In semiconductor-device fabrication processes, lithography technology is used to print circuit patterns on semiconductor wafers. The remarkable miniaturization of semiconductor devices has been made possible only because of the continuous progress in lithography technology. However, for the trend of ever-increasing miniaturization to continue, a breakthrough in lithography technology is now needed. This book describes advanced techniques under development that represent the key to future semiconductor-device fabrication. To help the reader understand the background to developments in lithography technology, trends in ULSI technology and future prospects are reviewed, and the requirements that future lithography technology must meet are described. Several important lithography methods, such as deep UV lithography, x-ray lithography, electron-beam lithography, and focused ion-beam lithography are described in detail by experts in each area. Other relevant technologies, such as those that concern resist materials, metrology, and defect inspection and repair are also described.