On the nature of point defect and its effect on electronic structure of rocksalt hafnium nitride films

Gu, Zhiqing; Hu, Chaoquan; Fan, Xiaofeng; Xu, Le; Wen, Mao; Meng, Qingnan; Zhao, Lei; Zheng, Xianliang; Zheng, Weitao

doi:10.1016/j.actamat.2014.08.040

Cited by 36 publications

(15 citation statements)

References 43 publications

(55 reference statements)

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“…One is the tensile stress while the compressive stress results in the peaks shifting to lower angles. The other is the Nb vacancies in overstoichiometric NbN x coatings (x > 1), since metal vacancies are found to commonly exist in the over-stoichiometric transition metal (group IVB, VB and VIB) nitride coatings (films), such as TiN x [21], ZrN x [22], NbN x [23,24], HfN x [25] and TaN x [26] (x > 1). In order to separate the respective influence of these two factors on XRD peak shifting, residual stress was determined by the sin 2 j method [27] and the (200) peaks of the d-NbN coatings with sufficient intensities were used.…”

Section: Chemical and Phase Compositions Of The Nbn X Coatingsmentioning

confidence: 99%

Microstructure, mechanical properties and oxidation behaviors of magnetron sputtered NbNx coatings

Zhang

et al. 2016

Journal of Alloys and Compounds

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Section: Chemical and Phase Compositions Of The Nbn X Coatingsmentioning

confidence: 99%

Microstructure, mechanical properties and oxidation behaviors of magnetron sputtered NbNx coatings

Zhang

et al. 2016

Journal of Alloys and Compounds

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“…It keeps stable around 9.0 9 10 3 S/cm at first and then increases to 3.7 9 10 4 S/cm suddenly around V N concentration of 15% and decreases gradually to 1.5 9 10 4 S/cm finally. The conductivity is a little higher than that of the standard nitride semiconductor materials such as gallium nitride and indium nitride [28], but the V N formed in crystal lattice could act as the donor-like defect which makes the behavior of electrical properties of substoichiometric ZrN x films be very similar to the semiconductor [29,30]. So the electric conductivity of ZrN x films can be regarded as a product of carrier concentration and mobility by the formula: r e = nql (q is charge quantity of carrier) [31].…”

Section: Electrical Propertiesmentioning

confidence: 99%

“…And the reason for the following gradual decrease in carrier concentration may come from the negative contribution of the vanish of V N . The V N could act as donor-like defects and add extra free electrons to the conduction band [30]. As the V N is filled gradually with the increase in nitrogen content, the negative contribution to the carrier concentration becomes more apparent, so the decreasing tendency is observed.…”

Section: Electrical Propertiesmentioning

confidence: 99%

Influence of Nitrogen Vacancy Concentration on Mechanical and Electrical Properties of Rocksalt Zirconium Nitride Films

Han

Lin

Chen

et al. 2017

Acta Metall. Sin. (Engl. Lett.)

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To study the influence of the nitrogen vacancy (V N ) on mechanical and electrical properties of zirconium nitride deeply, ZrN x films with different V N concentrations were synthesized on the Si (111) substrates by enhanced magnetic filtering arc ion plating. The morphologies, microstructures, residual stresses, compositions, chemical states, mechanical and electrical properties of the as-deposited films were characterized by field-emission scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectrometry, Nanoindenter and Hall effect measurements. The results showed that ZrN x films exhibited rocksalt single-phase structure within a V N concentration ranging from 26 to 5%. The preferred orientation, thickness, grain size and residual stress of the ZrN x films kept constant at different V N concentrations. Both the nanohardness and elastic modulus first increased and then decreased with the decrease in V N concentration, reaching the peaks around 16%. And the electric conductivity of the ZrN x films showed a similar tendency with nanohardness. The underlying atomic-scale mechanisms of V N concentration-dependent hardness and electric conductivity enhancements were discussed and attributed to the different electronic band structures, rather than conventional meso-scale factors, such as preferred orientation, grain size and residual stress.

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“…The details of preparation, characterization, Drude-Lorentz fitting, and computation methods were reported elsewhere. 33,40 Fig. 1(a) plots the reflectance spectra of Hf 1Àx Ta x N films at different x, wherein there is a cutoff wavelength (k Rmin ) corresponding to a distinct minimum of reflectance in the region of visible to ultraviolet wavelengths.…”

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confidence: 99%

Optical reflectivity and hardness improvement of hafnium nitride films via tantalum alloying

Huang

Zhang

et al. 2016

Applied Physics Letters

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It is found that incorporation of tantalum in a hafnium nitride film induces a tunable optical reflectivity and improves the hardness. The underlying mechanism can be illustrated by a combination of experiments and first-principles calculations. It is shown that the evolution of optical reflectivity and the increase in hardness arise from the formation of Hf1−xTaxN solid solutions and the resulting changes in the electronic structure. The increase in infrared reflectance originates from the increase in concentration of free electrons (n) because Ta (d3s2) has one more valence electron than Hf (d2s2). The sharp blue-shift in cutoff wavelength is attributed to the increase in n and the appearance of t2g → eg interband absorption. These results suggest that alloying of a second transition metal renders an effective avenue to improve simultaneously the optical and mechanical properties of transition metal nitride films. This opens up a door in preparing high-reflectance yet hard films.

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On the nature of point defect and its effect on electronic structure of rocksalt hafnium nitride films

Cited by 36 publications

References 43 publications

Microstructure, mechanical properties and oxidation behaviors of magnetron sputtered NbNx coatings

Microstructure, mechanical properties and oxidation behaviors of magnetron sputtered NbNx coatings

Influence of Nitrogen Vacancy Concentration on Mechanical and Electrical Properties of Rocksalt Zirconium Nitride Films

Optical reflectivity and hardness improvement of hafnium nitride films via tantalum alloying

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