Book Reviews

Semiconductors - Processed and Packaged

Materials for Electronic Packaging. Edited by Deborah D. L. Chung, Butter- worth-Heinemann, Oxford 1995, xiv, 368 pp.. hardcover, ISBN 0-7506-

Various kinds of materials and manu- facturing processes are used for construct- ing electronic packages. Both inorganic materials and organic polymers have been widely used as molding compounds, insu- lators, encapsulants, and adhesives for multi-chip modules (MCMs), ball-grid- arrays (BGAs) and chip-scale-packages (CSPs). Solders are also used for electrical connection in l-lip-chip bonding. Package reliability is strongly related to the prop- erties of materials and the entire assembly process. The interaction at the interfaces between different materials is important to assure long-term reliability from the ther- mal, mechanical, and chemical points of view.

This book consists of six parts divided into 16 chapters. All categories of materi- als used in electronic packages are re- viewed in Part 1 . The fundamentals of sol- derability, the failure mechanism, and the lifetime prediction of Pb-Sn solder joints are described in Part 2. Fluxless process- ing using a laser beam is also introduced. The microstructures on the interfaces be- tween metal and ceramics are depicted in detail. Advanced composite materials are described in Part 3. Fillers in a polymer play a role in controlling the coefficient of thermal expansion (CTE). Metal particles in a polymer function as EM1 shielding. A z-axis conductor for chip-to-substrate connection of surface mounted devices with area array bumps is described briefly.

Part 4 deals with the metallization pro- cess; thick-film materials and processing, the electroless copper deposition process, and thin-film processing are dmussed. Dielectrics for capacitors and resistor ma- terials for low TCR (temperature coeffi- cient of resistance) are included, along with the screen-printing process, firing process, and laser trimming process. The nano-line fabrication process using elec- troless copper in a fully planar fashion is introduced with the aim of ULSI applica-

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tion. After vapor deposition or sputtering, the adhesion strength is an important pa- rameter, so interface analysis methods such as AES (Auger electron spectros- copy) are introduced. In Part 5 , sili- cone-based polymers are introduced as encapsulants with excellent protection properties and as a replacement for her- metic sealing. The diamond process and its application for electronic packages are introduced, as diamond is the material with the highest thermal conductivity. Measurement methods for electrical, ther- mal, and mechanical properties of the ma- terials are described briefly in Part 6.

This book will be usehl for those who are interested in what kinds of materials are used in the packaging area. However, some topics. are treated too briefly in spite of their importance and recent topics are not covered due to space limitations; the inclusion of the epoxy mold compounds, the polyimide thin-film process, wiring printed boards using a build-up process, and Ph-free solder materials from the en- vironmental point of view would be appre- ciated.

Toshio Sudo Electronic Package and Assembly

Development Center Manufacturing and Engineering

Research Center Toshiba Corporation

33, Shin-Isogo-cho Yokohama 235 (Japan)

Semiconductors - Basic Data, 2nd ed. Edited by 0. Madelung, Springer, Ber- lin 1996, viii, 317 pp., hardcover,

The second revised edition of Senicon- ductors - Basic Datu contains a selection of important materials properties of semi- conductors taken from the Landolt- Bornstein volumes. The same editor of those larger volumes, Otfried Madelung, has also edited this collection. The aim of this book is to present the most important semiconductor parameters from those larger volumes in an inexpensive, compact source. Overall, it succeeds in this goal, but there are some omissions and outdated material that limit the usefulness of this volume for some scientists.

This book provides a fairly comprehen- sive coverage of many semiconductors. A vast amount of useful data is presented in only 317 pages. The first chapters cover group IV and 111-V semiconductors. For each semiconductor, various constants and relations are tabulated. Energy gaps, cal- culated band structures, elastic constants, and phonon dispersion relations are given. Also included are graphs of thermal and electrical (both hole and electron) conduc- tivities. A few optical constants, such as the index of refraction, are also included. In cases where they are known, diffusion coefficients and binding energies of impu- rities are also included. For all these val- ues, references to the original work are given. With such a large number of con- stants tabulated in a well-organized man- ner, this volume will be useful for scien- tists working with group IV or most III-V compounds.

