SURFACE AND INTERFACE ANALYSIS, VOL. 20, 1081-1082 (1993)

Book Review

D. BRIGGS and M. SEAH (Eds) Practical Surface Analysis Volume 2. Ion and Neutral Spectroscopy Wiley, Chichester (1993) Price: E99. No. of pages: 756. ISBN: 471920827 The last two decades have witnessed a remarkable growth in the number of dif- ferent surface analytical techniques, re- sulting in a plethora of different acronyms. Of these techniques only a comparatively small number, mainly based on electron and ion spectroscopy, have become widely established in the field of practical materials surface analysis. Practical Surface Analysis, edited by Briggs and Seah, and first published in 1983 as volume 1, gave a comprehensive treatment of electron spectroscopies (AES and XPS) and ap- peared in a second, totally revised edi- tion in 1990. It has now been joined by a new (multi-author) volume 2, which covers surface analytical techniques based on ion and neutral spectroscopy and this is the volume reviewed here.

The original aim of the title was to provide a practically useful, detailed overview of the various aspects of the surface analytical techniques covered, including instrumentation, relevant theory, the status of quantification and applications, in particular for new en- trants to the field. The bulk of the material in Volume 2 (480 pages) is con- cerned with secondary ion mass spec- trometry (SIMS) both in its static and dynamic forms and sputtered neutral mass spectrometry (SNMS); low- and medium-energy ion scattering spectro- scopies are covered in close to 100 pages and a similar amount of space is taken up by appendices. Being a multi-author volume, the scope of the various chap- ters, depth of treatment of the subject and style are somewhat variable.

The volume opens with a perspective of surface and interface analysis by the editors, which paints an informative his- torical backcloth of the techniques dis- cussed. This is followed by a substantial chapter by Jede, Ganschow and Kaiser on SIMS instrument design. It discusses the various components of primary ion beam columns, beam scanning and sec- ondary ion extraction, quadrupole and magnetic sector mass spectrometers, microprobe and microscope design as well as time-of flight SIMS instruments and includes an assessment of the com- parative strengths of each design; in all, a good overview covering a broad field.

In Chapter 3, Wittmaack gives a clear and accomplished account of the rele- vant fundamentals of sputter depth pro- filing. The dependence of sputter yield on various parameters of the sputtering process are discussed, as are profile- broadening effects. For those familiar with the field it represents a concise summary; at the same time it will alert newcomers to the field to the complex dependence of, for example, the depth resolution on fundamental parameters and experimental conditions. One won- ders though why, in the context of the discussion of profile shift, a simple con- cept such as actual shift (due to the ac- cumulation of primary particles behind the feature of interest) does not get a mention in addition to apparent shift, which occurs due to transient sputter- ing. It is discussed later on in Chapter 5. Quantification in SIMS and SNMS is treated by Williams in Chapter 4 in a clear and informative way. After sur- veying the progress made in recent years in the theory describing the complex ionization processes, which has led to a degree of confidence in the use of ioniza- tion efficiency vs. ionization potential curves, he focuses on practical analytical strategies (e.g. various aspects of the use of bulk and implanted standards) and demonstrates the level of quantification that can be achieved. In the next chap- ter, Dowsett and Clark deal with the ap- plication of dynamic SIMS to depth profiling of electronic materials, the largest area of application of the tech- nique. It contains a wealth of informa- tion on practical approaches in the profiling of dopants/impurities and high concentrations, as well as shallow pro- tiling, and contains a detailed discussion on the sources of error in profiling and the definition of depth resolution. Their restatement of the meaning of the word ‘artefact’ can only be welcomed. The ap- plication of static SIMS for the analysis of surfaces is covered in Chapters 6 and 7, the first of which, by Reed and Vick- erman, deals with inorganic materials and the second, by Briggs, with organic materials. Inevitably there is some overlap/reinforcement of points in the methodology. Both chapters demon- strate that the crux for obtaining infor- mative SIMS spectra from an important class of materials such as insulators lies in the control of the surface potential through the use of electron beam charge compensation and/or atom beams. The question of whether sputtered clusters represent the surface structure is

.answered affirmatively by the experi- mental evidence presented and the capa- bilities of the technique are convincingly demonstrated in a whole range of well- rehearsed application studies, which illlustrate the progress made during the Mast decade; an impressive example is the low-dose imaging capability of the time-of-flight SIMS instrument with its parallel mass detection. In Chapter 8, ihe same trio who authored Chapter 2 give a rather lengthy account of the state of development of SNMS, the main at- traction of which is its potential of quantification by by-passing the matrix effect that bedevils SIMS. Different post-ionization methods and their in- strumentation are discussed and the chapter also contains a rather detailed discussion of relative sensitivity factors, on which quantification of the technique is based. The high depth resolution capability of SNMS is highlighted and the advantages and limitations of the technique are assessed. The final two chapters are concerned with ion scat- tering techniques. Niehus, in Chapter 9, gives a clearly written overview of low- energy ion scattering from its early ap- plication as a very surface sensitive compositional tool (ISS) to a highly sen- sitive surface (over)layer registry tool (ICISS), and in Chapter 10 Tromp pre- sents a concise and skilful survey of the field of medium-energy ion scattering (MEIS), illustrating its power for the analysis of surfaces, interfaces and thin films, especially in the quantitative determination of their crystallography. Elespite their conceptual simplicity, ion scattering techniques have largely re- mained a research instrument used in a comparatively small number of labor- atories and have thus, unlike SIMS, not become widely used, routine analytical tools. Yet the techniques are un- doubtedly practical and have resulted in a number of substantial and unique achievements in the area of surface crys- tallography and hence their inclusion in a volume of this title is fully justified.

The volume is concluded with four useful Appendices on subjects as diverse as electron-simulated desorption (as a talol for surface bonding orientation), the role of standards in SIMS, pure material sputter yield data and a very interesting chapter by Webb on com- puter simulation codes used for the simulation of implanted ion distribu- tions and sputtering. The latter gives an illuminating (albeit less-well-edited) overview of the variety of different tech-

1082 BOOK REVIEW

niques used in simulations and contains useful brief characterizations of the si- mulation codes discussed in the liter- ature.

In summary, this is a significant volume that presents a very readable overview of the state of ion and neutral spectroscopies in the early 1990s. Com-

plete with its fairly extensive index, it should be highly useful for both new- comers to the field of practical surface analysis wanting an introduction and for established workers as a reference work. I have found it very useful and am pleased to have it at hand. However, at .€90 the volume is expensive. Such a

price puts it practically outside the reach of most individual purchasers and in my experience even institution librar- ies initially baulk at this price level.

JAAP VAN DEN BERG Dept. of Electronic and Electrical

Engineering, University of Salford, Salford. UK