Impact of interfacial layer using ultra-thin SiO₂ on electrical and structural characteristics of Gd₂O₃ MOS capacitor
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Date
2018-08-08
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Publisher
Springer
Abstract
The aim of present study is to improve the quality of Gd₂O₃/p-Si MOS structure by reducing interface trap charge density. Therefore, the ultra-thin SiO₂ layer was grown to high-k/Si interface. The effect of the post deposition annealing on the structural properties of the Gd₂O₃/SiO₂ films and electrical characteristics of the Al/Gd₂O₃/SiO₂/p-Si/Al were investigated for three different temperature. Besides, the effect of the series resistance and measurement frequency on the electrical characteristics of the p-MOS capacitors was examined in detail. 118 nm-thick Gd₂O₃ films were grown by RF magnetron sputtering following the 5 nm-thick SiO₂ deposition on p type Si wafer by dry oxidation method. While the Gd₂O₃ monoclinic characteristic peaks were observed in the Gd₂O₃/SiO₂/Si structures annealed at 600 A degrees C and 800 A degrees C, the XRD spectra of as-deposited and annealed at 400 A degrees C sample pointed out Gd silicate formation. -Si, -O, -Gd, and -H bonds were defined in the FTIR spectra of all samples. The frequency dependent capacitance-voltage (C-V) and conductance-voltage (G/omega-V) characteristics of Gd₂O₃/SiO₂ MOS capacitor were measured. Strong accumulation capacitance values in these devices did not change significantly depending on frequency. Unlike from the MOS capacitor with as-deposited and annealed Gd₂O₃/SiO₂ at 400 A degrees C, the interface trap charge density increased with increasing voltage frequency for the samples annealed at 600 A degrees C and 800 A degrees C. No significant change in the border trap density with increasing frequency was observed in the MOS capacitor except for as-deposited device. The barrier height increased with increasing frequency for all Gd₂O₃/SiO₂ MOS capacitors.
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Keywords
Engineering, Materials science, Physics, Rare-earth-oxides, Photoluminescence properties, Annelealing temperature, Gate dielectrics, Silicon, Deposition, Frequency, States, Devices, Films, Annealing, Capacitance, Capacitors, Dielectric devices, Electric resistance, Fourier transform infrared spectroscopy, Gadolinium compounds, Magnetron sputtering, Silica, Silicates, Silicon wafers, Characteristic peaks, Electrical characteristic, Frequency-dependent capacitance, Interface trap charge, Measurement frequency, Post deposition annealing, Rf-Magnetron sputtering, Structural characteristics, MOS capacitors
Citation
Kahraman, A. vd. (2018). ''Impact of interfacial layer using ultra-thin SiO₂ on electrical and structural characteristics of Gd₂O₃ MOS capacitor''. Journal of Materials Science: Materials in Electronics, 29(20), 17473-17482.