Reactive Gas Pulsing Process Research Articles

A mechanical TiAl/TiAlN multinanolayer coating model based on microstructural analysis and nanoindentation

A finite element model reproducing the mechanical behaviour during nanoindentation tests on Ti0.67Al0.33/Ti0.54Al0.46N multilayer coatings was developed. Coatings with two different nanoperiods (10 and 50 nm) were deposited by radio-frequency magnetron sputtering from a single sintered titanium/aluminium target using the reactive gas pulsing process. X-ray diffraction and transmission electron microscopy confirmed the multilayer stacking of the coatings. The finite element models of coatings with these two stacking periods were built considering successive hypotheses: equal thicknesses for metal and nitride nanolayers stacked without transition layer, equal thicknesses stacking with a transition layer between each metal and nitride nanolayer and finally imbalanced thicknesses stacking with a transition layer. The elastic and plastic properties of the stacked nanolayers were determined on thick monolithic coatings of metal and nitride using indentation testing and the finite element model updating method respectively. The elastic-plastic properties of the interface were introduced in the multilayer model as a rule of mixtures of the metal and nitride properties using two hypotheses: parallel or serial. For 50 nm-period film, the interface has a negligible effect on the overall indentation response. On the other hand, for the 10 nm period, the imbalanced stacking model with precise knowledge of the transition layer thickness obtained by N K-edge electron energy loss spectroscopy is required to reproduce the experimental indentation curve. Compared to classical analytical models accounting for hardness, not only the hardnesses but also the indentation moduli appear to be well predicted and evaluated in this work.

Tunable properties of SnOx sputter-deposited by RGPP and GLAD techniques: A potential candidate for photosensing and all-oxide solar cells

In this work, optical and electrical properties of tin-oxide (SnOx) thin-films were investigated for broadband photosensing and photovoltaic applications. The GLancing Angle Deposition (GLAD) and Reactive Gas Pulsing Process (RGPP) techniques were used to study the effects of the oxygen ratio variation and deposition angle on the film optoelectronic and photovoltaic properties. The deposition angle of the particle flux was kept at 80° and the injected oxygen gas concentration was tuned by changing the oxygen pulsing time from 0 to 20 s. It is found that the material band gap increases from 0.9 eV to 3.56 eV when the oxygen content increases. The deposited SnOx films exhibited improved and tuned optoelectronic properties, demonstrating their potential applications for developing alternative broadband photosensing layers and eco-friendly all-oxide solar cells. In this regard, SnOx-based photosensor and all-oxide SnOx solar cell structures were developed using the deposited thin-films. It is revealed that the prepared SnOx photosensor shows the highest responsivity of 32.7 mA/W and improved ION/IOFF ratio of 48 dB. Moreover, the optimized all-oxide SnOx solar cell demonstrates a high efficiency of 3.41 %, a short-circuit current of 14.53 mA/cm2 and an open circuit voltage of 0.49 V. These interesting results make the proposed elaboration process based on combined RGPP and GLAD techniques highly suitable for the development of high-performance optoelectronic and photovoltaic devices based on cost-effective metal oxide materials.

Tunable band-selective photodetector based on sputter-deposited SnOx thin-films: Effect of reactive gas pulsing process

In this work, high-performance SnOx band-selective photodetectors (PDs) were realized by DC magnetron sputtering technique. The reactive gas pulsing process (RGPP) was implemented with pulsing period fixed at P = 20 s to adjust tin and oxygen concentrations in the film. The impact of pulsed oxygen time on the structural, morphological and photosensing properties of SnOx-based PDs was investigated. The fabricated SnOx-based PD at a high duty cycle of 80% of P demonstrated high UV photodetection capabilities and solar-blind characteristic with a high responsivity of 21.8 mA/W, a high signal to noise ratio of 6 × 104 and a specific detectivity of about 5 × 1011 Jones. It was also revealed that the use of a short oxygen pulsing time 8 s paves the way for the realization of multispectral SnOx PD, demonstrating a high responsivity values of 36.45 mA/W, 36.4 mA/W and 34 mA/W over UV, Visible and NIR bands, respectively. This is attributed to the role of using RGPP in modulating the film optoelectronic properties from metallic to insulator when the duty cycle and thus oxygen concentration in the films changed from pure tin to overstoichiometric SnO2 compound. The prepared SnOx PDs demonstrated many advantageous features like low-noise, cost effective and high sensitivity. The obtained results proved that SnOx can be used as an alternative material for developing high-performance band-selective sensing devices.

