Wafer Level 3-D ICs Process Technology focuses on foundry-based process technology that enables the fabrication of 3-D ICs. The core of the book discusses alternative technology platforms for pre-packaging wafer level 3-D ICs, with an emphasis on wafer-to-wafer stacking. Driven by the need for improved performance, a number of companies, consortia and universities are researching methods to use short, monolithically-fabricated, vertical interconnections to replace the long interconnects found in 2-D ICs. Stacking disparate technologies to provide various combinations of densely-packed functions, such as logic, memory, MEMS, displays, RF, mixed-signal, sensors, and power delivery is potentially possible with 3-D heterogeneous integration, making this technology the "Holy Grail" of system integration. Wafer Level 3-D ICs Process Technology is an edited book based on chapters contributed by various experts in the fields of wafer-level 3-D ICs process technology and applications enabled by 3-D integration.