This book is designed to introduce typical cleanroom processes, techniques, and their fundamental principles. It is written for the practicing scientist or engineer, with a focus on being able to transition the information from the book to the laboratory. Basic theory such as electromagnetics and electrochemistry is described in as much depth as necessary to understand and explain the current practice and their limitations. Examples from various areas of interest will be covered, such as the fabrication of photonic devices including photo detectors, waveguides, and optical coatings, which are not commonly found in other fabrication texts.