Rare-earth-oxide ultrathin films

Increasing speed of development in microelectronics as well as in catalysis leads to the need of high performance thinfilm materials e.g. as gate-oxides in MOSFETs, new OLED applications or thinfilm coatings on catalysts. Especially in semiconductor industries the miniaturization of the microelectronic components requires new materials having higher dielectric constants and larger band gaps than conventionally used SiO2 as gate-oxide to avoid quantummechanical tunneling with concomitant high leakage and high heat diffusion rates. Conventionally used methods for thinfilm deposition (e.g. PVD, CVD) suffer from problems such as carbon impurities within the deposited layers and formation of interfacial layers. Rare-earth oxides are potential candidates to replace SiO2 as gate-oxide due to their electrical properties. Alternatively they are good candidates for OLED applications due to their luminescence. A radically new approach using new rare-earth based inorganic designer precursors which may easily be realized and incorporated into device production will be presented. In and ex UHV-Experiments have been done to study the constitution of the thin films, the crystallization process and the decomposition mechanism of the precursors on the surface using XPS, STM, AFM, SEM, TPD, TGA and TEM analyses. The precursors are expected to decompose carbonfree to form the oxide and gaseous decomposition products.