Journal ArticleDOI
A theory of transistor cutoff frequency (f T ) falloff at high current densities
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In this paper, it was shown that the observed falloff in the f T of a transistor at high currents is due to the spreading of the neutral base layer into the collector region of the device at high current densities.Abstract:
It is shown that the observed falloff in the f T of a transistor at high currents is due to the spreading of the neutral base layer into the collector region of the device at high current densities. The base layer spreading mechanism derives from an analysis of the effect of the current-dependent buildup of the mobile-carrier space-charge density in the collector transition layer. Calculations show that at sufficiently high collector current levels, the mobile space-charge density in the collector transition layer cannot be considered negligible in comparison to the fixed charge density of that region. The over-all effect of taking the mobile space charge into account in analyzing the collector transition region is that, at high current densities, the transition region boundary adjacent to the neutral base layer is displaced toward the collector metal contact with increasing collector current. The attendant widening of the neutral base layer results in the observed, high-current falloff in f T . The application of this theory to transistor structures of both the alloy and mesa variety yields, in each case, calculated curves of f T vs I c which are in reasonably good agreement with experiment.read more
Citations
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Journal ArticleDOI
Radiation-hardened phototransistor
TL;DR: In this paper, a radiation-hardened, monolithic, silicon bipolar phototransistor has been developed and produced, which is ideal for applications requiring a radiationhardened optocoupler.
Journal ArticleDOI
An MOS Modeling Hierarchy including Radiation Effects
D. R. Alexander,R. M. Turfler +1 more
TL;DR: A hierarchy of modeling procedures for MOS transistors, circuit blocks, and integrated circuits which include the effects of total dose radiation and photocurrent response was developed for use with the SCEPTRE circuit analysis program, but the techniques are suitable for other modern computer aided analysis programs as discussed by the authors.
Journal Article
Analysis of quasi-saturation phenomena for SiGe double heterojunction bipolar transistors
Gagan Khanduri,B.S. Panwar +1 more
TL;DR: In this article, a high-voltage current-switching NPN SiGe double-heterojunction bipolar transistor (DHBT) has been analyzed and simulated using two-dimensional device simulator MEDICI, including conductvity modulation, quasi-saturation phenomenon and effect of valence band offset for holes in a highvoltage SiGe DHBT and is compared with a conventional Si bipolar junction transistor (Si BJT).
Proceedings ArticleDOI
A closed-form analysis of f/sub T/ for the bipolar transistor down to liquid nitrogen temperature
TL;DR: In this paper, a simple closed-form expression for f/sub T/ (cutoff frequency) down to liquid nitrogen temperature has been determined by examining the emitter-collector transit time, t/sub ec/, where t /sub ec/ = 1/(2 pi t/ sub ec/).
References
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Journal ArticleDOI
The theory of p-n junctions in semiconductors and p-n junction transistors
TL;DR: The theory of potential distribution and rectification for p-n junctions is developed with emphasis on germanium, resulting in an admittance for a simple case varying as (1 + iωτ p )1/2 where τ p is the lifetime of a hole in the n-region.
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Mobility of Holes and Electrons in High Electric Fields
TL;DR: In this paper, the field dependence of mobility has been determined for electrons and holes in both germanium and silicon, and the observed critical field at 298\ifmmode^\circ\else\textdegree\fi{}K beyond which $\ensuremath{\mu}$ varies as ${E}^{-}\frac{1}{2}}$.
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The Dependence of Transistor Parameters on the Distribution of Base Layer Resistivity
J. L. Moll,I. M. Ross +1 more
TL;DR: In this article, a method of analyzing transistor behavior for any base-layer impurity distribution is presented, in particular expressions for emitter efficiency, transverse sheet resistance R, transit time, and frequency cut-off f?.
Journal ArticleDOI
Structure-Determined Gain-Band Product of Junction Triode Transistors
TL;DR: In this article, the authors compared the power gain of the junction triode with those of the field effect transistor and the analog transistor and showed that the gain-band product is nearly independent of the particular alpha cutoff frequency selected.