Scientific and Technical Aerospace Reports Volume 38 July 28, 2000

This paper presents a physics-based model describing the current-induced formation of a parasitic barrier in the conduction
band at the base collector heterojunction in npn SiGe heterojunction bipolar transistors (HBTs). Due to the valence band discontinuity
DELTA E(sub v), hole injection into the collector at the onset of base pushout is impeded, which gives rise to formation of
a barrier to electron transport which degrades the device’s high frequency performance. In this paper, we present results from an
analytical model for the height of the barrier calculated from the device’s structure as a function of the collector junction bias and
collector current density.
Author
Bipolar Transistors; Conduction Bands; Heterojunctions; Silicon; Germanium; Electrophysics; Semiconductor Devices; Barrier
Layers
20000063515 National Inst. of Standards and Technology, Electronics and Electrical Engineering Lab., Gaithersburg, MD USA
NIST Electronics and Electrical Engineering Laboratory and the Development of Its Semiconductor Program: A Presentation
to the Standards Alumni Association
French, J. C.; Feb. 1999; 58p
Report No.(s): PB2000-105433; NISTIR-6507; No Copyright; Avail: CASI; A04, Hardcopy; A01, Microfiche
The report is a Presentation to the Standards Alumni Association by Judson C. French, Director, Electronics and Electrical
Engineering Laboratory (EEEL). EEEL’s formal mission is to promote U.S. economic growth through improved competitiveness,
by providing measurement capability of high economic impact focused primarily on the needs of U.S. electronics and electrical
equipment industries. EEEL does this by providing measurement research and services, principally in the authors’ five technical
divisions. It covers in the Electricity Division the provision of the Nation’s basic, primary electrical standards, and support for
electronic instrumentation, the electrical utilities, video technologies and electronic product data exchange, and, covers in the
other divisions, semiconductor electronics, radio-frequency and microwave and millimeter wave signals and interference, superconductors,
magnetics, and optoelectronics.
NTIS
Electrical Engineering; Semiconductors (Materials); Superconductors (Materials); Product Development
20000064047 Georgia Inst. of Tech., Atlanta, GA USA
Process Characterization of Non-Stoichiometric Material Growth Final Report, 1 Jun. 1996 - 31 May 1999
Brown, April S.; May, Gary; May 1999; 12p; In English
Contract(s)/Grant(s): F49620-96-1-0197
Report No.(s): AD-A376202; FR-3; AFRL-SR-BL-TR-00-0119; No Copyright; Avail: CASI; A01, Microfiche; A03, Hardcopy
This project addresses characterization of the Molecular Beam Epitaxy (MBE) process utilizing a Statistical Experiment
Design (SED) approach and then building models. This approach is applied to GaAs-based materials, InP-based materials, and
GaN-based materials, and to non-stoichiometric Be-doping InGaAs materials. The model responses are related to known physical
effects for the growth of these materials. In addition, new phenomena are uncovered.
DTIC
Molecular Beam Epitaxy; Experiment Design
20000064117 Joint Inst. for Nuclear Research, Frank Lab. of Neutron Physics, Dubna, USSR
Twinned structure of La2CuO4 crystals
Balagurov, A. M.; Beskrovnyj, A. I.; Pomyakushin, V.; Simkin, V. G.; Bagautdinov, B.; Dec. 31, 1998; 19p; In Russian; In English
Report No.(s): DE99-608002; JINR-R-14-98-9; No Copyright; Avail: Department of Energy Information Bridge
The twin microstructure of La2CuO(4+(delta)) superconducting crystals with (delta) from 0.02 to 0.04 has been studied by
neutron and x-ray scanning of reciprocal space as well as by high resolution neutron diffraction. The studied crystals belonged
to two different types with respect to the oxygen mobility: with and without macroscopic phase separation. It has been shown that
for both types of crystals the twinning is accompanied by arising of practically the same systems of domains (transformational
twins). Configuration of the domains is so, that the boundaries between them are mainly coherent. In the macroscopically phase
separated La2CuO(4+(delta)) crystals the volume of distorted and tense areas is most probably small, that would be the factor,
which furthers to oxygen diffusion.
NTIS
Twinning; Crystal Lattices; Microstructure; Crystal Structure
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