According to Bernie Meyerson, IBM's chief technology of?cer, the traditional sc- ing of semiconductor manufacturing processes died somewhere between the 1- and 90-nanometer nodes. One of the prime reasons is the low dielectric constant of SiO - thechoice dielectricof all modern electronics. This book presents materials 2 fundamentals of the novel gate dielectrics that are being introduced into semic- ductor manufacturing to ensure the Moore's law scaling of CMOS devices. This is a very rapidly evolving?eld of research and we try to focus on the basicundersta- ing of structure, thermodynamics, and electronic properties of these materials that determine their performance in the device applications. Thevolume was conceivedin 2001 afteraSymposium on Alternative Gate - electrics we had at the American Physical Society March Meeting in Seattle, upon the suggestion of the Kluwer editor Sabine Freisem. After several discussions we decided that such a bookindeed would be useful as long as we could focus on the fundamental side of the problem and keep the level of the discussion accessible to graduate students andavariety of professionals from different ?elds. The problem of?nding a replacement for SiO asa gate dielectric bringstogether inaunique way 2 many fundamental disciplines. At the same time this problem is truly applied and practical. It looked unlikelythat the perfect new material would be foundfast; rather there would be a series of evolving candidate materialsand approaches.