ABSTRACT
An inherent consequence of the replacement of SiO2 and SiO x N y as the gate dielectrics in the future generations of CMOS devices is that a new method for the dielectric deposition will be needed too. Among the various candidates, atomic layer deposition (ALD, also known by the names atomic layer epitaxy (ALE) and atomic layer chemical vapour deposition (ALCVD), for example) offers certain important characteristics like excellent large area uniformity, outstanding conformality, and atomic level control of film composition and thickness [1–4]. As a consequence, ALD of high-κ oxides has been a subject of increasingly intense research during the past few years. On the other hand, while new in the gate oxide application, the ALD method has been examined and developed continuously since its introduction in the late 1970s [5–8]. Most importantly, in thin film electroluminescent (TFEL) display devices [1], which were the original motivation for developing ALD and remained the only industrial application of ALD for a long time, one uses insulator films that are required to have quite similar properties as the high-κ gate dielectrics. Therefore, ALD processes for many potential high-κ gate oxide materials were developed and characterized already before the current high-κ research began [1].
