Improved Charge-Trapping Performance of Hf-Doped SrTiO3 for Nonvolatile Memory Applications

The charge-trapping characteristics of Hf doped SrTiO3 have been studied based on Al/Al2O3/Hf-doped SrTiO3/SiO2/Si capacitors. The thermodynamic stability of the SrTiO3 film is significantly improved by Hf incorporation, thus resulting in negligible formation of an interlayer at the Hf-doped SrTiO3/SiO2 interface, as confirmed by X-ray photoelectron spectroscopy and transmission electron microscopy. The memory device with Hf-doped SrTiO3 as charge-trapping layer displays high speed at low operating voltage (a VFB shift of 1.9 V at +6 V, 100 ms) and good data retention (charge loss of 12.7% after 104 s). Therefore, the Hf-doped SrTiO3 film is a promising material as charge-trapping layer for high-performance nonvolatile memory applications.postprin

Nitrided La 2O 3 as charge-trapping layer for nonvolatile memory applications

Charge-trapping characteristics of La 2O 3 with and without nitrogen incorporation were investigated based on Al/Al 2O 3/La 2O 3/SiO 2Si (MONOS) capacitors. The physical properties of the high-k films were analyzed by X-ray diffraction and X-ray photoelectron spectroscopy. Compared with the MONOS capacitor with La 2O 3 as charge-trapping layer, the one with nitrided La 2O 3 showed a larger memory window (4.9 V at ±10-V sweeping voltage), higher program speed (4.9 V at 1-ms +14 V), and smaller charge loss (27% after 10 years), due to the nitrided La 2O 3 film exhibiting less crystallized structure and high trap density induced by nitrogen incorporation, and suppressed leakage by nitrogen passivation. © 2012 IEEE.published_or_final_versio

Charge-Trapping Characteristics of Fluorinated Thin ZrO2 Film for Nonvolatile Memory Applications

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Effects of thermal annealing on La2O3 gate dielectric of InGaZnO thin-film transistor

The effects of thermal annealing on La2O3 gate dielectric of InGaZnO thin-film transistor (TFT) are investigated by varying annealing temperature. Due to densification and enhanced moisture resistance of the La2O3 film, its surface roughness and interface with InGaZnO are improved by the thermal annealing, thus leading to significant improvement in the TFT electrical performance. However, higher-temperature (450 oC) annealing deteriorates the dielectric roughness and induces more traps associated with grain boundaries in the La2O3 film. The TFT with an appropriate annealing (350 oC) shows the best performance with smallest sub-threshold swing (0.276 V/dec), lowest threshold voltage (3.01 V), highest field-effect mobility (23.2 cm2/V.s) and largest on-off current ratio (3.52×108). © 2015 The Electrochemical Society.postprin

Effects of fluorine incorporation on the electrical properties of silicon MOS capacitor with La2O3 gate dielectric

In this work, the effects of fluorine incorporation by using plasma on the electrical properties of Si MOS capacitor with La2O3 gate dielectric are investigated. From the capacitance-voltage (C-V) curve and gate leakage current, it is demonstrated that the F-plasma treatment can effectively suppress the growth of interfacial layer, and thus improve the electrical properties of the device in terms of accumulation capacitance, interface-state density and breakdown voltage. © 2011 IEEE.published_or_final_versio

LaTiON/LaON as band-engineered charge-trapping layer for nonvolatile memory applications

Charge-trapping characteristics of stacked LaTiON/LaON film were investigated based on Al/Al 2O 3/LaTiON-LaON/SiO 2/Si (band-engineered MONOS) capacitors. The physical properties of the high-k films were analyzed by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. The band profile of this band-engineered MONOS device was characterized by investigating the current-conduction mechanism. By adopting stacked LaTiON/LaON film instead of LaON film as charge-trapping layer, improved electrical properties can be achieved in terms of larger memory window (5.4 V at ±10-V sweeping voltage), higher program speed with lower operating gate voltage (2.1 V at 100-μs +6 V), and smaller charge loss rate at 125 °C, mainly due to the variable tunneling path of charge carriers under program/erase and retention modes (realized by the band-engineered charge-trapping layer), high trap density of LaTiON, and large barrier height at LaTiON/SiO 2 (2.3 eV). © 2012 The Author(s).published_or_final_versionSpringer Open Choice, 28 May 201

Improved performance of yttrium-doped Al 2O 3 as inter-poly dielectric for flash-memory applications

Yttrium-doped Al 2O 3Y xAl yO) with different yttrium contents prepared by co-sputtering method is investigated as the inter-poly dielectric (IPD) for flash memory applications. A poor SiO 2-like interlayer formed at the IPD/Si interface is confirmed by X-ray photoelectron spectroscopy, and can be suppressed by Y doping through the transformation of silica into silicate. Compared with Al 2O 3 and Y 2O 3 films, the optimized Y xAl yO film shows lower interface-state density, lower bulk charge-trapping density, higher dielectric constant, and smaller gate leakage, due to the suppressed interlayer and good thermal property ascribed to appropriate Y and Al contents in the film. Therefore, the optimized Y xAl yO film is a promising candidate as the IPD for flash memory. © 2010 IEEE.published_or_final_versio

Nitrided SrTiO 3 as charge-trapping layer for nonvolatile memory applications

Charge-trapping characteristics of SrTiO 3 with and without nitrogen incorporation were investigated based on Al/ Al 2 O 3/SrTiO 3/SiO 2 /Si (MONOS) capacitors. A Ti-silicate interlayer at the SrTiO 3/SiO 2 interface was confirmed by x-ray photoelectron spectroscopy and transmission electron microscopy. Compared with the MONOS capacitor with SrTiO 3 as charge-trapping layer (CTL), the one with nitrided SrTiO 3 showed a larger memory window (8.4 V at ±10 V sweeping voltage), higher P/E speeds (1.8 V at 1 ms +8 V) and better retention properties (charge loss of 38% after 10 4s), due to the nitrided SrTiO 3 film exhibiting higher dielectric constant, higher deep-level traps induced by nitrogen incorporation, and suppressed formation of Ti silicate between the CTL and SiO 2 by nitrogen passivation. © 2011 American Institute of Physics.published_or_final_versio

Improved charge-trapping properties of HfYON film for nonvolatile memory applications in comparison with HfON and Y 2O 3 films

The charge-trapping properties of HfYON film are investigated by using the Al/HfYON/SiO 2/Si structure. The physical features of this film were explored by transmission electron microscopy and x-ray photoelectron spectroscopy. The proposed device shows better charge-trapping characteristics than samples with HfON or Y 2O 3 as the charge-trapping layer due to its higher trapping efficiency, as confirmed by extracting their charge-trap centroid and charge-trap density. Moreover, the Al/Al 2O 3/HfYON/SiO 2/Si structure shows high program speed (4.5 V at 14 V, 1 ms), large memory window (6.0 V at 14 V, 1 s), and good retention property, further demonstrating that HfYON is a promising candidate as the charge-trapping layer for nonvolatile memory applications. © 2011 American Institute of Physics.published_or_final_versio

Charge-Trapping Characteristics of BaTiO3 with and without Nitridation for Nonvolatile Memory Applications

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