Novel deuterated cyclopentadienyl zirconium/hafnium precursors for atomic layer deposition of high-performance ZrO2/HfO2 thin films

• Published in: Applied materials today 2024-10, Vol.40, p.102354, Article 102354
• Main Authors: Park, Sunwoo, Choi, Yoona, Park, Sangwook, Lee, Hayoon, Lee, Kiho, Kang, Seokwoo, Park, Jongwook, Jeon, Woojin
• Format: Article
• Language: English
• Subjects: Atomic layer depositions; Deuteriums; Hafnium oxides; Hafnium precursors; Zirconium oxides; Zirconium precursors
• ISSN: 2352-9407
• DOI: 10.1016/j.apmt.2024.102354

•New organometallic precursors were synthesized by introducing deuterium.•Deuteration simultaneously enhance thermal stability and reactivity of precursors.•Achieving high deposition temperature of 400 °C by deuterated precursors.•Enables suppressing defect formation and improvement in crystallinity.•Ultra-high-temperature resulted in excellent electrical properties in MIM capacitor. The need to improve the electrical properties of ZrO2 and HfO2 thin films deposited by atomic layer deposition (ALD), which is widely used in the field of microelectronics, is growing. Attempts to improve precursor stability unavoidably lead to reduced reactivity and diminished utility. Therefore, we synthesized and developed two new ALD precursors by introducing deuterium, which simultaneously exhibit enhanced thermal stability and enhanced reactivity as a result of the introduction of deuterium. For the substitution of deuterium for hydrogen in the precursors responsible for the enhanced thermal stability, we experimentally and theoretically demonstrated that thermal stability and reactivity can be simultaneously enhanced by reducing the bonding dissociation energy of ligands that have not undergone deuterium substitution. This observation led to the development of ZrO2 and HfO2 ALD processes that result in no impurities within the thin films and minimal substrate damage even at a very high deposition temperature of 400 °C. In particular, the improvement in crystallinity through ultra-high-temperature ALD deposition resulted in excellent electrical properties in a metal–insulator–metal capacitor in which the film was incorporated; the capacitor demonstrated a dielectric constant of 37.9 and leakage current of 3.52 × 10−9 A cm−2, without the need for a subsequent annealing process. [Display omitted]