However, some technologically impor- tant semiconductors are not covered, or have obsolete information. In particular, the information on the nitrides is out of date. The section describing GaN (gallium nitride) contains the comment ". , .p-type material does not seem achievable". The most recent reference in that same section is from 1980. In fact, throughout most of the book, the references are not more re- cent than 1990. Of course, most material parameters for semiconductors are not

DM 88.00, ISBN 3-540-60883-4.

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changing, but the quality of material is constantly improving; consequently some material parameters have been more accu- rately measured. Furthermore, the cover- age of 11-VI materials is very limited. Basic information such as energy gaps and lattice constants are included, but not much else. A final omission from the vol- ume is coverage of amorphous semi- conductors. The editor notes that this is in- tentional, but the inclusion of some of these materials would have been welcome, and would not increase the volume size significantly.

This book is extremely useful for the scientist who needs basic material param- eters for common semiconductors. It is particularly invaluable for anyone who needs information about group IV or 111-V semiconductors. However, for the scien- tist working with amorphous or 11-VI semiconductors - or the nitrides - this book falls short.

Mason Thomas Electrical and

Computer Engineering Department University of California at Santa Barbara

Santa Barbara, CA 93103 (USA)

Processing of Semiconductors. Edited by K . A. Jackson, Volume 16 of Materials Science and Technology - A Compre- hensive Treatment, edited by R. W. Cahn, P. Haasen, and E. J. Kramer, VCH, Weinheim 1996, XV, 689 pp., hardcover, DM 498.00, ISBN 3-527-

Today the processing of semiconduc- tors from the basic raw materials to the final packaged device is an important worldwide industry, which, for its success, requires the diverse skills of many scienti- fic disciplines. The scope of the topic is vast, beginning with the metallurgy of the large scale production of high purity ele- ments and leading to the fabrication of de- vices with submicrometer dimensions. It is hard, if not impossible, for anyone to be

an expert in all of the areas involved. However, it is important to maintain an up-to-date appreciation of the advances being made at each stage of the process, since breakthroughs in one area almost certainly impact on other areas, opening the way for new or improved device per- formance. For the materials scientist, and indeed for many other specialists, this book provides, in a single volume, a readi- ly accessible insight into the current state- of-the-art in semiconductor processing.

The stated objective of the series is that it should appeal to a broad readership, beyond that of materials scientists alone, and that it should be relevant and informa- tive to this readership. This volume clearly succeeds in meeting this objective.

The scope of the volume is extensive, covering silicon, the In-V compound semiconductors, and, to a much lesser ex- tent, the 11-VI compounds. In the case of silicon it begins with a chapter on the initi- al metallurgical processing from raw ma- terials (sand) through to the realization of high-purity substrates. This is followed by a similar review that presents and explains the added problems encountered in the processing of the compound semiconduc- tors to produce substrates. The next sec- tions deal with growth of epitaxial layers and the lithography and etching required as the building blocks of processing. These are considered in detail in terms of both of the basic principles of the processes involved and

looks at the increasingly important areas of packaging and interconnection technol- ogies. The chapters are written by authors who are respected scientists within their own field of expertise. All of the chapters have extensive references for more de- tailed reading on the topics covered.

This volume is well structured. It is up to date and should remain so for several years to come, since many of the trends identified by the authors will see semicon- ducting processing well into the next mil- lennium. The chapters are well written and are an excellent source of information on all aspects of the topic of semiconductor processing. The book is relevant to those who are active in the field of semiconduc- tor processing, those new to the area, and students studying the topic during their de- grees. The editors and indeed the authors have done an excellent job in putting to- gether a book that is easy to read and in- formative. It is written with the materials scientist in mind but is certainly of value to those who come from other scientific backgrounds. It is a book which can be highly recommended and which deserves to become a widely used reference work for those with a interest in semiconductor processing.

P. J. Wright DERA Malvern

St. Andrews Road Malvern, Worcs. WR14 3PS (UK)

the latest technological ad- vances that allow the realiza- tion of devices with sub- micrometer geometries. The next chapters cover device concepts, the complex device architecture, and the impor- tant questions relating to the trade-offs in processing that need to be considered to allow the high yields of ever more complex devices to be achieved. Finally the book

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