Atomic layer deposition of Y-stabilized ZrO2 for advanced DRAM capacitors

Bo Eun Park, Il Kwon Oh, Chandreswar Mahata, Chang Wan Lee, David Thompson, Han Bo Ram Lee, Wan Joo Maeng, Hyungjun Kim

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14 Citations (Scopus)

Abstract

With accelerated shrinking of integrated circuit, the fabrication of metal-insulator-metal (MIM) capacitors having a high capacitance density and low leakage current for dynamic random access memory (DRAM) has become a challenge. In this study, we investigated Y-stabilized ZrO2 as a novel high-k material for DRAM capacitors. We used atomic layer deposition (ALD) to produce Y-stabilized ZrO2; this technique enables easy control of the Y concentration by changing the ratio of ZrO2 to Y2O3 ALD cycles. This technique is suitable for future DRAM capacitors, as it provides superior thickness controllability and conformality. Y doping into ZrO2 increases the oxygen vacancy content in the films and transforms the ZrO2 crystal structure from monoclinic to cubic. As a result, the dielectric constant is significantly increased from 19.1 to 30.2. Moreover, Y doping shifts the defect level into the conduction band rather than the energy bandgap, resulting in about 60 times lower leakage current density for Y-doped ZrO2 compared to undoped ZrO2. It is notable that the dielectric properties and the leakage current density are simultaneously enhanced, indicating that Y-doped ZrO2 is a promising candidate to satisfy the requirements of future DRAM capacitors.

Original languageEnglish
Pages (from-to)307-312
Number of pages6
JournalJournal of Alloys and Compounds
Volume722
DOIs
Publication statusPublished - 2017 Jan 1

All Science Journal Classification (ASJC) codes

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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    Park, B. E., Oh, I. K., Mahata, C., Lee, C. W., Thompson, D., Lee, H. B. R., Maeng, W. J., & Kim, H. (2017). Atomic layer deposition of Y-stabilized ZrO2 for advanced DRAM capacitors. Journal of Alloys and Compounds, 722, 307-312. https://doi.org/10.1016/j.jallcom.2017.06.036