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Journal ArticleDOI

A theory of transistor cutoff frequency (f T ) falloff at high current densities

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TLDR
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.

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Citations
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Proceedings ArticleDOI

Integrated PIN photodiodes in high-performance BiCMOS technology

TL;DR: In this paper, a PIN photodiode combining high responsivity, fast response and low capacitance in BiCMOS technology is presented, having no verifiable influence on the transistor parameters.
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Modeling of bipolar transistor using integral charge-control model with application to third-order distortion studies

TL;DR: In this paper, a detailed characterization of a high-frequency silicon bipolar transistor using the integral charge control model (ICM) with sufficient accuracy to allow calculation of intermodulation distortion is presented.
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Silicon Germanium heterojunction bipolar transistor ESD power clamps and the Johnson Limit

TL;DR: In this paper, a SiGe-based ESD power clamp was constructed using epitaxial base pseudomorphic Silicon Germanium heterojunction transistors in a common collector Darlington configuration.
Proceedings ArticleDOI

Electrostatic discharge and high current pulse characterization of epitaxial-base silicon-germanium heterojunction bipolar transistors

TL;DR: In this article, the authors investigated high-current and electrostatic discharge (ESD) phenomenon in pseudomorphic epitaxial base silicon-germanium (SiGe) heterojunction bipolar transistors (HBT).
Journal ArticleDOI

Influence of Concurrent Electrothermal and Avalanche Effects on the Safe Operating Area of Multifinger Bipolar Transistors

TL;DR: In this article, the impact of the concurrent action of electrothermal and avalanche effects on the reduction of the safe operating area is experimentally investigated for a wide number of single-, two-, and three-finger bipolar transistors fabricated in SiGe, GaAs, and silicon-on-glass technologies.
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 ${E}^{-}\frac{1}{2}}$.
Journal ArticleDOI

The Dependence of Transistor Parameters on the Distribution of Base Layer Resistivity

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.