Rare-earth oxide thin films as gate oxides in MOSFET transistors

In this paper, the possibilities of rare-earth oxides as gate dielectrics are discussed. The thin films have mostly been fabricated by physical vapor deposition methods. The rare earths most often studied are yttrium, lanthanum and gadolinium. The deposition of the gate oxide should be carried out under mild conditions, and therefore chemical deposition techniques are preferred. Atomic layer deposition of rare-earth oxides is introduced and special attention is given to the volatile precursors and deposition processes. The electrical properties of rare-earth oxide gate oxides will be highlighted. The results obtained are encouraging and the use of rare-earth oxides in gate stacks is possible. Especially, they may be important in connection to III-V compounds. (C) 2003 Elsevier Science (USA). All rights reserved.