Heteroepitaxial growth of lead magnesium niobate-lead titanate thin films by pulsed laser deposition method

Abstract

In the present research we have used pulsed laser deposition (PLD) method to prepare super high-k (1-x)[Pb(Mg1/3Nb2/3)O3]-x[PbTiO3] (PMN1-x-PTx) dielectric thin films for future high-density dynamic random access memory (DRAM) applications. PMN1-x-PTx, films with x = 0.1 and 0.35 have been grown on various substrates with La0.7Sr0.3MnO3 (LSMO) and BaPbO3 (BPO) conducting oxides as well as Pt bottom electrodes. Conditions for heteroepitaxial growth of PMN-PT films have been identified. Structural and electrical properties of all these films have been carefully evaluated and compared. Integration of PMN-PT super high-k dielectric films with Si has been attempted via Pt and TiN buffer layers. Good structural quality PMN-PT/Pt/Si, PMN-PT/LSMO/Pt/Si and PMN-PT/BPO/Pt/Si heterostructures have been obtained. In addition, heteroepitaxial (001)PMN-PT (001)LSMO (001)MgO (001)TiN (001)Si has been demonstrated. Our results also reveal that the use of lead based oxide electrode (BPO) has reduced the dielectric leakage current. A maximum room temperature dielectric constant of 1750 at 10 kHz and a minimum leakage current of 6.78x10-9 A/cm2 at 1V have been recorded.