Atomic layer deposition of nanolaminate oxide films on Si

Tallarida, Massimo; Weisheit, Martin; Kolanek, Krzysztof; Michling, Marcel; Engelmann, Hans‐Jürgen; Schmeißer, Dieter

doi:10.1007/s11051-011-0319-x

Cited by 25 publications

(20 citation statements)

References 25 publications

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“…XPS spectra were obtained by Theta Probe Thermo Fisher Scientific spectrometer with a monochromatic Al Kα X‐ray source (1486 eV). In order to remove the surface carbon contaminations and OH‐groups that are almost always observed after ALD the previous heating at T = 300 °C for 30 s in a vacuum chamber of an XPS spectrometer was used. The effect of the film composition on the bandgap was evaluated using the REELS technique with incident electron energies of 1000 eV.…”

Section: Methodsmentioning

confidence: 99%

Structural, chemical and electrical properties of ALD‐grown Hf_xAl_1–xO_y thin films for MIM capacitors

Chernikova

Markeev

Lebedinskiǐ

et al. 2014

Physica Status Solidi (b)

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In this paper atomic-layer deposition (ALD) Hf x Al 1-x O y thin films with a wide range of metal components concentrations (x ¼ 0.2À0.8) for metal-insulator-metal (MIM) capacitors were investigated with emphasis on the chemical properties and phase composition. It was shown by X-ray diffraction (XRD) that all films are amorphous. X-ray photoelectron spectroscopy (XPS) revealed the same energy position with respect to the valence-band maximum of Al2p and Hf4f lines and a continuous shift of O1s and O-KLL lines toward the higher binding energy (0.45 and 2.2 eV, respectively) with increase of Al content. Both the shape and position of O1s and O-KLL lines indicated the inability to deconvolute it on sublines related to the binary oxides. The calculated modified Auger parameter indicated the change of the ionicity of the bonding in Hf x Al 1-x O y films with change of the composition. Thus, it was proposed that Hf x Al 1-x O y films in all the studied composition range represent amorphous solid solutions. The continuous change of energy bandgap measured by reflected electron energy loss spectroscopy (REELS) from $6.5 eV for Al 2 O 3 to $5.4 eV for HfO 2 and XRD data do not contradict this assumption. Correlation between structural properties of Hf x Al 1-x O y films and electrical properties of MIM capacitors based on them was also shown, that is, continuous change in capacitance density (from 3.1 to 7.4fF/mm 2 ), leakage current density and quadratic voltage coefficient of capacitance with composition change was observed.

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Section: Methodsmentioning

confidence: 99%

Structural, chemical and electrical properties of ALD‐grown Hf_xAl_1–xO_y thin films for MIM capacitors

Chernikova

Markeev

Lebedinskiǐ

et al. 2014

Physica Status Solidi (b)

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“…17 The tetrakis-dimethylamino-Hf (TDMAHf) precursor was maintained at room temperature as in previous experiments it was observed that repeated heating-cooling cycles lead to degradation of the precursor. The GDS and the ALD reactor are described elsewhere.…”

Section: B Ald Reactor Setup and Operationmentioning

confidence: 99%

In situ study of the atomic layer deposition of HfO2 on Si

Kolanek¹,

Tallarida²,

Michling³

et al. 2011

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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Physical and electrical characteristics of atomic-layer deposition-HfO2 films deposited on Si substrates having different silanol Si-OH densities J. Vac. Sci. Technol. A 31, 01A132 (2013); 10.1116/1.4769206 Low temperature growth of high-k Hf-La oxides by remote-plasma atomic layer deposition: Morphology, stoichiometry, and dielectric properties J. Vac. Sci. Technol. A 30, 01A147 (2012); 10.1116/1.3665419 X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy investigation of Al-related dipole at the HfO 2 / Si interface J. Appl. Phys. 105, 024102 (2009); 10.1063/1.3066906 Photoelectron spectroscopic analysis of Hf-silicate/ Si O 2 ∕ Si stacks deposited by atomic layer chemical vapor deposition J.The authors investigated in situ the initial stages of the atomic layer deposition (ALD) growth of HfO 2 on Si(001)/SiO 2 substrates by using tetrakis-di-methyl-amino-Hf and H 2 O as precursors. The surface morphology and the chemical and electronic properties of HfO 2 ultrathin films were studied after each ALD cycle by surface-sensitive techniques. Atomic force microscopy image analysis was performed by analyzing the height-height correlation function (HHCF), the root mean square surface roughness, and the surface fractal dimension, as function of the number of ALD cycles. Parameters directly related to HHCF, e.g., surface width, correlation length, local slope, and roughness exponent, were calculated and used for determination of scaling exponents. A complex behavior of all parameters up to the eighth ALD cycle was evidenced. High-resolution synchrotron radiation photoemission spectroscopy was applied to characterize the chemical nature of Si/SiO 2 /HfO 2 interface. Changes arising in the Si 2p, O 1 s, and Hf 4f core level lines after each ALD cycle up to the complete formation of two layers of HfO 2 were observed. The thickness of the growing HfO 2 layer was calculated to estimate the growth per cycle to approximately 0.1 nm/cycle. By means of ultraviolet photoemission spectroscopy, variations of valence band maximum and secondary electron cutoff after each ALD cycle were observed and the presence of an interfacial dipole was pointed out. Finally, the loss function onset of electron energy loss spectroscopy changed during ALD because of bandgap variations from SiO 2 to HfO 2 . By combining all experimental results a new and fully comprehensive growth model of ALD during the initial stages was developed.

