TY  - JOUR
AU  - Regnery, S.
AU  - Thomas, R.
AU  - Ehrhart, P.
AU  - Waser, R.
TI  - SrTa2O6 thin films for high-K dielectric applications grown by chemical vapor deposition on different substrates
JO  - Journal of applied physics
VL  - 97
SN  - 0021-8979
CY  - Melville, NY
PB  - American Institute of Physics
M1  - PreJuSER-47396
SP  - 073521
PY  - 2005
N1  - Record converted from VDB: 12.11.2012
AB  - SrTa2O6 thin films with thickness between 6 and 150 nm were deposited by metal-organic chemical vapor deposition in a multiwafer planetary reactor. The monomolecular precursor, strontium-tantalum-(methoxyethoxy)-ethoxide, was dissolved in toluene and injected by a liquid delivery system. A rather narrow process window for the deposition of stoichiometric SrTa2O6 was found for this precursor at low pressures and a susceptor temperature around 500 degrees C. Films were grown on Pt/TiO2/SiO2/Si, TiNx/Si, and SiO2/Si substrates. The as-deposited films were x-ray amorphous and could be crystallized by postannealing at a temperature >= 700 degrees C. The distorted tetragonal tungsten bronze phase of SrTa2O6 was dominating within a broad range of compositions (Sr/Ta: 0.4-0.7) and a perovskite-type phase was additionally observed for Sr/Ta>0.7 and predominated for Sr/Ta>1. The electrical properties have been investigated with metal-insulator-metal and metal-insulator-semiconductor capacitors after sputter deposition of Pt top electrodes. The amorphous films had a dielectric constant K in the range of 35-45 and low leakage currents. For stoichiometric SrTa2O6 the dielectric permittivity reached values of K=100-110, but the leakage currents were increased. Remarkably, the permittivity is not very sensitive to deviations from the exact stoichiometry of the SrTa2O6 phase (Sr/Ta: 0.4-0.7), but a decrease to values of K=30-40 is observed along with the transition to the perovskite phase at high Sr contents. (C) 2005 American Institute of Physics.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000228287300032
DO  - DOI:10.1063/1.1873033
UR  - https://juser.fz-juelich.de/record/47396
ER  -