skip to main content

Title: The role of ZrN capping layer deposited on ultra-thin high-k Zr-doped yttrium oxide for metal-gate metal–insulator–semiconductor applications

Metal-gate MIS structures with and without ZrN capping layer on high-k Y{sub 2}O{sub 3}:Zr/Y{sub 2}O{sub 3} stack were fabricated. The binding energies and depth profiles were investigated by x-ray photoelectron spectroscopy (XPS). The x-ray diffraction (XRD) patterns were compared. It is found that Ti out-diffusion into Zr-based high-k dielectric becomes lesser with the insertion of ZrN capping layer. The electrical properties of current-voltage (I-V) and capacitance-voltage (C-V) characteristics were measured in the postannealing temperature range of 550–850 °C. According to the defect reaction model, Zr cation vacancies are associated with the concentration of Ti ion by a transition from +3 to +2 states. The amount of Zr cation vacancies is quantified and equal to a half of Ti substitution amount at Zr site. The reduction in cation vacancies at high temperatures can well explain the decrease in ΔV{sub FB} for samples with ZrN layer. In contrast, an excess of Ti outdiffusion will produce the interstitial defects in high-k films without ZrN capping.
Authors:
; ;  [1]
  1. Department of Materials Engineering and Center for Thin Film Technologies and Applications, Ming Chi University of Technology, New Taipei City 243, Taiwan (China)
Publication Date:
OSTI Identifier:
22218102
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 8; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; BINDING ENERGY; CAPACITANCE; CATIONS; DIELECTRIC MATERIALS; DOPED MATERIALS; INTERSTITIALS; LAYERS; THIN FILMS; TITANIUM; TITANIUM IONS; VACANCIES; X-RAY DIFFRACTION; X-RAY PHOTOELECTRON SPECTROSCOPY; YTTRIUM OXIDES; ZIRCONIUM; ZIRCONIUM NITRIDES