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“…Thin aluminum oxide (Al 2 O 3 ) layers deposited by atomic layer deposition (ALD) have been investigated for several applications like surface passivation or encapsulation in organic and inorganic photovoltaic devices [1–2], interfacial buffering for high-k dielectrics [3–4], organic memories [5], and nano-laminates [6] as well as work function modification [7], gas diffusion barrier [8] or corrosion protection [9]. Recently, there is a growing activity in covering photo-electrodes or electrodes by ultra-thin Al 2 O 3 ALD layers for electrochemical energy generation and storage systems [10] in order to enhance the efficiency and durability of such devices.…”

Section: Introductionmentioning

confidence: 99%

Ellipsometry and XPS comparative studies of thermal and plasma enhanced atomic layer deposited Al₂O₃-films

Haeberle¹,

Henkel²,

Gargouri³

et al. 2013

Beilstein J. Nanotechnol.

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SummaryWe report on results on the preparation of thin (<100 nm) aluminum oxide (Al2O3) films on silicon substrates using thermal atomic layer deposition (T-ALD) and plasma enhanced atomic layer deposition (PE-ALD) in the SENTECH SI ALD LL system. The T-ALD Al2O3 layers were deposited at 200 °C, for the PE-ALD films we varied the substrate temperature range between room temperature (rt) and 200 °C. We show data from spectroscopic ellipsometry (thickness, refractive index, growth rate) over 4” wafers and correlate them to X-ray photoelectron spectroscopy (XPS) results. The 200 °C T-ALD and PE-ALD processes yield films with similar refractive indices and with oxygen to aluminum elemental ratios very close to the stoichiometric value of 1.5. However, in both also fragments of the precursor are integrated into the film. The PE-ALD films show an increased growth rate and lower carbon contaminations. Reducing the deposition temperature down to rt leads to a higher content of carbon and CH-species. We also find a decrease of the refractive index and of the oxygen to aluminum elemental ratio as well as an increase of the growth rate whereas the homogeneity of the film growth is not influenced significantly. Initial state energy shifts in all PE-ALD samples are observed which we attribute to a net negative charge within the films.

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Atomic layer deposition of nanolaminate oxide films on Si

Cited by 25 publications

References 25 publications

Structural, chemical and electrical properties of ALD‐grown Hf_xAl_1–xO_y thin films for MIM capacitors

Structural, chemical and electrical properties of ALD‐grown Hf_xAl_1–xO_y thin films for MIM capacitors

In situ study of the atomic layer deposition of HfO2 on Si

Ellipsometry and XPS comparative studies of thermal and plasma enhanced atomic layer deposited Al₂O₃-films

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Atomic layer deposition of nanolaminate oxide films on Si

Cited by 25 publications

References 25 publications

Structural, chemical and electrical properties of ALD‐grown HfxAl1–xOy thin films for MIM capacitors

Structural, chemical and electrical properties of ALD‐grown HfxAl1–xOy thin films for MIM capacitors

In situ study of the atomic layer deposition of HfO2 on Si

Ellipsometry and XPS comparative studies of thermal and plasma enhanced atomic layer deposited Al2O3-films

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Structural, chemical and electrical properties of ALD‐grown Hf_xAl_1–xO_y thin films for MIM capacitors

Structural, chemical and electrical properties of ALD‐grown Hf_xAl_1–xO_y thin films for MIM capacitors

Ellipsometry and XPS comparative studies of thermal and plasma enhanced atomic layer deposited Al₂O₃-films