Band offsets in HfTiO/InGaZnO4 heterojunction determined by X-ray photoelectron spectroscopy

He, Gang; Chen, X.F.; Lv, Jianguo; Fang, Zebo; Liu, Y.M.; Zhu, Kejia; Sun, Zhaoqi; Liu, M.

doi:10.1016/j.jallcom.2015.04.059

Cited by 12 publications

(5 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The obtained E g opt values for amorphous films were equal to 3.54 eV and 3.37 eV for (Hf 0.52 Ti 0.48 )Ox and (Hf 0.29 Ti 0.71 )Ox, respectively. According to the literature [6,11,18,22,29,40,41,56], thin films based on a mixture of two oxides with significantly different values of band gap energy (with a wide and narrow energy gap) can be a material with a modified (tailored) value of this parameter. Jiang and others [6] showed that for mixed HfO 2 -TiO 2 thin films with an amorphous phase, the values of E g opt were in the range from 3.59 to 3.77 eV.…”

Section: Resultsmentioning

confidence: 99%

“…One of the effective ways of increasing the crystallization temperature is combining HfO 2 with another complementary gate materials, such as titanium dioxide (TiO 2 ) [6]. Based on some references from the last ten years [6,12,13,18,19,[27][28][29][30][31], it can be noted that doping HfO 2 with TiO 2 can lead to receiving a higher dielectric constant and improvement of electrical properties. In turn, TiO 2 is an attractive material due to its very high dielectric constant (ε r ~ 80-110) and high crystallization temperature [6,13,22].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The effect of post-process annealing on optical and electrical properties of mixed HfO2–TiO2 thin film coatings

Obstarczyk

Kaczmarek

Mazur

et al. 2019

J Mater Sci: Mater Electron

View full text Add to dashboard Cite

In this paper a comparison of electrical and optical properties of mixed hafnium-titanium oxides is described. Thin films were deposited with the use of the magnetron co-sputtering method. For further analysis (Hf 0.52 Ti 0.48)Ox and (Hf 0.29 Ti 0.71) Ox coatings, which were amorphous directly after the deposition process, were chosen,. Moreover, post-process annealing was also performed in order to compare the electrical and optical properties of amorphous and nanocrystalline thin films with the same material composition. It was found that the phase transition from amorphous to orthorhombic HfTiO 4 occurred in the case of (Hf 0.52 Ti 0.48)Ox coating at 650 °C. In turn, the phase transition to TiO 2-anatase was observed at the temperature of 600 °C in the case of (Hf 0.29 Ti 0.71)Ox thin film. The leakage current for both amorphous coatings was in the range of 10 −7-10 −8 A/cm 2. After additional annealing and phase transition, the leakage current slightly decreased for (Hf 0.29 Ti 0.71)Ox thin film, while in the case of (Hf 0.52 Ti 0.48)Ox sample the resistance switching effect was observed. The dielectric constant was equal to 24 and 25 for amorphous (Hf 0.52 Ti 0.48)Ox and (Hf 0.29 Ti 0.71)Ox films, respectively. However, after the phase transition it decreased to 15 for (Hf 0.52 Ti 0.48)Ox and increased to 51 for (Hf 0.29 Ti 0.71)Ox film. The results of optical studies showed that amorphous thin films were well transparent in a visible light range with an average transparency of ca. 85%. After the phase transition to HfTiO 4-orthorhombic and TiO 2-anatase, a slight decrease in the transparency level by 3% and a redshift of the cutoff wavelength was observed. Moreover, additional annealing caused small changes of the optical band gap energy, refractive index and extinction coefficient.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The effect of post-process annealing on optical and electrical properties of mixed HfO2–TiO2 thin film coatings

Obstarczyk

Kaczmarek

Mazur

et al. 2019

J Mater Sci: Mater Electron

View full text Add to dashboard Cite

show abstract

“…40,45,[111][112][113][114][115][116][117][118][119][120][121][122] Generally, a new dielectric is employed without an actual knowledge of the relative condition and valence band offsets. [114][115][116][117][118][119][120][121][122] Two recent reviews of advances in AOS TFTs suggested that more work was needed on gate dielectrics development for next generation TFT devices. 23,24 Materials with a high dielectric constant (high-K) are desirable in IGZO TFTs, since the higher capacitance can reduce the effect of interface traps, and therefore reduce the device operating voltage.…”

