Permittivity enhancement of Al2O3/ZrO2 dielectrics with the incorporation of Pt nanoparticles

• Published in: Journal of applied physics 2024-09, Vol.136 (10)
• Main Authors: Zhu, Bao, Shang, Ze, Wang, Chenyan, Wu, Xiaohan, Zhang, David Wei
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Atomic layer epitaxy; Capacitance; CMOS; Density; Dielectric breakdown; Electric fields; Leakage current; Nanoparticles; Permittivity; Platinum; Thickness ratio; Zirconium dioxide
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/5.0218456

Al2O3/ZrO2 (A/Z) layers with embedded Pt nanoparticles (Pt-nps) at the interface of A/Z have been used to create a dielectric film with an enhanced permittivity. The Pt-nps and dielectrics are both grown by the atomic layer deposition process, which is complementary metal–oxide–semiconductor compatible. In order to control the thickness ratio of Pt-nps in the overall dielectrics more easily, the thickness of the ZrO2 layer is changed from 12 to 30 nm with a fixed thickness of 12 nm for Al2O3 and constant growth cycles of 70 for Pt-nps. The results show that the introduction of Pt-nps is beneficial to the enhancement of the dielectric permittivity. As the thickness of ZrO2 is 30 nm, the capacitance density increases from 2.5 to 5.1 fF/μm2 with the addition of Pt-nps, i.e., a doubling of the capacitance density achieved. Additionally, the leakage current at 2 V increases from 1.1 × 10−8 to 1.5 × 10−7 A/cm2. Furthermore, the dielectric breakdown field decreases from 5.4 to 2.7 MV/cm. The electric field distribution simulation and charging–discharging test imply that interfacial polarization is built at the interface of Pt-nps and the dielectric films, which contributes to the dielectric permittivity enhancement, and local electric field increasing in the affinity of Pt-nps gives rise to the deterioration of the leakage current and breakdown electric field.