Journal ArticleDOI
A theory of transistor cutoff frequency (f T ) falloff at high current densities
Reads0
Chats0
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.read more
Citations
More filters
Journal ArticleDOI
1.5-W CW S-band GaInP/GaAs/GaInP double heterojunction bipolar transistor
Wen-Chau Liu,A. Khatibzadeh +1 more
TL;DR: The first large-signal power result from a double heterojunction bipolar transistor (DHBT) based on the GaInP/GaAs/GaInP material system was reported in this article.
Journal ArticleDOI
An analytical all-injection charge-based model for graded-base HBTs
TL;DR: In this article, an all-injection charge-based model suitable for implementation in computer aided design tools has been developed, where injected current, charge and recombination current components are formulated for all levels of injection base grading effect on current components, current gain and cutoff frequency in the high current regions are studied.
Journal ArticleDOI
Harnessing the base-pushout effect for ESD protection in bipolar and BiCMOS technologies ☆
TL;DR: In this paper, the impact of the base-pushout or Kirk-effect on the ESD characteristic of modern radio frequency (RF) NPN transistors is investigated, and concepts to exploit the base pushout effect for improved RF protection schemes are presented.
Journal ArticleDOI
An analytical model for the epitaxial bipolar transistor
B.L. Grung,R.M. Warner +1 more
TL;DR: In this article, the authors derived an analytical model that is based primarily on five assumptions: (1) the structure is approximately one-dimensional; (2) recombination is negligible in the base and collector quasi-neutral regions, and in the three space-charge regions; (3) high-current effects are negligible in emitter and n+-substrate regions; and (4) the Fletcher boundary conditions (or the Misawa boundary conditions) can be used for the three spaces charge regions.
Patent
Method of forming multiple layer collector structure for bipolar transistors
William Liu,Darrell G. Hill +1 more
TL;DR: In this paper, a multiple layer collector structure is provided which comprises a relatively thin, highly doped layer 12 and a relatively thick, low doped or non-intentionally Doped layer 14.
References
More filters
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.
Journal ArticleDOI
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
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.