High-voltage metal-insulator-metal capacitor based on crystalline HfAlO x film grown by atomic layer deposition

• Published in: Journal of vacuum science and technology. B, Nanotechnology & microelectronics Nanotechnology & microelectronics, 2019-01, Vol.37 (1)
• Main Authors: Lisiansky, Michael, Popov, Inna, Uvarov, Vladimir, Korchnoy, Valentina, Meyler, Boris, Yofis, Svetlana, Shneider, Yacov
• Format: Article
• Language: English
• ISSN: 2166-2746; 2166-2754
• DOI: 10.1116/1.5054848

A metal–insulator–metal (MIM) capacitor was developed herein with an atomic layer deposition-fabricated hafnia aluminate (HfAlOx) dielectric layer. A preparation flow combining pre- and post-deposition treatment yielded a device with increased capacitance density and excellent dielectric integrity that can be employed in front-end and back-end of line implementations. With an equivalent oxide thickness scalable to 2 nm and beyond, the MIM capacitor can be implemented in either RF or analog/mixed applications with a functional voltage up to 3.3 V as a decoupling element, or for memory, bypass and coupling needs. Reduction of the equivalent oxide thickness was achieved by engineering the phase composition of the dielectric layer. A k-value of ∼30 was obtained via intentional crystallization of HfAlOx into a high-symmetry phase. The role of the bottom electrode (TiN) predeposition treatment in the dielectric layer crystallization process and, consequently, in the electrical performance of the MIM capacitor is emphasized.