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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Proceedings ArticleDOI
Computer modeling of a subnanosecond transistor including high level injection effects
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Proceedings ArticleDOI
Advantages of SiGe-pnp over Si-pnp for analog and RF enhanced CBiCMOS and Complementary Bipolar design usage
Jeff A. Babcock,Joel M. Halbert,Hiroshi Yasuda,Alexei Sadovnikov,Jonggook Kim,Alan Buchholz,Robert Malone,Marco Corsi,Greg Cestra,Mattias Dahlstrom +9 more
TL;DR: In this paper, the evolution of silicon and silicon-germanium pnp transistors is reviewed with a view on device parametric parameters that help gage the usefulness of these devices in analog and RF design.
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Bipolar Junction Transistors
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Improved HCI of Embedded High Voltage EDNMOS in Advanced CMOS Process
Liu Junwen,Chen Hualun,Chen Yu +2 more
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Enhanced fT and linearity performance of InGaP/GaAs HBTs using a non-uniform doping collector
Che Ming Wang,Yue Ming Hsin +1 more
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References
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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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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.