Dresden 2009 – wissenschaftliches Programm
DS 15.4: Vortrag
Dienstag, 24. März 2009, 16:15–16:30, GER 38
Piezoelectric phenomena in barium titanate thin films observed in nanoscale using piezoresponse force microscopy — •Grzegorz Wielgoszewski1, Teodor Gotszalk1, Piotr Firek2, Jan Szmidt2, and Aleksander Werbowy2 — 1Wrocław University of Technology, Faculty of Microsystem Electronics and Photonics, ul. Z. Janiszewskiego 11/17, PL-50372 Wrocław, Poland — 2Warsaw University of Technology, Institute of Microelectronics and Optoelectronics, ul. Koszykowa 75, PL-00662 Warszawa, Poland
Piezoelectric effect in the nanoscale, especially in single crystals of piezoelectric materials, is getting attention of microelectronics researchers very quickly. Thin films of ferroelectric materials (e.g. barium titanate) have a wide variety of application, e.g. high-density dynamic random access memories (DRAMs) or infrared detectors. In order to apply those materials in the most optimal way, one have to completely analyze and diagnose the piezoelectric effect in materials of various thickness and composition. One of the most expected result of the research is calculating the piezoelectric constant of the material.
To investigate such thin films in nanoscale, we constructed a piezoresponse force microscope (PFM). Applying ac voltage between the microtip of a PFM's probe and metal layer placed under the piezoelectric layer causes mechanical oscillation in the investigated film, which is measured using a lock-in amplifier.
We present the PFM construction and results of simultaneous measurements of the topography and piezoelectric response of the barium titanate layers, which thickness was less than 100 nm.