講演情報
[9a-PA2-3]Improved Energy Storage Characteristics of Antiferroelectric ZrO2 Capacitors with a Sub-Nanometer TiO2 Interfacial Layer
〇(D)JunKai Lai1, JinEn Lin1, ChiAn Ho1, JerChyi Wang1,2,3 (1.Chang Gung Univ. for Chang Gung University, 2.Chang Gung Memorial Hospital, 3.Ming Chi Univ. of Tech. for Ming Chi University of Technology)
キーワード：
Antiferroelectric、Oxygen Vacancies、Interfacial Layer
Antiferroelectric (AFE) ZrO2 thin films are promising for high energy storage density (ESD) due to their field-induced phase transition from the nonpolar tetragonal phase to the polar orthorhombic phase. However, ZrO2 capacitors with TiN electrodes often exhibit asymmetric polarization caused by oxygen-vacancy (Vo) formation at the ZrO2/TiN interface. In this work, a sub-nanometer TiO2 interfacial layer (IL) was inserted between a 10-nm ZrO2 film and the TiN top electrode to improve polarization symmetry and ESD. Devices with different TiO2 thicknesses were fabricated by ALD and crystallized by RTA. The incorporation of TiO2 significantly enhanced saturation polarization and symmetry, with the 18-cycle device showing the best performance. XPS O 1s analysis revealed that the TiO2 IL suppressed Vo generation by preventing oxygen loss from ZrO2, reducing the non-lattice oxygen fraction from 12.2% to 4.1%. Excessively thick TiO2 layers degraded polarization because of increased impedance. Furthermore, the optimized device exhibited the highest and most stable ESD over 106 cycles, demonstrating that a sub-nanometer TiO2 IL is an effective strategy for improving AFE ZrO2 capacitors for high-density energy storage applications.