Investigation of structural and electrical properties of ▫$Al_2O_3/Al$▫ composites prepared by aerosol co-deposition

Regis de Moraes, Victor (author), Šadl, Matej (author), Brennecka, Geoff (author), Bradeško, Andraž (author), Tomc, Urban (author), Uršič Nemevšek, Hana (author)

As the microelectronic industry develops, components that can perform several different tasks receive increasingly more attention, resulting in multifunctional materials being highly sought after. ▫$Al_2O_3$▫ is widely present in electronic applications as a protective coating or as an electrical and thermal insulator due to its mechanical and thermal stabilities and chemical inertness. ▫$Al_2O_3$▫ is also an important dielectric material, with high resistivity and stable permittivity over a wide range of temperatures and electric fields, but its modest permittivity necessitates large effective areas or extremely thin layers when a large capacitance is desired. Composites consisting of discrete conducting phases within an insulating matrix can produce large capacitance via Maxwell–Wagner polarization. In this work, ▫$Al_2O_3$▫/Al composite thick films with different volume ratios of Al were prepared using the aerosol deposition method. A relative dielectric permittivity (εr′) of 800 at 1 MHz was achieved at 27 vol% of Al, a sixty-sevenfold enhancement compared to ▫$Al_2O_3$▫. On the other hand, dielectric losses, tan(δ), at 1 MHz increased from 0.01 for ▫$Al_2O_3$▫ up to 0.58 for the composite with 27 vol% of Al. A finite-element model of the composites was implemented, supporting the nonlinear electrical behavior of the composites as function of vol% of Al. Our results show novel possibilities for the applications of ▫$Al_2O_3$▫-based materials in the microelectronic industry, especially for temperature-sensitive applications, for which the integration strengths of aerosol deposition are valuable.

• Language: English
• Keywords: alumina, aluminum, multifunctional materials, thick films, aerosol deposition
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 12 str.
• Numbering: Vol. 13, iss. 5, art. 850
• PID: 20.500.12556/RUL-146160
• UDC: 620.1
• ISSN on article: 2073-4352
• DOI: 10.3390/cryst13050850
• COBISS.SI-ID: 152943619
• Publication date in RUL: 22.05.2023

Record is a part of a journal

• Title: Crystals
• Shortened title: Crystals
• Publisher: MDPI
• ISSN: 2073-4352
• COBISS.SI-ID: 36677893

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: alumina, aluminij, multifunkcijski materiali, debeli filmi, nanašanje z aerosolom