Table Of ContentSWITCHING IN
SEMICONDUCTOR
DIODES
MONOGRAPHS IN SEMICONDUCTOR PHYSICS
Volume 1:
Heavily Doped Semiconductors
by Viktor I. Fistul'
Volume 2:
Liquid Semiconductors
by V. M. Glazov, S. N. Chizhevskaya, and N. N. Glagoleva
Volume 3:
Semiconducting lI-VI, IV-VI, and V-VI Compounds
by N. Kh. Abrikosov, V. F. Bankina, L. V. Poretskaya,
L. E. Shelimova, and E. V. Skudnova
Volume 4:
Switching in Semiconductor Diodes
by Yu. R. Nosov
In preparation:
Semiconducting Lead Chalcogenides
by Yu. I. Ravich, B. A. Efimova, and I. A. Smirnov
Organie Semiconductors and Biopolymers
by L. I. Boguslavskii and A. V. Vannikov
SWITCHING IN
SEMICONDUCTOR
DIODES
Yurii R. Nosov
A. F. laffe Physicotechnical Institute
Leningrad, USSR
Translated from Russian by
Albin Tybulewicz
Editor, Soviet Physics-Semiconductors
<:E?
PLENUM PRESS • NEW YORK-LONDON • 1969
Yurii Romanovich Nosov was born in 1931, in Moscow. He gradu
ated in 1954 from the Physics Department of the M. V. Lomonosov
State University in Moscow. Since graduation, he has been engaged
in research on, and the design of, fast-response semiconductor pulse
diodes. In 1964, Nosov was awarded the degree of Candidate of
Technical Sciences by the A. F. loffe Physicotechnical Institute in
Leningrad. In 1965, he was promoted to the rank of senior scientist
in the specialty of electronic technology and devices. He is a mem
ber of the All-Union Society "Znanie," the A. S. Popov Scientific and
Technical Society for Radio Engineering and Electrical Communi-
cations, and of the ''Trud'' Sporting Association.
The original Russian text was published by Nauka Press, Moscow,
in 1968 as part of aseries on "Physics of Semiconductors and Semi
conducting Devices" and has been revised by the author for this
English edition.
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V IMPUL'SNOM REZHIME
Library 01 Congress Catalog Card Number 69-12535
ISBN 978-1-4684-8195-2 ISBN 978-1-4684-8193-8 (eBook)
DOI 10.1 007/978-1-4684-8193-8
© 1969 Plenum Press, New York
Softcover reprint of the hardcover 1s t edition 1969
A Division of Plenum Publishing Corporation
227 West 17th Street, New York, N. Y. 10011
United Kingdom edition published by Plenum Press, London
A Division of Plenum Publishing Company, Ltd.
Donington House, 30 Norfolk Street, London W.C. 2, England
All rights reserved
No part of this publication may be reproduced in any form
without written permission from the publisher
Preface to the American Edition
It gives me great pleasure to learn that this book, whose ori
gin owes much to the work of American scientists and engineers on
semiconductor technology, will reach American and other English
speaking readers.
I am grateful to Plenum Publishing Corporation for arranging
the American edition of this book and to Mr. Albin Tybulewicz for
his translation,
September 5, 1968 Yu. R. Nosov
v
Preface to the Russian Edition
One of the most important applications of semiconductor
diodes is their use in electronic pulse circuits.
The response of these diodes under switching conditions is
governed by the phenomena of accumulation and dispersal of non
equlibrium carriers, which are also observed in other p-n junction
devices.
It was found in the late 1940's that when point-contact ger
manium diodes were used in circuits through which short (several
tenths of a microsecond) electrical pulses were being passed, the
1 effective reverse resistance of these diodes decreased considerably
below the static value. Further studies showed that when a diode
was switched rapidly from the forward to the reverse direction, an
anomalously large reverse current flowed for some time.
In view of the importance of this phenomenon in the efforts
to reduce the response time of pulse circuits, many investigations
of the phenomenon were carried out and these investigations pro
vided the basis of a theory of transient processes in semiconductor
diodes.
It was established that the rate of dispersal of nonequilibrium
carriers, accumulated in the diode base, is governed by the proper
ties of the diode itself, as weIl as by the switching conditions.
This made it possible to reduce the response time of the diodes
and to d~velop methods for the determination of the optimal opera
ting conditions of these devices in pulse circuits. Later it was
found that this theory of transient processes had other important
applications, in addition to its usefulness in reducing the response
time of diodes and of pulse diode circuits.
vii
viii PREFACE TO THE RUSSIAN EDITION
This theory has served as the corner-stone of the studies of
the processes of the accumulation and dispersal of excess charges
in transistors and thyristors and, through its application, the upper
frequency limit of these devices has been increased. Secondly, the
theory has stimulated the development of such new devices as
charge-storage diodes and sorne special types of varactor forfre
quency multiplication.
