Wednesday, May 28, 2014

RWTH Aachen fabricate ferroelectric hafnium oxide by chemical solution deposition

RWTH Aachen fabricate ferroelectric hafnium oxide with a remnant polarization of >13 μC/cm2 by chemical solution deposition - to be specific - a yttrium-doped hafnium oxide films on platinum electrodes. This work opens up opportunities for applications using a thicker ferroelectric material than for ALD films at about 10nm that has been developed recent years by NaMLab and Fraunhofer IPMS-CNT.



Chemical solution deposition of ferroelectric yttrium-doped hafnium oxide films on platinum electrodes

S. Starschich, D. Griesche, T. Schneller, R. Waser and U. Böttger

Appl. Phys. Lett. 104, 202903 (2014): http://dx.doi.org/10.1063/1.4879283, Published online 21 Mai 2014

Abstract: Ferroelectric hafnium oxide films were fabricated by chemical solution deposition with a remnant polarization of >13 μC/cm2. The samples were prepared with 5.2 mol. % yttrium-doping and the thickness varied from 18 nm to 70 nm. The hafnium oxide layer was integrated into a metal-insulator-metal capacitor using platinum electrodes. Due to the processing procedure, no thickness dependence of the ferroelectric properties was observed. To confirm the ferroelectric nature of the deposited samples, polarization, capacitance, and piezoelectric displacement measurements were performed. However, no evidence of the orthorhombic phase was found which has been proposed to be the non-centrosymmetric, ferroelectric phase in HfO2.