Water assisted atomic layer deposition of yttrium oxide using tris(N,N0-diisopropyl-2-dimethylamido-guanidinato) yttrium(III): Process development, film characterization and functional properties

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Lukas Mai - , Ruhr University Bochum (Author)
  • Nils Boysen - , Ruhr University Bochum (Author)
  • Ersoy Subaşı - , Ruhr University Bochum, Paderborn University (Author)
  • Teresa De Los Arcos - (Author)
  • Detlef Rogalla - , Ruhr University Bochum (Author)
  • Guido Grundmeier - , Paderborn University (Author)
  • Claudia Bock - , Ruhr University Bochum, Fudan University (Author)
  • Hong Liang Lu - , Fudan University (Author)
  • Anjana Devi - , Ruhr University Bochum (Author)

Abstract

We report a new atomic layer deposition (ALD) process for yttrium oxide (Y2O3) thin films using tris(N,N0-diisopropyl-2-dimethylamido-guanidinato) yttrium(III) [Y(DPDMG)3] which possesses an optimal reactivity towards water that enabled the growth of high quality thin films. Saturative behavior of the precursor and a constant growth rate of 1.1 Å per cycle confirm the characteristic self-limiting ALD growth in a temperature range from 175 C to 250 C. The polycrystalline films in the cubic phase are uniform and smooth with a root mean squared (RMS) roughness of 0.55 nm, while the O/Y ratio of 2.0 reveal oxygen rich layers with low carbon contaminations of around 2 at%. Optical properties determined via UV/Vis measurements revealed the direct optical band gap of 5.56 eV. The valuable intrinsic properties such as a high dielectric constant make Y2O3 a promising candidate in microelectronic applications. Thus the electrical characteristics of the ALD grown layers embedded in a metal insulator semiconductor (MIS) capacitor structure were determined which resulted in a dielectric permittivity of 11, low leakage current density (z107 A cm2 at 2 MV cm1) and high electrical breakdown fields (4.0–7.5 MV cm1). These promising results demonstrate the potential of the new and simple Y2O3 ALD process for gate oxide applications.

Details

Original languageEnglish
Pages (from-to)4987-4994
Number of pages8
JournalRSC advances
Volume8
Issue number9
Publication statusPublished - 2018
Peer-reviewedYes
Externally publishedYes

Keywords