Table Of ContentMercury Cadmium
Telluride Imagers
A Patent-oriented Survey
HANDBOOK OF SENSORS AND ACTUATORS
Series Editor: S. Middelhoek, Delft University of Technology,
The Netherlands
Volume 1 Thick Film Sensors (edited by M. Prudenziati)
Volume 2 Solid State Magnetic Sensors (by C.S. Roumenin)
Volume 3 Intelligent Sensors (edited by H. Yamasaki)
Volume 4 Semiconductor Sensors in Physico-Chemical
Studies (edited by L. Yu. Kupriyanov)
Volume 5 Mercury Cadmium Telluricle Imagers
(A. Onshage)
HANDBOOK OF SENSORS AND ACTUATORS 5
Mercury Cadmium
Tel luride I magers
A Patent-oriented Survey
Anders C. Onshage
European Patent Office
The Hague, The Netherlands
1997
ELSEVIER
Amsterdam - Lausanne - New York - Oxford - Shannon - Tokyo
ELSEVIER SCIENCE B.V.
Sara Burgerhartstraat 25
P.O. Box 211, 1000 AE Amsterdam,
The Netherlands
ISBN: 0 444 82790 0
(cid:14)91 997 Elsevier Science B.V. All rights reserved.
No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any
means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the
publisher, Elsevier Science B.V., Copyright & Permissions Department, P.O. Box 521, 1000 AM Amsterdam,
The Netherlands.
Special regulations for readers in the U.S.A. - This publication has been registered with the Copyright Clearance
Center Inc. (CCC), 222 Rosewood Drive, Danvers, MA 01923. Information can be obtained from the CCC about
conditions under which photocopies of parts of this publication may be made in the U.S.A. All other copyright
questions, including photocopying outside of the U.S.A., should be referred to the publisher, Elsevier Science B.V.
No responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of
products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions
or ideas contained in the material herein.
This book is printed on acid-free paper.
Printed in The Netherlands
Introduction to .the Series
The arrival of integrated circuits with very good performance/price ratios and relatively low-
cost microprocessors and memories has had a profound influence on many areas of technical
endeavour. Also in the measurement and control field, modern electronic circuits were
introduced on a large scale leading to very sophisticated systems and novel solutions.
However, in these measurement and control systems, quite often sensors and actuators were
applied that were conceived many decades ago. Consequently, it became necessary to improve
these devices in such a way that their performancedpdce ratios would approach that of modem
electronic circuits.
This demand for new devices initiated worldwide research and development programs in the
field of "sensors and actuators'. Many generic sensor technologies were examined, from
which the thin- and thick-film, glass fiber, metal oxides, polymers, quartz and silicon
technologies are the most prominent.
A growing number of publications on this topic started to appear in a wide variety of
scientific journals until, in 1981, the scientific journal Sensors and Actuators was initiated.
Since then, it has become the main journal in this field.
When the development of a scientific field expands, the need for handbooks arises, wherein
the information that appeared earlier in journals and conference proee~ings is systematically
and selectively presented. The sensor and actuator field is now in this position. For this
reason, Elsevier Science took the initiative to develop a series of handbooks with the name
"Handbook of Sensors and Actuators" which will contain the most meaningful background
material that is important for the sensor and actuator field. Titles like Fundamentals of
Transducers, Thick Film Sensors, Magnetic Sensors, Micromachining, Piezoelectric Crystal
Sensors, Robot Sensors and Intelligent Sensors will be part of this series.
The series will contain handbooks compiled by only one author, and handbooks written by
many authors, where one or more editors bear the responsibility for bringing together topics
and authors. Great care was given to the selection of these authors and editors. They are all
well known scientists in the field of sensors and actuators and all have impressive
international reputations.
Elsevier Science and I, as Editor of the series, hope that these handbooks will receive a
positive response from the sensor and actuator community and we expect that the series will
be of great use to the many scientists and engineers working in this exciting field.
Simon Middelhoek
Mercury. Cadmium Teiluride Imagers
Summary
The evolution of imager structures using Mercury Cadmium Telluride (HgCdTe) is described
based on published patents and patent applications. The book is divided into two parts. The
first describes monolithic arrays, with the detector elements and read-out means integrated in
the same semiconductor body. The second part describes hybrid arrays, with the detector
elements and the read-out means formed in separate semiconductor bodies.
