Many technologically important thin-film growth, processing and surface modification techniques employ low-energy (hyperthermal and keV) particles. Energetic particle sources include ion beams (for growth and sputter etching), cluster beams, pulsed laser beams and plasmas. Phenomenological evidence suggests that the use of these energetic particles can change growth modes and provide control of surface morphology and film properties. The key to improving this control is to better understand how the energetic beams influence film, surface properties and the microscopic mechanisms responsible for beam-induced effects. This book addresses growth, ion erosion, surface smoothing, texturing and pattern formation, etching, structural stabilization and stress relaxation. Materials modification from the nanoscale to the mesoscale and macroscale are discussed as well as technological applications including thin-film transistors, microelectronics, materials for X-ray mirrors, high-temperature superconductors, sensors and diamond-like coatings. Papers on modeling and analysis of these processes using techniques including molecular dynamic simulations are also included..