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Deposition of HfTiO x gate dielectric films on n-type Si and quartz substrates by sol–gel technique has been performed and the optical, electrical characteristics of the as-deposited HfTiO x thin films as a function of baking temperature have been investigated. The components and optical properties of HfTiO x thin films related to baking temperature are investigated by energy dispersive spectrometer (EDS), ultraviolet–visible spectroscopy (UV–Vis), and spectroscopy ellipsometry (SE). By measurement of EDS, the Hf/Ti molar ratio of HfTiO x thin films is calculated to be about 1:1.20 at all baking temperature. The increase in band gap is observed with the increase of baking temperature. Additionally, the electrical properties based on Al/Si/HfTiO x /Al capacitor are analyzed by means of the high frequency capacitance-voltage ( C-V ) and the leakage current density-voltage ( J-V ) characteristics. Results have shown that 200 °C-baked sample demonstrates good electrical performance, including larger dielectric constant of 23.31 and lower leakage current density of 5.12 × 10 −5 A/cm 2 at the gate voltage of 1 V. Additionally, the leakage current conduction mechanisms as functions of baking temperatures are also discussed systematically. [ABSTRACT FROM AUTHOR]

The microstructure, optical and electrical properties of sputtering-derived HfGdO high-k gate dielectric thin films as a function of the Gd doping content have been systematically investigated. X-ray diffraction (XRD) measurements have indicated that Gd doping can form a new stable cubic phase. The optical band gap of the HfGdO gate dielectrics increases gradually from 5.82 to 6.14 eV as the Gd doping concentration increases. The electrical properties, such as permittivity, oxide trapped charge density, border trap charge density and leakage current density of samples, are determined using a semiconductor device analyzer. The formation mechanism of leakage current is also discussed in detail. In addition, the interfacial properties of HfGdO/Si gate satcks were tested to establish the electrical properties. The excellent optoelectronic properties, such as the optical band gap of 5.95 eV, leakage current density of 8.33 × 10 −8 A/cm 2 at a bias voltage of 2 V, oxide trapped charge density of −1.06 × 10 12  cm −2 and a border trap charge density of zero and optimized interfacial properties were observed in the HfGdO thin films with sputtering power of 30 W, indicating that it may become a potential high-k gate dielectric in future complementary metal oxide semiconductor (CMOS) devices. [ABSTRACT FROM AUTHOR]

In this work, the band gap, interfacial properties and electrical properties of Gd doped ZrO 2 high-k gate dielectric films deposited by solution method have been systematically investigated. Results have shown that Gd doping can increase band gap energy from 5.65 to 5.92 eV and effectively restrain the formation of low-k SiO x interfacial layer between dielectric and Si substrate. Moreover, the conduction band offset is increased from 2.57 to 3.06 eV by Gd doping, which effectively reduces the leakage current density to 1.8 × 10 −6 A/cm 2 . [ABSTRACT FROM AUTHOR]

The effect of nitrogen on the band offset of sputtering-derived InZnGaO 4 (IGZO)/Si heterostructures has been systematically investigated by x-ray photoelectron spectroscopy (XPS) measurements. Elemental analysis indicates that nitrogen has been successfully incorporated into the IGZO film. By using In 3d 5/2 , In 3d 3/2 and Ga 3d core level (CL) XPS spectra as references, values of valence band offsets (Δ E v ) of have been determined to be 2.56 ± 0.02 and 2.44 ± 0.02 eV for IGZO/Si and IGZO:N/Si heterojunctions, respectively. Using the experimental band gap of 3.59 and 3.50 eV of the IGZO/Si and IGZO:N/Si, the calculated values of conduction band offset (Δ E c ) is 0.09 ± 0.01 and 0.06 ± 0.01 eV, respectively. The results indicate that nitrogen incorporation leads to the reduction in band gap and Δ E v and the slight effect on the Δ E c has also been detected. [ABSTRACT FROM AUTHOR]

Nitrogen content dependent optical constant and electrical properties of sputtering-derived HfTiON gate dielectrics on Si substrate have been investigated. By means of characterization of ultraviolet–visible spectroscopy, reduction in band gap of HfTiON film has been detected with the increase in nitrogen concentration. Electrical measurements of MOS capacitor based on Al/HfTiON/Si gate stacks have indicated that a low interface-state density with almost ignorable frequency dispersion at applied gate voltage of 1 V have been obtained for all samples. With increasing the nitrogen concentration, the improved electrical performance has been observed. For the sample with Ar/N 2 flow ratio of 20/5, rapid thermal annealing (RTA) treatment at 200 °C achieves relatively favorable excellent electrical properties in terms of low gate leakage current density and oxide charge density ( Q ox ). The conduction mechanism for 200 °C-annealed sample has been analyzed systematically. [ABSTRACT FROM AUTHOR]

Sputtering-derived amorphous InGaZnO (a-IGZO) thin films were grown on Si and glass substrates in a mixed ambient of Ar and O 2 at fixed 0.5 Pa working pressure. The influence of O 2 /Ar flow ratio on the optical and electrical properties of a-IGZO thin films has been systematically investigated by means of characterization from spectroscopic ellipsometry (SE), X-ray diffraction (XRD), scan electron microscopy (SEM), atomic force microscope (AFM), UV–vis spectroscopy, and electrical measurements. Results have shown that the band gap of the as-deposited IGZO films increases from 3.45 eV to 3.75 eV as the O 2 /Ar flow ratio increases from 0% to 20%. Blue shift in band gap and reduction in reactive index with increasing the O 2 /Ar flow ratio have been detected. Electrical measurements have indicated the increase in resistivity at higher O 2 /Ar gas flow ratio. Related mechanics about the increase in band gap and resistivity have been discussed in detail. [ABSTRACT FROM AUTHOR]