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The quantum corrections to the conductivity of the high-mobility multilayer p-Ge/Ge(1-x)Si(x) heterostructures are investigated at T (0.1 : 20)K in magnefic fields B up to 1.5 T. The observed negative magnetoresistance with logarithmic dependencies both on temperature and magnetic field for B > 0. 1 T is interpreted as the consequence of the particle-particle (hole-hole) attractive interaction in the Cooper channel., Pres: 6th Int Symp Nanostructures: Physics and Technology, St Petersburg, Russia. 22-26 Jun 1998. p477-480. This article is from ADA406591 Nanostructures: Physics and Technology International Symposium (6th) held in St. Petersburg, Russia on June 22-26, 1998 Proceedings

The temperature dependences of lateral conductivity and hole mobility in SiGe quantum well structures selectively doped with boron are presented. The boron A+ centers are found to exist and determine the low temperature conductivity. The activation energy of conductivity at higher temperatures is shown to be determined by the energy distance between strain split boron A0 levels. The model of two-stage excitation of free holes including the thermal activation of holes from the ground to split-off state and next tunneling into the valence band is proposed. The binding energy of A+ centers and the energy splitting of boron ground states by strain are found., This article is from ADA406591 Nanostructures: Physics and Technology International Symposium (6th) held in St. Petersburg, Russia on June 22-26, 1998 Proceedings

The transport properties of carriers in the inversion layer was studied by using the thick-gate uniform channel field MOS transistor. Using devices with sub-100nm channel lengths, we performed an extensive investigation of ballistic transport in inversion layer under uniform field condition. We experimentally address the effect of a wide range of parameters on the high-field transport of Inversion layer electrons and holes. Our findings point to electron velocity overshoot at room temperature, dependence of electron and hole saturation velocities on nitridation of the gate oxide, dependence of the high-field drift velocity on the effective vertical field, and relative insensitivity of electron and hole mobility and saturation velocity to moderate surface roughness.

In this period the main focus of the work was dedicated to the study of a superlattice under bias. Most of the previous experiments could not investigate the bias dependence of the superlattice current since the applied electric field was not varied in a controlled way. Our structure has the specific advantage that a defined voltage can be applied between base and collector. Therefore our work represents the first defined experiment of superlattice transport as a function of electric field across the superlattice. As a result we find that for negative bias the current is quenched quite rapidly and decreases to zero at the expected value of the localization electric field (5kV/cm). For positive bias a very promising behavior is found: up to an electric field of 1kV/cm a nearly constant current is observed which is an indication for electric field induced miniband transport. This observation which has to be confirmed with several samples, could be the first signature of a Bloch-type current in the superlattice.

The objective of this research is to study the thermal and electronic properties of isotopically enriched (28)Si epitaxial films which are potentially attractive for high density, high-speed electronic circuit applications. The natural abundance of Si is roughly 92.2% of (28)Si, 4.7% of (29)Si, and 3.1% of (30)Si, which is also roughly the composition of Si crystals currently used in industry. By removing the heavier isotopes (i.e., (29)Si and (30)Si), it is very likely that the enriched (28)Si crystal will have a much better thermal conductivity and carrier mobility, due to the reduction of the scattering centers arising from the heavy isotope 'impurities'. jg p.3

Partial Contents: LSI layout verification system using circuit simulation programs; Application of numerical simulation in the modeling of I.C. device structures; Discretization methods for the semiconductor equations; Two-dimensional numerical analysis of doping processes; Submicron device simulation; A singular perturbation analysis of discretisation methods for the parabolic semicondutor device equations; Two-dimensional analysis of the back region of I.B.C. silicon solar cells; Two dimensional simulation of VLSI processes: a solution using finite element method; The influence of various mobility models on the iteration process and solution of the basic semiconductor equations; Surface and bulk-dominaTED PUNCH-through in short-channel MOSFETS; Adaptation of stiff methods to simulation of impurity diffusion in semiconductors; Application of parabolic partial differential equations to semiconductor device modeling; Calculation of quasi-static device behavior with small computational burden; Modeling the body effect of a short channel MOSFET. Steady state numerical analysis of single carrier two dimensional semiconductor devices using the control area approximation; Carrier mobility at interfaces; Nonstatic modeling of submicron transistors; Numerical solutions of the electrical properties of GaAs/Al1-x GaxAs superlattices and heterojunctions; An accurate 2-d simulation program of MOS transistors using the finite element method, and interfaced to other process simulation programs; Numerical simulation of the phase memory in nonlinear active media with diffusion; Finite element modelling of junction terminations in reverse-biased semiconductor devices.

See also AD-A088 653.

Trans. of Iz Ak Nauk SSSR, Otdel. Tekh Nauk, Metallurgiya i Toplivo (News of the Academy of Sciences USSR, Department of Technical Sciences, Metallurgy and Fuel), (Russia), n1, p9-12, 8 Aug 58.