Tunable Electrical Properties of Ti-B-N Thin Films Sputter-Deposited by the Reactive Gas Pulsing Process

Titanium-boron-nitrogen (Ti-B-N) thin films were deposited by RF reactive magnetron sputtering using a titanium diboride (TiB2) target in an argon + nitrogen mixture. The argon mass flow rate was kept constant, whereas that of nitrogen was pulsed during the deposition. A constant pulsing period of P = 10 s was used, and the introduction time of the nitrogen gas (duty cycle (dc)) was systematically varied from dc = 0 to 100% of the pulsing period. This reactive gas pulsing process allowed the deposition of Ti-B-N thin films with various boron and nitrogen concentrations. Such adjustable concentrations in the films also led to changes in their electronic transport properties. Boron and nitrogen contents exhibited a reverse evolution as a function of the nitrogen duty cycle, which was correlated with the transition from a metallic to semiconducting-like behavior. A percolation model was applied to the electrical conductivity as a function of the nitrogen pulsing parameters, assuming some correlations with the evolution of the Ti-B-N thin film nanostructure.

Controlled grain-size thermochromic VO2 coatings by the fast oxidation of sputtered vanadium or vanadium oxide films deposited at glancing angles

An original, simple and cost-effective oxidation strategy to attain thermochromic vanadium dioxide thin films is reported. This two-step procedure comprises the initial deposition of DC magnetron-sputtered vanadium or vanadium oxide films by the combination of glancing angle deposition and, if needed, reactive gas pulsing process, followed by fast oxidation of such layers in air atmosphere at high temperatures. Thanks to the careful control of the thermal treatment parameters, and taking advantage of the superior reactivity of the high surface-to-volume porous deposited structures, the formation of pure VO2 (M1) layers was achieved. The comprehensive characterization of such oxidized systems by means of scanning electron microscopy, Raman spectroscopy and scanning-transmission electron microscopy techniques such as electron energy-loss spectroscopy, not only confirmed the presence of the VO2 (M1) phase, but also allowed to shed light on the key role that reaction time plays in the selective formation of vanadium dioxide films of adjustable grain size and crystallinity. The optimal conditions to stabilize thermochromic VO2 consists in using large deposition angles (85 °) and short oxygen pulses (≤ 2 s) during the growth, followed by fast and short thermal treatments (≤ 45 s with a heating rate of 42 °C s−1) in air atmosphere at 550 °C. The metal-to-insulator response of the accomplished VO2 layers was finally evaluated by means of temperature dependent Kelvin probe force microscopy measurements, evidencing surface potential drops at heating, greater than those reported in the literature to date for VO2 thin films.

Tuning the Optical Properties of WO3 Films Exhibiting a Zigzag Columnar Microstructure

Tungsten oxide WO3 thin films are deposited by DC reactive magnetron sputtering. The Reactive Gas Pulsing Process (RGPP) associated with the GLancing Angle Deposition method (GLAD) are implemented to produce zigzag columnar structures. The oxygen injection time (tON time) and the pulsing period are kept constant. Three tilt angles α are used: 75, 80, and 85° and the number of zigzags N is progressively changed from N = 0.5, 1, 2, 4, 8 to 16. For each film, refractive index, extinction coefficient, and absorption coefficient are calculated from optical transmission spectra of the films measured in the visible region from wavelength values only. Absorption and extinction coefficients monotonously drop as the number of zigzags increases. Refractive indices are the lowest for the most grazing tilt angle α = 85°. The highest refractive index is nevertheless obtained for a number of zigzags close to four. This optimized optical property is directly correlated to changes of the microstructure, especially a porous architecture, which is favored for high tilt angles, and tunable as a function of the number of zigzags.

