Impact of Nitrogen Incorporation on the Interface between Ge and La2O3or Y2O3Gate Dielectric: A Study on the Formation of Germanate

Zhi Xiang Cheng, Lu Liu, Jing Ping Xu, Yong Huang, Pui To Lai, Wing Man Tang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

5 Citations (Scopus)


La2O3and Y2O3are used as gate dielectric in Ge MOS capacitors, and their electrical and interfacial properties are comparatively studied. Due to the much higher reactivity of La2O3with Ge than Y2O3, thicker germanate interlayer is formed, leading to better interface quality for the former. Moreover, it is found that N incorporation in the oxides reduces the formation of both germanate and GeOx, with much more obvious effect for La2O3and thus the best interface quality (a low interface-state density of 4.96 × 1011cm-2eV-1), which gives promising electrical properties: large equivalent dielectric constant (18.8), small flat-band shift (0.37 V), low gate leakage current (2.89 × 10-4A/cm2at Vg= Vfb+ 1 V), and high reliability under electrical stress.
Original languageEnglish
Article number7725493
Pages (from-to)4888-4892
Number of pages5
JournalIEEE Transactions on Electron Devices
Issue number12
Publication statusPublished - 1 Dec 2016


  • Ge MOS
  • germanate
  • interface quality
  • nitrogen incorporation

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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