Physics of Thin Films: Advances in Research and Development primarily deals with the influence of ions or optical energy on the deposition, properties, and etching on thin films. The book is a collection of five articles, with one article per chapter. Chapter 1 covers ionized cluster beam deposition; epitaxy; and film-formation mechanism. Chapter 2 discusses the activated reactive evaporation process; the deposition of refractory compounds; the role of plasma in the process; and its applications. Chapter 3 focuses on ion-beam processing of optical thin films; ion sources and ion-surface interactions; and the different kinds of bombardment involved. Chapter 4 deals with laser induced etching - its mechanisms, methods, and applications. Chapter 5 talks about contacts to GaAs devices; Fermi-level pinning; and heterojunction contacts. The book is recommended for physicists and engineers in the field of electronics who would like to know more about thin films and the progresses in the field.