Atomic layer deposition of Y 2 O 3 and yttrium-doped HfO 2 using a newly synthesized Y(iPrCp) 2 (N-iPr-amd) precursor for a high permittivity gate dielectric

Jae Seung Lee, Woo Hee Kim, Il Kwon Oh, Min Kyu Kim, Gyeongho Lee, Chang Wan Lee, Jusang Park, Clement Lansalot-Matras, Wontae Noh, Hyungjun Kim

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42 Citations (Scopus)

Abstract

We systematically investigated the effects of Y doping in HfO 2 dielectric layer, focusing on structural phase transformation and the dielectric properties of the resultant films. Y doping was carried out using atomic layer deposition (ALD) with a novel Y(iPrCp)2(N-iPr-amd) precursor, which exhibits good thermal stability without any decomposition and clean evaporation. As a result, the ALD process of the Y 2 O 3 films showed well-saturated and linear growth characteristics of ∼0.45 Å/cycle without significant incubation delays and produced pure Y 2 O 3 films. Then, yttrium-doped HfO 2 films with various Y/(Y + Hf) compositions (yttrium content: 0.6- 4.8 mol%) were prepared by alternating Y 2 O 3 and HfO 2 growth cycles. Structural and electrical characterization revealed that the addition of yttrium to HfO 2 induced phase transformations from the monoclinic to the cubic or tetragonal phases, even at low post-annealing temperatures of 600 C, and improved leakage current densities by inducing oxygen vacancy-related complex defects. A maximum relative dielectric constant of ∼33.4 was obtained for films with a yttrium content of ∼1.2 mol%. Excellent EOT scalability was observed down to ∼1 nm without dielectric constant degradation.

Original languageEnglish
Pages (from-to)16-21
Number of pages6
JournalApplied Surface Science
Volume297
DOIs
Publication statusPublished - 2014 Apr 1

Bibliographical note

Funding Information:
This work was supported by the Industrial Strategic Technology Development Program (1004192610041926, Development of high density plasma technologies for thin film deposition of nanoscale semiconductors and flexible display processing) funded by the Ministry of Knowledge Economy (MKE, Korea), and supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (2011-0028594).

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Condensed Matter Physics
  • Physics and Astronomy(all)
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films

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