High-κ Hf0.3Zr0.7O2 film with morphotropic phase boundary for DRAM capacitor by controlling H2O dose

• Published in: Applied surface science 2023-11, Vol.638, p.158078, Article 158078
• Main Authors: Du, Xin-Zhe, Luo, Zhen, Shen, Sheng-Chun, Bai, Wei-Ping, Gan, Hui, Yin, Yue-Wei, Li, Xiao-Guang
• Format: Article
• Language: English
• Subjects: DRAM capacitor; H2O dose; Hf0.3Zr0.7O2; High dielectric constant; Morphotropic phase boundary
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2023.158078

[Display omitted] •Morphotropic phase boundary of HZO film with high-κ is achieved by tuning H2O dose.•Leakage current is reduced by inserting an Al2O3 interfacial layer.•Good endurance against write/read cycles and high temperatures is realized. For the miniaturization of dynamic random-access memory (DRAM), it is necessary to obtain low equivalent oxide thickness (EOT) and low leakage capacitor materials with complementary metal-oxide semiconductor (CMOS) process compatibility. Herein, we explore the influence of the dose of H2O reactants on the phase structure and electrical characteristics of Hf0.3Zr0.7O2 (HZO) thin films during the atomic layer deposition (ALD). By controlling the H2O dose as well as other conditions including inserting alumina, adjusting annealing temperature and electric field cycling, a high dielectric constant of ∼45 (EOT ∼ 0.54 nm) and low leakage current density (1012 cycles (even extrapolated to 1015 cycles under voltage pulse of 0.5 V @10 MHz) at both room temperature and 85 °C. These results are helpful for achieving a high dielectric constant and low leakage for future generation DRAM capacitor materials.