Cerium dioxide (CeO2) has many advantageous properties for various applications; such as high dielectric constant, chemical stability, transmission in the visible and infrared regions and high efficient ultra-violet absorption. For applications to silicon technology, epitaxial growth of CeO2 thin films on Si substrates has been studied, where a great deal of effort
has been devoted to make use of close epitaxial relations of CeO2 with silicon: both materials have cubic symmetry and a lattice parameter mismatch between them is only 0.35%. We are studying the epitaxial growth of very thin CeO2 layers on Si(100) substrates using reactive dc magnetron sputtering enhanced with an inductively coupled rf plasma. It has been found that the epitaxial CeO2 layer with (100) or (110) orientation is selectively grown by
controlling substrate bias and dc plasma power.
This paper demonstrates the first experimental results showing that low energy electron beam irradiation during reactive sputtering enables growth of CeO2(100)/Si(100). It is experimentally confirmed that there are two electron energies of ~35 and ~90 eV, which are effective in growing CeO2(100) layers. These features are explained in conjunction with ionization cross-section data of electrons in Ar ambient. This electron beam induced orientation selective epitaxial growth is very promising to develop into new technology of 2 dimensional patterning of different orientation regions; CeO2(100) and CeO2(110). Various applications will become possible, such as getting selectively orientation controlled overlayers. Details on the growth parameters for the growth of CeO2(100) layers will be given in terms of electron beam energy, dc plasma power and the growth rate, including crystallinity analyses by XRD and TEM. |