Electrical conduction transition and largely reduced leakage current in aluminum-doped barium strontium titanate thin films heteroepitaxially grown on Ir∕MgO∕Si(100)

Abstract

Ba 0.6 Sr 0.4 Ti 1 − x Al x O 3 (BSTA, x=0, 3 at. %, 6 at. %) thin films have been prepared on Ir∕MgO-buffered silicon substrates by pulsed-laser deposition. All-epitaxial growth of BSTA∕Ir∕MgO∕Si heterostructures has been evidenced by x-ray diffraction and reflection high-energy electron diffraction. A large reduction in the leakage current density of BSTA thin films was observed by aluminum doping. For 3 at. % Al-doped BSTA thin films, the dominant conduction mechanism shows space-charge-limited current behavior at a low electric field, where the trap-filled limit field is determined as ETFL=10KV∕cm, while at a high electric field the Poole–Frenkel emission is operative. In contrast, the conduction mechanism for 6 at. % Al-doped BSTA thin film is dominated by field-enhanced Schottky emission.

Preparation, microstructure and electrical properties of 0.7Pb(Mg1/3Nb2/3)O3–0.3PbTiO3 films on different epitaxial bottom electrodes buffered Si substrates

“…The detailed preparation processes about bottom electrode/MgO/TiN/ Si heterostructures have been reported elsewhere [18][19][20][21]. The prepared bottom electrodes exhibit atomic smooth surface and high electrical conductivity.…”

“…In this work, various epitaxial thin films (Pt, Ir and LSCO) grown on MgO/Si substrates [18][19][20][21] were selected as bottom electrodes for subsequent deposited PMNT films. Through careful optimization of growth conditions, completely (0 0 1)-oriented 0.7 Pb(Mg 1/3 Nb 2/3 )O 3 -0.3PbTiO 3 films have been successfully prepared on Irand LSCO-bottom electrodes buffered Si substrates.…”

Growth of La0.5Sr0.5CoO3 thin film on MgO-buffered Si substrate by pulsed laser deposition method: Evolution of crystalline orientation, morphology and growth mode with substrate temperature

“…More detailed results about the growth and characterization of MgO/TiN buffer layers can be found in Refs. [13,14]. Finally, for the growth of the LSCO thin films, the oxygen pressure in the chamber was further raised to 200 mTorr, substrate-target distance was kept at 50 mm, laser fluence was controlled at 3 J/cm 2 and substrate temperature was varied from 500 to 750 1C.…”

“…The selection of this buffer was inspired due to the following two reasons: (i) MgO can be grown epitaxially on Si substrates by inserting only 1 nm thick TiN [13,14] and (ii) the lattice constant of LSCO and MgO are 0.383 and 0.421 nm, respectively. Thus, a relative low lattice mismatch about 9% exists between them.…”

Leakage current suppression in solution-deposited barium titanate films on copper foils

“…The J-E relationships for the three electronic conduction mechanisms are listed in Table 2. Accordingly, the J-E curves of the SCLC, Schottky and Poole-Frenkel conduction (PFC) are characterized by the linear relationships of log(J)-log(E), ln(J)-E 1/2 , and ln(J/E)-E 1/2 respectively [18].…”