Achieving High Dielectric Constants in Tetragonal Single‐Phase ZrHfO2 Thin Films through the Atomic Layer Deposition Process Using a Mixed Precursor. Issue 11 (12th April 2022)

• Record Type: Journal Article
• Authors: Kim, Jenam; Ryu, Young Uk; Lee, Ae Jin; Kim, Ye Won; Hwang, Ji Hyeon; Kim, Youngjin; Oh, Hansol; Park, YongJoo; Jeon, Woojin
• Is Part Of: Physica status solidi. Volume 219:Issue 11(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-12
• Subjects: atomic layer deposition -- hafnium oxide -- homogeneous thin film -- insulator -- mixed precursor -- zirconium oxide; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.202100652
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : Herein, the deposition of homogeneous Zr x Hf(1− x ) O2 ( x < 1) thin films for dynamic random‐access memory (DRAM) capacitor dielectric layers by atomic layer deposition (ALD) using a mixed precursor mixture of two precursors is investigated. ZrO2 ‐ and HfO2 ‐based thin films are widely used as capacitor dielectric layers because of their high dielectric constant ( k ) values and low leakage current properties. Herein, particularly, films with mixed structures of ZrO2 /HfO2 are investigated because ZrO2 supports the growth of HfO2 in the tetragonal phase. However, the mixed structures deposited by ALD remain inhomogeneous even after the annealing process. The inhomogeneity results in part of the HfO2 remaining in the monoclinic phase, which reduces the k value. Herein, the formation of homogeneous tetragonal‐phase Zr x Hf1− x O2 using a mixed precursor consisting of CpZr and CpHf precursors is investigated. The formation of the tetragonal phase in the Zr x Hf(1− x ) O2 thin films is determined through chemical and structural analysis. The variation of the electrical properties with the Zr/Hf concentration ratio is investigated. The electrical properties are enhanced compared to laminated ZrO2 /HfO2 and single thin films. Abstract : Herein, the dielectric constant of 53.7 of HfO2 in ZrHfO2 is achieved by the phase modulation of monoclinic phase formation suppression by employing the mixed precursor atomic layer deposition process. The leakage current property depending on Zr/Hf ratio in the ZrHfO2 thin film is investigated. Eventually, high‐performance ZrO2 and HfO2 ‐based high‐k thin film for the dynamic random access memory (DRAM) capacitor application is demonstrated.