Effect of O2/Ar gas flow ratio on the optical properties and mechanical stress of sputtered HfO2 thin films

Jena, S.; Tokas, R.B.; Misal, J. S.; Rao, K. Divakar; Udupa, D. V.; Thakur, S.; Sahoo, N. K.

doi:10.1016/j.tsf.2015.08.062

Cited by 57 publications

(22 citation statements)

References 48 publications

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“…Additional annealing caused the occurrence of tensile stress in (Hf 0.52 Ti 0.48 )Ox and (Hf 0.29 Ti 0.71 )Ox. The type of stress occurring in the annealed coatings was determined on the basis of ∆d parameter from the following equation [40,47,48]:…”

Section: Resultsmentioning

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

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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.

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Section: Resultsmentioning

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

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“…Electrical and optical properties.- Table II 18,190,191 AlN (RI = 1.8-2.2, k = 5.7-9.5), 84,86,88,[97][98][99][100][101] and BeO films (RI = 1.67-1.72, k = 6.5-6.8). 184,192 Relative to SiO 2 , all the investigated dielectrics have substantially higher values of RI and k. Relative to SiN:H, however, only HfO 2 has a significantly higher RI and k.…”

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confidence: 99%

Review—Investigation and Review of the Thermal, Mechanical, Electrical, Optical, and Structural Properties of Atomic Layer Deposited High-kDielectrics: Beryllium Oxide, Aluminum Oxide, Hafnium Oxide, and Aluminum Nitride

Gaskins

Hopkins

Merrill

et al. 2017

ECS J. Solid State Sci. Technol.

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Atomic layer deposited (ALD) high-dielectric-constant (high-k) materials have found extensive applications in a variety of electronic, optical, optoelectronic, and photovoltaic devices. While electrical, optical, and interfacial properties have been the primary consideration for such devices, thermal and mechanical properties are becoming an additional key consideration for many new and emerging applications of ALD high-k materials in electromechanical, energy storage, and organic light emitting diode devices. Unfortunately, a clear correspondence between thermal/mechanical and electrical/optical properties in ALD high-k materials has yet to be established, and a detailed comparison to conventional silicon-based dielectrics to facilitate optimal material selection is also lacking. In this regard, we have conducted a comprehensive investigation and review of the thermal, mechanical, electrical, optical, and structural properties for a series of prevalent and emerging ALD high-k materials including aluminum oxide (Al 2 O 3 ), aluminum nitride (AlN), hafnium oxide (HfO 2 ), and beryllium oxide (BeO). For comparison, more established silicon-based dielectrics were also examined, including thermally grown silicon dioxide (SiO 2 ) and plasma-enhanced chemically vapor deposited hydrogenated silicon nitride (SiN:H). We find that in addition to exhibiting high values of dielectric permittivity and electrical resistance that exceed those of SiO 2 and SiN:H, the ALD high-k materials exhibit equally exceptional thermal and mechanical properties with coefficients of thermal expansion ≤ 6 × 10 -6 / • C, thermal conductivites (κ) of 3-15 W/m K, and Young's modulus and hardness values exceeding 200 and 25 GPa, respectively. In many cases, the observed extreme thermal/mechanical properties correlate with the presence of crystallinity in the ALD high-k films. In contrast, some of the electrical and optical properties correlate more strongly with the percentage of ionic vs. covalent bonds present in the high-k film. Overall, the ALD high-k dielectrics investigated concurrently exhibit compelling thermal/mechanical and electrical/optical properties. The drive to reduce gate leakage currents in highly scaled complementary metal-oxide-semiconductor (CMOS) transistors has led to the exploration and development of a wide variety of high-dielectricconstant (high-k) materials to replace silicon dioxide (SiO 2 ) as the insulating gate dielectric material.1-8 Many of these same high-k materials have found additional applications in future non-CMOS logic and memory storage products such as solid-state electrolytes in resistive switching devices, 9,10 tunnel barriers in spin-transport devices, 11 and as a ferroelectric in magnetoelectric devices. While electrical, physical, and thermodynamic properties have clearly been a key consideration in all of the above applications, thermal properties have become an additional important consideration for higk-k dielectrics as aggressive dimensional scaling of devices has created the need to dissipate ...

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“…However, an important problem for oxide films is that it is easy to lose oxygen in preparation [1][2][3][4], which causes the chemical mismatch to affect the performance of the film. The effects of the oxygen content on their optical properties for high refractive index oxide film materials such as TiO 2 , HfO 2 , Ta 2 O 5 and ZrO 2 were investigated [5][6][7][8][9][10]. Meanwhile, LaTiO 3 films also has a high refractive index [11], excellent stability and the wide transmission range of 360 to 7000 nm [12].…”

Section: Introductionmentioning

confidence: 99%

Effects of oxygen flow on properties of La₂Ti₂O_7−x films

Yang

et al. 2019

Mater. Res. Express

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In order to obtain the relationship between the properties and the oxygen flow rate of La 2 Ti 2 O 7−x film, the films were prepared by electron beam evaporation with various oxygen flow rates on Si and quartz substrates. The effects of oxygen flow on the properties of La 2 Ti 2 O 7−x film were analyzed by XRD, XPS, optical constant and laser damage test. The result shows that the La 2 Ti 2 O 7−x film lose oxygen and lead to the transition of Ti 4+ to Ti 3+ in oxygen-free environment. When the oxygen flow rate is greater than 4 sccm, the content of Ti 4+ is stable. The refractive index of La 2 Ti 2 O 7−x films decreases with the increase of oxygen flow rate and stabilizes at oxygen flow rate greater than 4 sccm. The extinction coefficient of film deposited in oxygen-free environment is less than 10 −4 . As the oxygen flow rate increases, the film absorption is further improved to reach 10 −5 at wavelengths longer than 350 nm. The laser damage threshold of films increased with increasing oxygen flow and the maximum value is 18.35 J cm −2 .

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Effect of O2/Ar gas flow ratio on the optical properties and mechanical stress of sputtered HfO2 thin films

Cited by 57 publications

References 48 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

Review—Investigation and Review of the Thermal, Mechanical, Electrical, Optical, and Structural Properties of Atomic Layer Deposited High-kDielectrics: Beryllium Oxide, Aluminum Oxide, Hafnium Oxide, and Aluminum Nitride

Effects of oxygen flow on properties of La₂Ti₂O_7−x films

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Effect of O2/Ar gas flow ratio on the optical properties and mechanical stress of sputtered HfO2 thin films

Cited by 57 publications

References 48 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

Review—Investigation and Review of the Thermal, Mechanical, Electrical, Optical, and Structural Properties of Atomic Layer Deposited High-kDielectrics: Beryllium Oxide, Aluminum Oxide, Hafnium Oxide, and Aluminum Nitride

Effects of oxygen flow on properties of La2Ti2O7−x films

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Effects of oxygen flow on properties of La₂Ti₂O_7−x films