RELATION BETWEEN HARDNESS OF (Ti, Al)N BASED MULTILAYERED COATINGS AND PERIODS OF THEIR STACKING

This study aims to model, by using a finite element method, the relationship between the hardness and the period Λ of metal/nitride multilayer coatings (Ti0.54Al0.46/Ti0.54Al0.46N)n in order to understand the increase of the hardness at the low periods [1] and then optimise the multilayer coating architecture to obtain the best mechanical properties. A 2D axisymmetric finite element model of the Berkovich nanoindentation test was developed. The coating was designed as a stacking of Ti0.54Al0.46 and Ti0.54Al0.46N nanolayers with, in the first hypothesis, equal thickness and perfect interface. The elastoplastic behaviours of the metal and nitride layers were identified by Berkovich nanoindentation experiments and inverse analysis on thick monolayer samples. The indentation curves (P-h) obtained by this model depend on the period Λ of the stacking. Simulated (P-h) curves were compared with experimental data on 2 μm thick films with different periods Λ ranging from 10 to 50 nm deposited by RF magnetron sputtering using reactive gas pulsing process (RGPP). The model forecasts are very consistent with the experience for the largest period but the model does not reproduce the hardness increase at the lowest periods. The Λ = 10 nm coating was analysed by electron energy loss spectroscopy (EELS) on a transmission electron microscope. Results show intermixing of the layers with the presence of nitrogen atoms in the metal layer over a few nanometers [1]. It was concluded that the metal/ceramic interface plays an important role at low periods. The addition in the model of a transition layer in the metal/nitride stacking, with an elastoplastic metal/ceramic medium behaviour, allows to reproduce the nanoindentation experimental curves. The thickness of this transition layer deduced from model updating method is in very good agreement with EELS observations.

On the possibility of synthesizing multilayered coatings in the (Ti,Al)N system by RGPP: A microstructural study

Radiofrequency magnetron sputtering combined with reactive gas pulsing process was used to synthesize two titanium aluminum nitride multilayer films using a periodically controlled nitrogen flow rate changing from 0.4 to 1 sccm (sample S04-1) and from 0 to 1 sccm (sample S0-1). A metallic TiAl buffer layer was deposited on the etched substrates before the deposition to enhance their adhesion. The films were characterized using mainly transmission electron microscopy and electron diffraction. The role of the crystallinity of the buffer TiAl metallic layer deposited before gas introduction on the growth orientations is emphasized. It is shown that the formation of a multilayer structure is conditioned by stopping periodically and completely the nitrogen flow rate. Particular attention is paid to the role that residual oxygen can play on the microstructure and to transient regime that occurs when the flow rate drops from 1 sccm to 0 sccm.

Reactive co-sputtering of tungsten oxide thin films by glancing angle deposition for gas sensors

Tungsten oxide thin films exhibiting an oriented columnar architecture were prepared by reactive co-sputtering. Two opposite W and WO3 targets focused on the center of the substrate were simultaneously sputtered using opposite and oblique angles of 80° from the substrate normal. The reactive gas pulsing process was used to adjust the films electrical resistivity. Different inclined columnar structures were produced and applied as gas sensors for dodecane detection. Morphology, structure and resistivity of the films were investigated and connected to the sensing performances measured from 373 to 773 K.

Exploiting the dodecane and ozone sensing capabilities of nanostructured tungsten oxide films

Tungsten oxide thin films are grown by DC reactive magnetron sputtering combining glancing angle deposition (GLAD) and reactive gas pulsing process (RGPP). Inclined, zigzag and spiral columnar architectures are produced with various oxygen injections during the growth. The dodecane and ozone sensing properties of these tungsten oxide nanostructured active layers are comparatively studied with that of films deposited by conventional sputtering process. Microstructure, morphologies and electrical behaviors are characterized as a function of the growing conditions. As-deposited films systematically exhibit an amorphous crystal structure with a porous microstructure, which depends on the GLAD architecture. Annealing at 300 °C in air for 12 h leads to a polycrystalline structure keeping voided networks. Dodecane and ozone sensing performances are the most significant for inclined columnar architectures but they also depend on the RGPP sputtering conditions. As a result, the GLAD + RGPP combination proves to be a relevant strategy for the fabricating tungsten oxide nanostructured films as active layers with an attractive potential for gas sensors.

