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We present experimental studies of the current pumped through a dynamic quantum dot over a wide range of magnetic fields. At low fields we observe a repeatable structure indicating increased confinement of the electrons in the dynamic dot. At higher fields (B>5T), we observe a structure which changes markedly from device to device suggesting that in this regime the transport is sensitive to local disorder. The results are significant for the development of dynamic quantum dot pumps as quantum standards of electrical current. [ABSTRACT FROM AUTHOR]

High dielectric constant hafnium oxide films were formed by electron beam (e-beam) evaporation on HF last terminated silicon (100) wafers. We report on the influence of low energy argon plasma (∼70 eV) and oxygen flow rate on the electrical, chemical, and structural properties of metal-insulator-silicon structures incorporating these e-beam deposited HfO2 films. The use of the film-densifying low energy argon plasma during the deposition results in an increase in the equivalent oxide thickness (EOT) values. We employ high resolution transmission electron microscopy (HRTEM), x-ray photoelectron spectroscopy (XPS), and medium energy ion scattering experiments to investigate and understand the mechanisms leading to the EOT increase. We demonstrate very good agreement between the interfacial silicon oxide thicknesses derived independently from XPS and HRTEM measurements. We find that the e-beam evaporation technique enabled us to control the SiOx interfacial layer thickness down to ∼6 Å. Very low leakage current density (<10-4 A/cm2) is measured at flatband voltage +1 V into accumulation for an estimated EOT of 10.9±0.1 Å. Based on a combined HRTEM and capacitance-voltage (CV) analysis, employing a quantum-mechanical CV fitting procedure, we determine the dielectric constant (k) of HfO2 films, and associated interfacial SiOx layers, formed under various processing conditions. The k values are found to be 21.2 for HfO2 and 6.3 for the thinnest (∼6 Å) SiOx interfacial layer. The cross-wafer variations in the physical and electrical properties of the HfO2 films are presented. [ABSTRACT FROM AUTHOR]

The effect of low energy argon plasma and oxygen flow rate on the electrical, chemical and structural properties of metal-insulator-silicon structures incorporating the electron beam (e-beam) deposited Hf[O.sub.2] films is examined. The results have shown the potential of the e-beam deposition method to form suitable low equivalent oxide thickness (EOT) films for examining fundamental properties of thin Hf[O.sub.2] layers and to screen other alternative high-k dielectric candidates for metal-oxide-semiconductor (MOS) applications.

Presents a study which examined the band alignment in gallium arsenide:(aluminum, gallium)arsenic heterostructures over a full range of alloy composition. Experiment; Measurement technique; Discussion.

Presents a study that described the measurement of the energy band discontinuities in gallium arsenide:(Al,Ga)arsenic heterostructures. Parameter that influences the electrical and optical properties of a heterojunction; Description of the structure used in the study; Illustration of a typical n-type structure.

Presents a study which calculated the temperature dependence of the carrier density in epitaxial layers of semiconductors deposited on semi-insulating substrates when the potentials at the surface and the substrate interface are pinned. Theoretical background; Comparison of theory with experiment; Conclusion.

Presents a study that analyzed the electrical properties and microstructure of indium arsenide ohmic contacts to n-type gallium arsenide semiconductors. Measurement of the contact resistance; Comparison of contacts prepared by sputter-deposition and evaporation; Effect of intervening oxide layer on indium arsenide and gallium arsenide interaction.

Presents a theoretical and experimental study of the longitudinal uniaxial stress dependence of I-V characteristics in GaAs-Al[subx]Ga[sub1-x]As-GaAs heterojunction barriers. Procedure to extract parameters for theoretical calculations; Dependence of the I-V characteristics on uniaxial stress in the direction perpendicular to the heterojunction plane; Usefulness of uniaxial stress in elucidating the transport mechanisms in heterojunction barriers.

Presents a study which conducted a noise spectroscopy of semiconductor deep level centers in gallium arsenide-aluminum[sub x]gallium[sub 1-x]arsenide heterostructures. Description of the model; Experiment; Results and discussion.

Presents information on a study which analyzed measurements of the capture barrier for the DX center in silicon-doped Al[subx]Ga[sub1-x]As as a function of the alloy composition. Fabrication of the samples from material grown by molecular beam epitaxy; Results of the deep-level transient spectroscopy measurements; Details of trapping kinetics in Al[sub0.35]Ga[sub0.65]As.

Discusses the effect of DX centers on the electrical characteristics of p-n heterojunctions in heterojunction bipolar transistors. Range of voltage over which the capacitance is constant; Transient time of electrons across the depletion region.