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Title: DLTS analysis of amphoteric interface defects in high-TiO{sub 2} MOS structures prepared by sol-gel spin-coating

High-κ TiO{sub 2} thin films have been fabricated from a facile, combined sol – gel spin – coating technique on p and n type silicon substrate. XRD and Raman studies headed the existence of anatase phase of TiO{sub 2} with a small grain size of 18 nm. The refractive index ‘n’ quantified from ellipsometry is 2.41. AFM studies suggest a high quality, pore free films with a fairly small surface roughness of 6 Å. The presence of Ti in its tetravalent state is confirmed by XPS analysis. The defect parameters observed at the interface of Si/TiO{sub 2} were studied by capacitance – voltage (C – V) and deep level transient spectroscopy (DLTS). The flat – band voltage (V{sub FB}) and the density of slow interface states estimated are – 0.9, – 0.44 V and 5.24×10{sup 10}, 1.03×10{sup 11} cm{sup −2}; for the NMOS and PMOS capacitors, respectively. The activation energies, interface state densities and capture cross – sections measured by DLTS are E{sub V} + 0.30, E{sub C} – 0.21 eV; 8.73×10{sup 11}, 6.41×10{sup 11} eV{sup −1} cm{sup −2} and 5.8×10{sup −23}, 8.11×10{sup −23} cm{sup 2} for the NMOS and PMOS structures, respectively. A low value of interface state densitymore » in both P- and N-MOS structures makes it a suitable alternate dielectric layer for CMOS applications. And also very low value of capture cross section for both the carriers due to the amphoteric nature of defect indicates that the traps are not aggressive recombination centers and possibly can not contribute to the device operation to a large extent.« less
Authors:
; ;  [1]
  1. Department of Physics, Indian Institute of Science, Bangalore, 560012 (India)
Publication Date:
OSTI Identifier:
22492180
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 5; Journal Issue: 11; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ACTIVATION ENERGY; ATOMIC FORCE MICROSCOPY; CAPACITANCE; DEEP LEVEL TRANSIENT SPECTROSCOPY; DIELECTRIC MATERIALS; ELLIPSOMETRY; GRAIN SIZE; INTERFACES; LAYERS; RECOMBINATION; REFRACTIVE INDEX; SILICON; SILICON OXIDES; SOL-GEL PROCESS; SPIN-ON COATING; SUBSTRATES; THIN FILMS; TITANIUM OXIDES; X-RAY DIFFRACTION; X-RAY PHOTOELECTRON SPECTROSCOPY