The development of the theory of transient processes in diodes
has made it possible condiderably to extend investigations of re
laxation processes in semiconductors under nonequilibrium condi
tions, in particular, the recombination of nonequilibrium carriers.
The main purpose of this book is to acquaint the reader with
the physical basis of the operation of a semiconductor diode under
pulse conditions, and to give, whenever possible, quantitative rela
tionships describing transients in diodes.
The variety of various possible switching conditions in cir
cuits is practically infinite and, therefore, it has not been possible
to discuss all the conditions. Instead, adescription is given of the
most general mathematical methods for solving the equations des
cribing transient processes , and these methods are presented in
such a way as to enable the reader to analyze those pulse conditions
which are not discussed in this book.
A model of a planar diode with a semi-infinite base is dis
cussed in the greatest detail. This is done because the basic for
mulas for this model are the simplest and clearest; moreover, the
most important relationships obtained for the planar diode are
found to apply approximately to other diodes.
Problems associated with the application of the theory of
transient processes in the practical design of fast-response diodes
and of circuits incorporating such diodes are not discussed in this
book; readers interested in the design aspects are directed to spe
cialist texts on this subject [62,103, 166].
The list of references is reasonably complete but it does not
cover fully all the numerous applications.
For convenience, the symbols used are explained in the text
and are also collected together in a separate list.
PREFACE '1'0 THE RUSSIAN EDITION ix
The author is grateful to Candidate of Technical Sciences
L. S. Berman for reading the manuseript and for his valuable ad
viee; to Candidate of Teehnical Seienees O. K. Mokeevfordiseuss
ing some of the problems eondidered in this book; and to L. V. Gu
byrin and L. A. Kuranova for their help in writing Chapter Irr and
seleeting the literature relevant to this ehapter. The author 1s
r.
mueh indebted to S. Egorova without whose help in the prepara
tion of the manuseript this book would not have been published.
Contents
Notation ... xiii
CHAPTER I. Basic Electronics of the Switching
Processes in Semiconductor p-n Junctions . 1
§1. Introduction ........•...•... 1
§2. Transformation of Basic Equations 4
§3. Solution of the Diffusion Equation (at Low
Injection Leve ls) ................ . 10
CHAPTER II. Switching in a Planar Diode 25
§4. Transient Processes without a Limiting
Resistance in the Diode Circuit .. 25
§5. Switching of a Diode Circuit with a
Limiting Resistance . . . . . . . . .. . ........ . 38
§6. Switching of a Diode Circuit with an
Infinite Resistance ........... . 53
§7. Small-Signal Transient Characteristics
of a Diode ................... . 66
§8. Methods for the Observation of Transient
Processes in Diodes ..... 69
§9. Main Experimental Results ...... . 82
CHAPTER III. Planar Diode with a Thin Base. 96
§10. Steady-State Distribution of Holes in
the Base .................. . 96
§11. Switching without a Resistance in the
Diode Circuit ............... . 107
§12. Switching in a Circuit with a Limiting
Resistance .............. . 118
§13. General Estimate of the Response
of a Thin-Base Diode ........ . 127
xi
xii CONTENTS
CHAPTER IV. Transient Processes in a Diode
with a Small-Area Rectifying Contact ....... . 130
§14. Ideal Model of a Point-Contact Diode. . . . . . 131
§15. Transient Conditions. . . . . . . . . . . . . . . 141
§16. Experimental Investigations . . . . . . . . . . 153
CHAPTER V. Effect of an Electric Field in a
Diode Base on Transient Processes ....... . 160
§17. Built-in Internal Field in a Diode Base. 160
§18. Forward-Biased Diode with a Built-in
Field ..................•.... 165
§19. First (Recovery) Phase. . . . . . . . . . . . . . . . 171
§20. Reverse Current Decay . . . . . . . . . . . . . . . 175
CHAPTER VI. Transient Processes in Diodes
During the Passage of a Forward Current
Pulse ............................... . 179
§21. Introduction .................... . 179
§22. Establishment of a Forward Resistance
in a Planar Diode ............. . 183
§23. Establishment of a Forward Voltage
Across a Diode with a Hemispherical
p-n Junction ............... . 191
CHAPTER VII. Transient Processes in
Semiconductor Diodes and Fundamentals
of Recombination Theory ..... 197
§24. Introduction .................... . 197
§25. Lifetime of Holes under Various
Recombination Conditions ................ 201
§26. Influence of Trapping Levels on
Transient Processes in Diodes . . . . . . . . . . . .. 209
§27. Recombination Properties of Gold-Doped
Germanium and Silicon • • . . . . . . . . • . . • . . .. 214
Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 226
Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 231
