Physics of Thin Films

Abstract

About five years ago when one wanted to become acquainted with thin film deposition techniques and the properties of thin films there were two standard books which covered the literature published on these subjects quite adequately. These books were written by Holland and Mayer. However, in the past few years the number of papers published annually on all aspects of films has increased tremendously and it is next to impossible for one author to keep abreast of all the new developments in this rapidly expanding field. Since it is likely that the research in this area which includes optical, electrical, magnetic, and superconducting properties as well as various surface reactions and surface phenomena, just to name a few, will grow at an even faster rate in the future, there was a definite need for up-to-date survey articles on important advances in this field.The first volume of the series "Physics of Thin Films" serves this purpose very well, indeed. Quite appropriately the first article by H. L. Caswell is on ultrahigh vacuum evaporators and residual gas analysis with emphasis on the importance of the vacuum in which films are deposited in determining their characteristics. The second article by

Fluorine-doped tin oxide films by spray pyrolysis using vacuum within nozzle

“…The carrier gas and precursor solution mixture and the size distribution of droplets are dependent significantly on the geometry of the nozzle (13) . The spray nozzle works by creating a vacuum inside the nozzle, absorbing the solution.…”

“…The spray pyrolysis involves a thermally stimulated chemical reaction between clusters of liquid/vapor atoms (13) . Thus to obtain the corresponding fluoride-doped tin oxide films an acidic solution of tin chloride and ammonium fluoride were sprayed on hot substrate (at 600 o C) with air as carrier gas.…”

“…FTO semiconductors have applications as transparent conductors, heat reflectors, oxide matrix in the dyesensitized solar cells (1,2,6) . For the preparation of FTO electrodes, the sol-gel method, chemical vapor deposition and spray pyrolysis techniques have been reported (10)(11)(12)(13)(14)(15) . Spray pyrolysis involves spraying a solution containing chemical species and a heated substrate (14,15) .…”

“…Spray pyrolysis involves spraying a solution containing chemical species and a heated substrate (14,15) . The heated substrate provides the thermal energy for thermal decomposition and subsequent recombination of the constituent species, and followed by sintering and recrystallization of the clusters of crystallites on substrate surface (7,13) . The spray pyrolysis of SnCl 4 solution for obtaining TCOs was performed as early as 1910 (13) .…”

Analysis of Residual Stress Gradient in MEMS Multi-layer Structure

“…In general, thermal stress th σ is uniform through the thickness and it can be calculated from [3] A free film-substrate system is referred to a rectangular coordinate system oriented as shown in Fig. 1.…”