Critical Thickness Threshold in HfO&lt;sub&gt;2&lt;/sub&gt; Layers

Besson, P.; Loup, V.; Salvetat, T.; Rochat, N.; Lhostis, S.; Favier, S.; Dabertrand, K.; Cosnier, V.

doi:10.4028/www.scientific.net/ssp.134.67

Cited by 6 publications

(8 citation statements)

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“…The values of thickness obtained ͑2.9 nm for HfO 2 , 2.1 nm for TaN, and 10.6 nm for poly-Si͒ correspond to the targeted ones. Moreover, the mass density extracted for the TaN layer is 11.2 g/cm 3 . This value is significantly lower than the bulk density of TaN in its facecentered cubic ͑fcc͒ crystalline phase, which is 15.93 g/cm 3 .…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, the mass density extracted for the TaN layer is 11.2 g/cm 3 . This value is significantly lower than the bulk density of TaN in its facecentered cubic ͑fcc͒ crystalline phase, which is 15.93 g/cm 3 . 4 This may be due to the partial crystallization of the layer or to the presence of contaminants.…”

Section: Resultsmentioning

confidence: 99%

“…For each sample, the sum of the two interfacial layer thicknesses ͑nearly 1 nm for each͒ and the TaN thickness is roughly equal to the targeted TaN thickness. The mass density in the central TaN layer is evaluated at z E-mail: clement.gaumer@cea.fr 12.6 g/cm 3 . We obtain a lower value for both interfacial layers, which is 10.7 g/cm 3 .…”

Section: Resultsmentioning

confidence: 99%

“…The mass density in the central TaN layer is evaluated at z E-mail: clement.gaumer@cea.fr 12.6 g/cm 3 . We obtain a lower value for both interfacial layers, which is 10.7 g/cm 3 . No variation due to the spike annealing is observed whatever the TaN thickness is.…”

Section: Resultsmentioning

confidence: 99%

“…To complement this investigation, we performed attenuated total reflection-Fourier transform IR ͑ATR-FTIR͒ spectroscopy as the shape of the HfO 2 absorption bands depended on the crystalline state. 3 Overall stack composition was checked by Auger electron spectroscopy ͑AES͒. In this work, we paid attention to the behavior of the nitrogen and oxygen atoms in the gate stack.…”

Section: Methodsmentioning

confidence: 99%

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Chemical and Structural Properties of a TaN/HfO[sub 2] Gate Stack Processed Using Atomic Vapor Deposition

Gaumer

Martínez

Lhostis

et al. 2009

J. Electrochem. Soc.

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In this work, we investigate the crystalline structure and the chemical properties of a “metal/high k ” gate stack with TaN as the gate electrode and HfO2 as the dielectric. Both TaN and HfO2 were deposited using atomic vapor deposition. We show that a 3 nm thick layer of HfO2 is crystallized when it is integrated, whereas it is amorphous as deposited. Increasing the TaN thickness increases the amount of the TaN crystalline face-centered cubic phase. Concerning the gate-stack chemistry, oxygen and nitrogen diffusion between the layers is shown. This occurs during the gate electrode deposition for all TaN thicknesses. We show that the gate stacks, including thick TaN layers, are not chemically stable under the spike annealing used for dopant activation because oxygen and nitrogen diffusion is increased by this thermal treatment. Gate stacks with a thinner TaN layer are much more stable under annealing because they are already partially oxidized before annealing.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%