Thin Solid Films, Vol.515, No.2, 493-495, 2006
Novel approach to growth of precipitate-free, high-quality oxide thin films suitable for device applications
To eliminate precipitates-segregates that can easily occur on the thin film surfaces of the multicomponent materials for electronics, a new approach is proposed, consisting of the following aspects: first, on the substrates, artificial steps of predefined height and width are produced, and second, films are grown on such substrates. The width of the step is taken equal to the 'double of the migration length' of the atomic species depositing on the substrate. In these conditions, precipitates migrate and gather at the step edges where the free energy is lowest and the resulting totally precipitate-free surface of the film on the step is suitable for device applications or integration purposes. The method has several other important advantages and they are discussed in the text. Using this new approach we present successful fabrication of a mesa structure showing intrinsic Josephson effect. We have used thin films of Bi-2212/Bi-2223 superstructure grown by MOCVD on (001) SrTiO3 single crystal substrates with artificial steps of about 20 mu m width. (c) 2006 Elsevier B.V. All rights reserved.
Keywords:precipitate-free;migration;multicomponent compounds;artificial step;oxide thin films;device