Optical Diagnostics for Thin Film Processing

Abstract

In the last few years the thin film processing technologies have improved strongly, both from the point of view of the fundamental physics and from the point of view of applications. Thin film processing technologies include (i) material growth for electronic applications, such as semiconductors, insulators, metals, superconductors etc., (ii) material growth for mechanical applications such as protective super-hard and antiabrasive coatings, (iii) material growth for optical applications, (iv) material processing for lithography, patterning and etching and (v) device fabrication in microelectronics. In order to be able to increase the performances of materials and to increase the complexity of device processing it is necessary to understand the physics and chemistry of film processing and to reach a higher control of processing parameters. In-situ real time diagnostics are the most promising methods for this purpose. This book can be included into this framework. The book gives an interesting and detailed review of many optical diagnostics applied to thin film processing science and technology. The initial chapters report the background on thin film technologies (including a review of the different types of reactor and growth-processing technologies), properties of light, structure of matter and light - matter interaction in order to help readers not familiar with film processing technologies and spectroscopies. The other chapters are devoted to a deep analysis of optical diagnostics to be applied in-situ and in real time for the study of film, substrate or process gas physical properties. A wide range of optical techniques are reported: transmittance and reflectance spectroscopies, optical emission spectroscopy, laser spectroscopies, interferometry, scattering spectroscopies (elastic and inelastic), luminescence, optical thermometry and metrology. For all the techniques the author describes (i) the underlying physical and chemical principles, (ii) the experimental set-up for in-situ characterizations of thin films under processing or of process gas in the reactors and (iii) a survey of the applications of the diagnostics in thin film processing technology with the relevant spectroscopic data. A wide bibliography is given in all the chapters to allow the readers to be introduced to the physical and technological details of all the spectroscopic techniques described. Moreover, a wide review of applications of optical spectroscopies to thin film processing and gas diagnostic is successfully reported. The scope of the book, which is completely fulfilled, is to delineate the role of optical diagnostics in controlling and developing thin film processing techniques, through an in-situ and real time monitoring of the film, substrate or process gas properties. The presentation of the subject is clear, the book is well organized and the technical content is very high, so as to be useful also to scientists and engineers not familiar with thin film technologies or spectroscopic techniques. For people already expert in the subject the book will be an useful handbook. Moreover, there is a lack in scientific literature of a book or a review completely devoted to in-situ optical diagnostics of thin film technologies. The book could be addressed to researchers and engineers working on plasma processes, thin film growth, surface material processing or microelectronics.