The types of monolithic arrays discussed are charge coupled device imagers, ambipolar driR
field imagers, static induction transistor imagers, charge injection device imagers and charge
imaging matrices. The part on hybrid arrays has specific chapters on flip-chip arrangements, Z-
technology arrangements, and arrays with the detector array directly contacting the read-out
chip. The remaining hybrid arrays are separated according to whether the detector elements are
provided with individual read-out leads or not.
The cited documents are presented with an introductory part followed by a descriptive part
which in most cases includes one or more figures. An overview of the subject of this book may
be aquired by reading only the introductory parts in combination with the figures.
A patent number index with information about the patent applicants, inventors, priorities and
patent-families, an inventor index, a company index, and a subject index can be found at the
end of the book.
VI.oI
Preface
This book is an attempt to describe the evolution of mercury cadmium telluride (HgCdTe)
imager structures based on published patents and patent applications. Most of the patent
documents cited in this book originate from the part of the systematic documentation at the
European Patent Office (EPO) which corresponds to the International Patent Classification
(IPC) H01L27/14
Focus has been directed to the structures of the imagers. The steps of manufacturing of the
structures have been included when steps of specific interest have been disclosed. It has been
necessary to exclude documents not explicitly mentioning mercury cadmium telluride to reduce
the material to a manageable size. It should be noted that no verification of the feasibility of a
device or its operation is needed to render it patentable. The analysis of certain Japanese patent
applications have been limited to the published Patent Abstract of Japan.
The patent number, the name of the applicant and the date of publication are indicated for each
document cited in the book. A patent number index, an inventors index, a company index and a
subject index is found at the end of the book.
It is not unusual that a patent application has been filed in several countries referring to a
common first filing i.e. priority. These applications are said to belong to the same patent-
family. In this book English-speaking documents of the patent-families have been selected
provided it has been possible. The patent numbers or patent application numbers of other
documents belonging to the same patent-family as a cited document may be found in the patent
number index at the end of the book.
I HO1L27/14: Devices consisting of a plurality of semiconductor or other solid-state components formed in or
on a common substrate, including semiconductor components sensitive to infra-red radiation, light,
electromagnetic radiation of a shorter wavelength, or corpuscular radiation of a shorter wavelength, or
corpuscular radiation and adapted for the conversion of the energy of such radiation into electrical energy or
for the control of electrical energy by such radiation.
viii Mercury Cadmium Telluride Imagers
The book is separated into a first part with monolithic arrays and a second part with hybrid
arrays. Each part comprises five chapters. The documents of each chapter are placed in a
chronological order with the documents with earliest priority placed first. The documents are
separated by a star '*' Sometimes a document has been placed at a position which is earlier
than that which corresponds to its priority date. This has been done when the document shares
basic features with a document already presented in the chapter. The document then follows
directly after the earlier document and the documents are separated by two stars'* *'
I would like to express my appreciation to all the people who have assisted me in this work and
especially to S. Behmo and A. Cardon, Directors at the EPO, L.J.L. Fransen, S. Greene, P.
Gori and A. Visentin, Examiners at the EPO.
It is my hope that this monography will serve as a useful summary of the patents and patent
applications in the field of mercury cadmium telluride imagers.
Rij swijk, 1995
A. C. Onshage
Contents
Introduction xi
Part One: Monolithic Arrays
Detector elements and read-out means are provided in the samq
semiconductor body.
1.1 ChargeC oupled Device Imagers
1.2 AmbipolarD rift Field Imagers 21
1.3 StaticI nduction Transistor Imagers 39
1.4 ChargeI njection Device Imagers 49
1.5 ChargeI maging Matrices 71
Part Two: Hybrid Arrays 83
Detector elements and read-out means are provided in separate
semiconductor bodies.
2.1 Detector Arrays with Individual Detector Element Read-Out Leads 85
Detector elements are provided with individual read-out leads
formed in or on a non-active supporting substrate.
2.2 Detector Arrays without Individual Detector Element Read-Out Leads 123
Individual detector elements are provided with bump connectors or
with no connectors at all.
- Cross-TalkP reventing Measures 202
- Passivationa nd Leakage Current Preventing Measures 253
2.3 Flip-ChipA rrangements 269
- ThermalS tress Preventing Measures 289
2.4 Z-TechnologyA rrangements 309
2.5 Detector Arrays Directly Contacting the Read-Out Chip 329
- Connectionsm ade by Through Hole Technologies 374
Patent Number Index 401
Inventor Index 421
Company Index 433
Subject Index 437
