Transparent polycrystalline monoclinic HfO2 dielectrics prepared by plasma assisted pulsed laser deposition

Zhang, Ying; Sun, Jian; Hu, Zhigao; Yu, Wenyan; Xu, Ning; Wu, Jifeng

doi:10.1116/1.3673783

Cited by 3 publications

(3 citation statements)

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“…Ta introduction into HfO 2 films has significantly improved crystallization temperature. Yu et al [87] have stated that crystallization temperature of HfTaON thin films deposited by a dual ion beam sputtering deposition technique (DIBSD) is above 1100 • C, while HfO 2 crystallizes at ≈ 400 • C. Ta-doped HfO 2 creates substitutional Ta incorporated in HfO 2 [66] and defect chemistry is likely as follows:…”

Section: Ta-dopingmentioning

confidence: 99%

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Hf-Based High-κ Dielectrics: A Review

KOL

Oral

2019

Acta Phys. Pol. A

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In the last decades, the number of transistors per chip with integrated circuits has increased leading to reduction in the thickness of silicon dioxide used as gate dielectrics. However, at small dielectric thicknesses leakage current formation has begun due to the quantum tunneling effect. Thus, it became essential to replace SiO2 with alternative dielectrics with high dielectric constant to maintain the same capacitance at higher gate dielectric thicknesses. This review analyzes alternative high-κ dielectric materials substituting for SiO2. For this reason, the properties of materials with high dielectric constant are compared to SiO2 with a special emphasis on HfO2, since it is the most promising high-κ dielectric to replace SiO2. The fundamental points concerning HfO2 gate dielectrics are their high dielectric constant and their thermodynamic stability when in contact with Si. In this article, properties of HfO2 fabricated with different coating methods and doped with different elements such as N, Si, Al, Ti and Ta have been compared and discussed. In the conclusion part, we have summarized the results of characterization obtained by X-ray diffraction, scanning electron microscopy, leakage current density-voltage (J-V ), capacitance-voltage (C-V ) and UV-vis spectroscopy of HfO2 thin films.

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Section: Ta-dopingmentioning

confidence: 99%

“…of results of different coating methods[43,58,[62][63][64][65][66][67][68][69][70][71][72][73][74][75][76]. × 10 −8 A/cm 2 at 1 V EOT= 2.73 nm at 700 • C…”

mentioning

confidence: 99%

Hf-Based High-κ Dielectrics: A Review

KOL

Oral

2019

Acta Phys. Pol. A

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“…Overall, these representative process-dependent differences illustrate how achieving dense nanoscale-thick thin films of HfO 2 with bulk-like optical properties has been a challenge. The ability to controllably deposit thin-film HfO 2 while maintaining bulk-like optical properties is expected to further enable thermally resistant device development involving, for example, semiconductor-integrated circuits, electronics, optoelectronics, magneto-electronics, and nanophotonics. − ,− …”

Section: Introductionmentioning

confidence: 99%

Nanoscale-Thick Thin Films of High-Density HfO₂ for Bulk-like Optical Responses

Sun

Jones

Grant

et al. 2021

ACS Appl. Nano Mater.

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The high refractive index, broadband transparency, and low spectral absorption of HfO 2 (hafnia) make it a suitable choice for thermally stable nanoscale optical filters, UV mirrors, and antireflection coatings. However, achieving dense thin films of HfO 2 with bulk-like optical properties has been a challenge due to differences in film stoichiometric and spatial uniformity at nanoscale thicknesses. Here, we assess HfO 2 thin films (i.e., <200 nm thicknesses) prepared using pulsed laser deposition (PLD) at different substrate temperatures (20−675 °C) and the associated chemical, structural, and optical properties are reported. X-ray diffraction analysis reveals that nanoscale-thick thin films of HfO 2 deposited at an ambient substrate temperature (20 °C) using PLD are amorphous with embedded nanocrystallites, whereas films deposited on heated substrates are polycrystalline monoclinic HfO 2 . For the films deposited on heated substrates, further analysis shows that the nanocrystalline phase does not change with increasing substrate temperatures; however, the texture of the crystalline orientation changes to favor (111) at 300−675 °C from the initial (002) orientation at ambient substrate temperature. Such differences in nanoscale-thick thin-film HfO 2 PLD process-dependent amorphousness, crystallinity, and surface textures discussed here exhibit minimal influence on the resulting broadband optical properties (250 nm−30 μm). Furthermore, we show that the complex refractive index of high-density nanoscale-thick thin-film HfO 2 prepared at an ambient substrate temperature using PLD resembles that of bulk HfO 2 responses. The achievement of fully stoichiometric, high-density, thin-film HfO 2 from PLD is expected to further enable thermally robust nanoscale photonic device integration involving low-dimensional high-performance optical and optoelectronic applications.

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