of-plane texture, on the order of that obtained by the underlying MgO. The SrRuO3 was c-axis oriented on both substrates, but exhibited a slightly sharper out-ofplane texture when the homoepitaxial MgO layer was included. On the other hand, the LSCO showed only (100) orientation when deposited directly on the IBAD-MgO templates, whereas a significant (110) peak was observed for films on the homoepitaxial MgO. A simple calculation of the distribution of grain boundary angles, assuming a normal distribution of grains, is also presented. INTRODUCTION Integration of oxides with silicon electronics has been a stumbling block for promising applications. One can deposit structures on oxidized silicon, but the resultant polycrystalline films dilute the properties that often depend on crystalline anisotropy. Moreover, the high-angle grain boundaries can adversely affect the properties by changing the defect chemistry. Alternatively, one can grow heteroepitaxial oxides directly on silicon, but thermochemistry limits one’s choice of materials[1]. This method is best left to gate oxides where the silicon-oxide interface is crucial for the application. Ramesh et al.[2] demonstrated that one can obtain fiber textured oxide films without using the crystallinity of the substrate by first depositing Bi4Ti3O12 which has a tendency for uniaxial growth. Ion-beam assisted deposition is a useful way for controlling the texture of thin films during growth. Recently, Wang et al.[3] have shown that biaxial texture can be achieved by depositing MgO with ion-beam assistance(IBAD-MgO). We have applied this technique to superconducting tapes, where the elimination of high-angle F7.2.1

grain boundaries improves the critical current density[4]. In this paper we demonstrate the growth of other conducting perovskites with biaxial texture in preparation for later studies on the effect of reducing the density of high-angle grain boundaries on electrical properties of other perovskites. EXPERIMENTAL DETAILS The IBAD-MgO films were deposited on as-received silicon wafers after coating with 20 nm of amorphous silicon nitride evaporated by electron-beam. MgO was evaporated by electron-beam evaporation while simultaneously exposing the substrate to a flux of argon ions accelerated to 750 eV.