Single-crystal epitaxial thin films of the isotropic metallic oxides Sr1–xCaxRuO3 (0 ≤ x ≤ 1) were grown on miscut SrTiO3(100) substrates in situ by 90° off-axis sputtering. These thin films exhibit low isotropic resistivities, excellent chemical and thermal stability, good surface smoothness, and high crystalline quality. Furthermore, the lattice parameters and magnetic properties can be varied by simply changing the strontium/calcium ratio. These epitaxial thin films, and their multilayer structures with other oxide materials, can be used for the fabrication of superconducting, ferroelectric, magneto-optic, and electro-optic devices.

https://science.sciencemag.org/content/sci/258/5089/1766.full.pdf

Single-Crystal Epitaxial Thin Films of the Isotropic Metallic Oxides Sr1–xCaxRuO3 (0 ≤ x ≤ 1)

A memory cell array has a first and a second storage area. The first storage area has a memory elements selected by an address signal. The second storage area has a memory elements selected by a control signal. A control circuit has a fuse element. When the fuse element has been blown, the control circuit inhibits at least one of writing and erasing from being done on the second storage area.

Nonvolatile Semiconductor Memory Device

The anomalous leakage current I L in LPCVD polysilicon MOSFET's is attributed to field emission via grain-boundary traps in the (front) surface depletion region at the drain, and an analytic model that describes the strong dependences of I L on the gate and drain voltages is developed. The model predictions are consistent with measured current-voltage characteristics. Physical insight afforded by the model implies device design modifications to control and reduce I L , and indicates when the back-surface leakage component is significant.

Anomalous leakage current in LPCVD PolySilicon MOSFET's

Antiferromagnetism and superconductivity are both fundamental and common states of matter. In many strongly correlated systems, including the high Tc cuprates, the heavy fermion compounds and the organic superconductors, they occur next to each other in the phase diagram and influence each other's physical properties. The SO(5) theory unifies these two basic states of matter by a symmetry principle and describes their rich phenomenology through a single low energy effective model. In this paper, we review the framework of the SO(5) theory, and its detailed comparison with numerical and experimental results.

/pdf/so-5-theory-of-antiferromagnetism-and-superconductivity-3qzte27w8u.pdf

SO(5) theory of antiferromagnetism and superconductivity

The effect of ambient oxygen pressure on the synthesis of epitaxial YBa2Cu3O7−x films on (100) SrTiO3 substrates by post‐deposition annealing of amorphous precursor films was studied for oxygen partial pressures pO2 between 1.0 and 8.0×10−5 atm and annealing temperatures between 890 and 650 °C. A pO2−1/T diagram containing recent literature data regarding YBa2Cu3O7−x oxygen stoichiometry, phase stability, and liquid‐phase formation was compiled to provide guidance for the selection and interpretation of annealing conditions. The results evidence a strong dependency of growth properties on the oxygen pressure with enhanced c‐oriented epitaxy at lower pO2 values. A particularly interesting result is the formation of predominantly c‐oriented films at 740 °C and pO2=2.6×10−4 atm (0.2 Torr). Similar to YBa2Cu3O7−x films produced by in situ laser ablation at the same temperature and oxygen pressure, the films exhibited low ion channeling yields (χmin<0.1) and a dense (smooth) surface morphology, while critical ...

Effect of oxygen pressure on the synthesis of YBa2Cu3O7-x thin films by post-deposition annealing

A sandwich‐type all‐oxide Josephson junction consisting of an a‐axis oriented YBa2Cu3O7−δ/PrBa2Cu3O7−δ’/YBa2Cu3O7−δ structure has been realized and its Josephson characteristics experimentally investigated. Almost all the fabricated junctions showed the Josephson characteristics, including a resistively shunted junction (RSJ)‐like current‐voltage characteristic and a Fraunhofer‐like magnetic‐field dependence of the critical current. The obtained maximum values of the critical‐current density jc and the IcRn value were 110 A/cm2 and 80 μV, respectively, for a 50‐nm‐thick PBCO interlayer at 3 K. Besides, the temperature dependencies of the critical current and the normal resistance were measured. Ic was proportional to exp(− aT1/2), where a is a constant.

Josephson characteristics in a‐axis oriented YBa2Cu3O7−δ/PrBa2Cu3O7−δ’/YBa2Cu3O7−δ junctions

The characterization of polycrystalline silicon MOS transistors and its film properties are studied, with special emphasis on the relationship between crystalline defects and carrier transport phenomena An increase in mobility with gate field in polycrystalline silicon MOS transistors and also with doping concentration in polycrystalline silicon films is observed These phenomena are interpreted as space charge scattering effects caused by a high density of dislocations in the films U-shaped drain current vs gate voltage curves are observed both in p-channel and n-channel polycrystalline silicon MOS transistors The anomalous drain current in the accumulation region is interpreted as junction breakdown at the drain edge caused by crystalline imperfections in the films

https://iopscience.iop.org/article/10.1143/JJAP.21.1472/pdf

Characterization of Polycrystalline Silicon MOS Transistors and Its Film Properties. I

An electrically erasable and programmable read only memory comprises a semiconductor substrate of a first conductivity type, source and drain regions both of a second conductivity type formed in the surface of said semiconductor substrate, a gate insulation film formed on that section of the surface of said substrate which includes a channel region defined between said source and drain regions, a first diffusion region of the second conductivity type, part of which is formed in said substrate and contacts said drain region and which has a lower impurity concentration than said drain region, a first insulation film formed on said first diffusion region, a floating gate formed on said gate insulation film, part of which extends over said first insulation film, a second diffusion region of the first conductivity type formed in the surface of said first diffusion region which lies near said extension of the floating gate, a third diffusion region of the first conductivity type formed in the surface of said first diffusion region, a second insulation film covering said floating gate, and a control gate crossing at least that section of the surface of said second insulation layer which faces part of said floating gate.

Electrically erasable and programmable read only memory

The dependence of crystalline orientation in Y-Ba-Cu-O films on oxygen partial pressure and substrate temperature has been investigated for films prepared by magnetron sputtering on (100) SrTiO3 and (100) MgO substrates. The tendencies for preferential orientation were the same on both substrates. At low oxygen pressures, the c-axis was oriented perpendicularly to the film plane. In contrast, a/c-axis oriented films were formed at intermediate oxygen pressures, and the a-axis was oriented at high oxygen pressures. At higher temperatures, c-axis oriented films were formed, even at high oxygen pressures.

Effects of Oxygen Partial Pressure and Substrate Temperature on Crystalline Orientation in Y–Ba–Cu–O Films Prepared by Sputtering

The structural features of superconducting Y-Ba-Cu-O films prepared by reactive sputtering have been discussed in relation to the preparation conditions. Conductivity anisotropy and the anomalous diamagnetic response observed for the films have also been discussed.

Yoshihisa Mizutani

Papers

Josephson characteristics in a‐axis oriented YBa2Cu3O7−δ/PrBa2Cu3O7−δ’/YBa2Cu3O7−δ junctions

Characterization of Polycrystalline Silicon MOS Transistors and Its Film Properties. I

Electrically erasable and programmable read only memory

Effects of Oxygen Partial Pressure and Substrate Temperature on Crystalline Orientation in Y–Ba–Cu–O Films Prepared by Sputtering

Structural Features and Superconducting Properties of As-Grown Y–Ba–Cu–O Films