| AVS 58th Annual International Symposium and Exhibition | |
| Thin Film Division | Monday Sessions |
| Session TF-MoM |
| Session: | Thin Films: Growth and Characterization I |
| Presenter: | Florian Stemme, Karlsruhe Institute of Technology (KIT), Germany |
| Authors: | F. Stemme, Karlsruhe Institute of Technology (KIT), Germany H. Gesswein, Karlsruhe Institute of Technology (KIT), Germany C. Azucena, Karlsruhe Institute of Technology (KIT), Germany M. Sazegar, Darmstadt University of Technology, Germany J.R. Binder, Karlsruhe Institute of Technology (KIT), Germany M. Bruns, Karlsruhe Institute of Technology (KIT), Germany |
| Correspondent: | Click to Email |
Barium strontium titanate (BST) is a very promising material for tunable microwave applications like phase-shifters and tuneable filters. Due to this the influence of e.g. annealing conditions and processes on thin film properties and their dielectric performance were largely investigated. But very few researchers have tried to change the sputtered BST thin film properties by using different dopants at the same time. Such iron and fluorine co-doped thin films can be achieved by RF magnetron sputtering, with a co-sputter target and a two step annealing process after deposition. The first annealing process provides the crystallinity of the films. In the second annealing process the fluorine co-dopant is introduced into the BST thin films by a diffusion controlled process.
The present contribution focuses on the processing and characterization of the iron doped BST thin films with various amounts of fluorine co-dopant. The characterization of the thin films by X-ray photoelectron spectroscopy (XPS) provides chemical binding states and film composition. XPS and time of flight secondary ion mass spectrometry (ToF SIMS) sputter depth profiles prove the chemical homogeneity and the film thickness. Grazing incident X-ray diffraction (XRD) and Raman spectroscopy validate the crystallinity and the identification of chemical phases. Furthermore film morphology is determined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Dielectric measurements, to investigate the influence of the donor and acceptor co-doping on the dielectric performance, were carried out in metal insulator metal (MIM) structures with ground signal ground probes.