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

Journal Article · Sun Nov 15 00:00:00 EST 2015 · AIP Advances

DOI:https://doi.org/10.1063/1.4935749· OSTI ID:22492180

Kumar, Arvind; Mondal, Sandip

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 density 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.

• OSTI ID: 22492180
• Journal Information: AIP Advances, Vol. 5, Issue 11; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
• Country of Publication: United States
• Language: English

Related Subjects

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