Section: B Band Offset Importancementioning

confidence: 99%

Energy band offsets of dielectrics on InGaZnO4

Hays

Gila

Pearton

et al. 2017

Applied Physics Reviews

View full text Add to dashboard Cite

Thin-film transistors (TFTs) with channels made of hydrogenated amorphous silicon (a-Si:H) and polycrystalline silicon (poly-Si) are used extensively in the display industry. Amorphous silicon continues to dominate large-format display technology, but a-Si:H has a low electron mobility, l $ 1 cm 2 /V s. Transparent, conducting metal-oxide materials such as Indium-Gallium-Zinc Oxide (IGZO) have demonstrated electron mobilities of 10-50 cm 2 /V s and are candidates to replace a-Si:H for TFT backplane technologies. The device performance depends strongly on the type of band alignment of the gate dielectric with the semiconductor channel material and on the band offsets. The factors that determine the conduction and valence band offsets for a given material system are not well understood. Predictions based on various models have historically been unreliable and band offset values must be determined experimentally. This paper provides experimental band offset values for a number of gate dielectrics on IGZO for next generation TFTs. The relationship between band offset and interface quality, as demonstrated experimentally and by previously reported results, is also explained. The literature shows significant variations in reported band offsets and the reasons for these differences are evaluated. The biggest contributor to conduction band offsets is the variation in the bandgap of the dielectrics due to differences in measurement protocols and stoichiometry resulting from different deposition methods, chemistry, and contamination. We have investigated the influence of valence band offset values of strain, defects/vacancies, stoichiometry, chemical bonding, and contamination on IGZO/dielectric heterojunctions. These measurements provide data needed to further develop a predictive theory of band offsets. Published by AIP Publishing.

show abstract

“…Figure 3a-c show the CL spectra of Zn 2p 3/2 , In 3d 5/2 and the VBM (inset) for the a-IGZO film, ITO film and ITON film, respectively. The VBM values of a-IGZO, ITO and ITON are calculated by linearly fitting the leading edge of the E V and the flat energy distribution and obtaining the intersection of the two lines [32]. As shown in Figure 3a, it is found that the Zn 2p 3/2 of the bulk a-IGZO film is located at 1021.55 eV, and the VBM value of 2.34 eV is deduced from the VB spectra via linear fitting as described above.…”

Section: Resultsmentioning

confidence: 99%

Enhancing the Carrier Mobility and Bias Stability in Metal–Oxide Thin Film Transistors with Bilayer InSnO/a-InGaZnO Heterojunction Structure

Huang,

Chen,

Sun

et al. 2024

Micromachines

View full text Add to dashboard Cite

In this study, the electrical performance and bias stability of InSnO/a-InGaZnO (ITO/a-IGZO) heterojunction thin-film transistors (TFTs) are investigated. Compared to a-IGZO TFTs, the mobility (µFE) and bias stability of ITO/a-IGZO heterojunction TFTs are enhanced. The band alignment of the ITO/a-IGZO heterojunction is analyzed by using X-ray photoelectron spectroscopy (XPS). A conduction band offset (∆EC) of 0.5 eV is observed in the ITO/a-IGZO heterojunction, resulting in electron accumulation in the formed potential well. Meanwhile, the ∆EC of the ITO/a-IGZO heterojunction can be modulated by nitrogen doping ITO (ITON), which can affect the carrier confinement and transport properties at the ITO/a-IGZO heterojunction interface. Moreover, the carrier concentration distribution at the ITO/a-IGZO heterointerface is extracted by means of TCAD silvaco 2018 simulation, which is beneficial for enhancing the electrical performance of ITO/a-IGZO heterojunction TFTs.

show abstract

Band offsets in HfTiO/InGaZnO4 heterojunction determined by X-ray photoelectron spectroscopy

Cited by 12 publications

References 26 publications

The effect of post-process annealing on optical and electrical properties of mixed HfO2–TiO2 thin film coatings

The effect of post-process annealing on optical and electrical properties of mixed HfO2–TiO2 thin film coatings

Energy band offsets of dielectrics on InGaZnO4

Enhancing the Carrier Mobility and Bias Stability in Metal–Oxide Thin Film Transistors with Bilayer InSnO/a-InGaZnO Heterojunction Structure

Contact Info

Product

Resources

About