Dresden 2014 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 96: Atomic Layer Deposition (DS jpointly with O)
O 96.6: Talk
Friday, April 4, 2014, 11:15–11:30, CHE 91
Atomic layer deposition of SrxTi1−xOy: Stoichiometry variation and layer characterization — •Solveig Rentrop1, Barbara Abendroth1, Hartmut Stöcker1, Ralph Strohmeyer1, Jura Rensberg2, Juliane Walter1, and Dirk C. Meyer1 — 1Institut für Experimentelle Physik, TU Bergakademie Freiberg — 2Institut für Festkörperphysik, Universität Jena
Resistance switching of metal-insulator-metal (MIM) capacitor structures is one of the possible routes for future non-volatile random access memories. A promising ternary dielectric for MIM devices is SrxTi1−xOy. In this material, the layer composition is found to determine dielectric and optical properties as well as the band gap.
Here, we present studies on the atomic layer deposition of amorphous SrTiO3 from Sr(iPr3Cp)2, Ti[N(CH3)2]4 and H2O at substrate temperatures of 300 ∘C and 320 ∘C, resp. By changing the Sr/Ti pulse ratio, we are able to tailor the stoichiometry from stoichiometric to Sr or Ti excess. The layer composition is obtained from X-ray fluorescence spectroscopy and Rutherford backscattering. The tuned band gap value is determined by using a Tauc plot of the ellipsometric absorption coefficient. Moreover, we investigated the dependencies of optical constants, layer density and surface morphology on the layer composition.
Carbon incorporated during deposition increases the leakage current. By X-ray photoelectron spectroscopy the carbon content was measured after Ar ion cluster sputtering. The results show that we are able to deposit carbon free SrxTi1−xOy layers for different Sr/Ti ratios.