This book focuses on foundry-based process techlogy that enables the fabrication of 3-D ICs. The core of the book discusses the techlogy platform for pre-packaging wafer lever 3-D ICs. However, this book does t include a detailed discussion of 3-D ICs design and 3-D packaging. This is an edited book based on chapters contributed by various experts in the field of wafer-level 3-D ICs process techlogy. They are from academia, research labs and industry.