ABSTRACT: This thesis is about detection of cracks in single-crystalline silicon wafers by using a vibration method in the form of an impact test. The goal to detect cracks from vibration measurements introduced by striking the silicon wafer with an impact hammer. Such a method would reduce costs in the production of solar cells. It is an inexpensive, relatively simple method which if commercialized could be used as an efficient in-line production quality test. A hammer is used as the actuator and a microphone as the response sensor. A signal analyzer is used to collect the data and to compute frequency response. Parameters of interest are audible natural frequencies, peak magnitudes, damping ratio and coherence. The data reveals that there are differences in frequency between the cracked silicon wafers and the non-cracked silicon wafers. The resonant peaks in the defective wafers were not as sharp (i.e., lightly damped) and occurred at lower frequencies (i.e., lower stiffness) with a lower magnitude and a higher damping ratio. These differences could be used to detect damaged product in a solar cell production line.

Defects in silicon wafers affect their mechanical stability considerably during their processing and handling. In the new generation of thin silicon wafers, in addition to subsurface defects, cracks are also one of the most important defects that need to be evaluated. A comprehensive review of literature suggests the use of different techniques for non destructive evaluation (NDE) of silicon wafers. Among the few NDE techniques that can be used for both sub-surface and crack detection, Shearography has the advantage of being a whole field technique that can be utilized as a non-contact method for online inspection. Although, recently shearography has been used for sub-surface defect detection in silicon wafers, the capability of this technique to identify and detect cracks has not been investigated yet. In this work, a shearography system has been developed for nondestructive evaluation of silicon wafers. The optical set-up was arranged and several experiments were carried out to optimize its performance. Batch of perfect wafers, wafers with sub-surface defects and cracked wafers of 500?m thickness were qualitatively evaluated using the developed system. Two different loading mechanisms were used to stress the silicon wafer and the advantage of uniform thermal loading over concentrated force loading for crack and sub-surface defect detection has been discussed. In addition to crack detection, the unique potential of the developed system for detection of crack propagation has been discussed.

This book is intended to help satisfy an urgent requirement for up-to date comprehensive texts at graduate and senior undergraduate levels on the subjects in non-destructive testing (NDT). The subject matter here is confined to electrical and magnetic methods, with emphasis on the widely used eddy current and magnetic flux leakage methods (including particle inspection), but proper attention is paid to other techniques, such as microwave and AC field applications, which are rapidly growing in importance. Theoretical analyses relating to the various methods are discussed and the depths of presentation are often governed by whether or not the information is readily available elsewhere. Thus, for example, a considerable amount of space is devoted to eddy current theory at what the author considers to be a reasonable standard and not, as usually experienced, in either a too elementary manner or at a level appreciated only by a postgraduate theoretical physicist. The inclusion of the introductory chapter is intended to acquaint the reader with some of the philosophy of NDT and to compare, briefly, the relative performances of the more important methods of testing.

Ultra-thin chips are the "smart skin" of a conventional silicon chip. This book shows how very thin and flexible chips can be fabricated and used in many new applications in microelectronics, Microsystems, biomedical and other fields. It provides a comprehensive reference to the fabrication technology, post processing, characterization and the applications of ultra-thin chips.

CMP and polishing are the most precise processes used to finish the surfaces of mechanical and electronic or semiconductor components. Advances in CMP/Polishing Technologies for Manufacture of Electronic Devices presents the latest developments and technological innovations in the field - making cutting-edge R&D accessible to the wider engineering community. Most of the applications of these processes are kept as confidential as possible (proprietary information), and specific details are not seen in professional or technical journals and magazines. This book makes these processes and applications accessible to a wider industrial and academic audience. Building on the fundamentals of tribology - the science of friction, wear and lubrication - the authors explore the practical applications of CMP and polishing across various market sectors. Due to the high pace of development of the electronics and semiconductors industry, many of the presented processes and applications come from these industries. Demystifies scientific developments and technological innovations, opening them up for new applications and process improvements in the semiconductor industry and other areas of precision engineering Explores stock removal mechanisms in CMP and polishing, and the challenges involved in predicting the outcomes of abrasive processes in high-precision environments The authors bring together the latest innovations and research from the USA and Japan