Adhesion layer-bottom electrode interaction during BaxSr1-xTiO3 growth as a limiting factor for device performance

作者：Loffler Markus^*; Vorobiev Andrei; Zeng Lunjie; Gevorgian Spartak; Olsson Eva

来源：Journal of Applied Physics, 2012, 111(12): 124514.

DOI：10.1063/1.4730781

Changes in bottom electrode morphology and adhesion layer composition upon deposition of BaxSr1-xTiO3 (BSTO) at elevated temperatures have been found, which have a negative impact on acoustic wave resonator device performance. The difference between nominal and actual adhesion layer composition are explained by grain boundary diffusion of Ti or W and their oxidation by in-diffusing oxygen, which leads to an increased interface roughness between the Pt bottom electrode and the BSTO. It is shown, that room-temperature deposited TiO2 diffusion barriers fail to protect against Ti oxidation and diffusion. Also W adhesion layers are prone to this phenomenon, which limits their ability to act as high temperature resistant adhesion layers for bottom electrodes for ferroelectric thin films.

• 出版日期2012-6-15