Structure, composition and electronic transport properties of tungsten oxide thin film sputter-deposited by the reactive gas pulsing process

Tungsten oxide thin films were prepared by DC magnetron sputtering. The reactive gas pulsing process was implemented to modify tungsten and oxygen concentrations in the films. A rectangular pulsing signal was used with a pulsing period fixed at P = 16 s, whereas the duty cycle α was systematically changed from α = 0–100% of P. The chemical composition of the films showed a gradual increase of oxygen-to-tungsten concentrations ratio from 0 to more than 3.0 as a function of the duty cycle. Films became poorly crystallized and even amorphous with an increase of the oxygen content. Similarly, a typical columnar structure was observed for pure or oxygen-rich tungsten films, which vanished when the duty cycle was higher than a few % of P. The optical transmittance in the visible range of WOx films deposited on glass also showed a progressive change from absorbent to transparent as the duty cycle was increased. Electronic transport properties including conductivity, carrier mobility and concentration also demonstrated the controlled and regular evolution of the electrical properties from metallic to insulator when the duty cycle and thus oxygen concentration in the films changed from pure tungsten to over-stoichiometric WO3 compound.

Correlation between deposition parameters of periodic titanium metal/oxide nanometric multilayers and their chemical and structural properties investigated by STEM-EELS

We analyze structure and composition of titanium-based metal/oxide periodic multilayers prepared by reactive sputtering. The reactive gas pulsing process is involved to periodically inject the oxygen gas during the multilayers deposition. This approach allows the growth of regular and tunable nanometric TiO2/Ti periods with thicknesses ranging from 14 to 50nm. The interfacial layer between oxide and metallic layers is mainly the fcc-TiO phase as clearly pointed out by transmission electron microscopy and associated electron spectroscopies. In addition, sharp transitions are produced at Ti/TiO2 interfaces (with a high density of defects) whereas the smoothest ones are obtained at TiO2/Ti interfaces. Similarly, the real-time measurements of the target voltage vs. time correlate with periodic alternations formed by a mixture of amorphous+rutile TiO2 compound, the fcc-TiO phase and the hcp metallic Ti phase through the films thickness. An abrupt transition from metallic to oxidized sputtering mode takes place when oxygen is injected and correlates with the sharp Ti/TiO2 interface. On the other hand, when oxygen is stopped, the restoration to the metallic sputtering mode is longer and corresponds to the occurrence of the fcc-TiO phase at the smooth TiO2/Ti interfaces.

Investigation of Ti0.54Al0.46/Ti0.54Al0.46N multilayer films deposited by reactive gas pulsing process by nano-indentation and electron energy-loss spectroscopy

Physical vapour deposition technology is well suited to the deposition of advanced TiAlN-based coatings. Among these thin films, multilayer systems consisting of stacked layers of metallic Ti1−xAlx and nitride Ti1−xAlxN with x around 0.5 are expected to have improved mechanical properties with respect to single nitride layers of the same composition. A set of Ti0.54Al0.46/Ti0.54Al0.46N multilayer films with five different periods Λ (from 4 to 50nm) were deposited using the reactive gas pulsing process (RGPP). This RGPP approach allows the deposition of TiAl-based alloy/nitride multilayer films by radio frequency reactive magnetron sputtering with a controlled pulsing flow rate of the nitrogen reactive gas. The coherent growth of the multilayer coatings, depending on the period, is checked by X-ray diffraction and the mechanical properties are determined by Berkovich nano-indentation and friction experiments. A model to describe the dependence of the indentation modulus M and the hardness HB on the penetration depth h, the period Λ, and the film thickness ef is proposed. The indentation modulus of the multilayer films (M at h=0 and for ef~1900nm) is found to be in the range of 340GPa<M<525GPa≈M(Ti0.54Al0.46N). For a fixed penetration depth, M follows a Hall and Petch evolution as a function of the period (4≤Λ≤50nm). The Berkovich hardness, 25GPa<HB<50GPa, also presents the same kind of evolution, and for Λ<16nm (at h=0), HB>HB (Ti0.54Al0.46N)=33GPa. Hence, a superlattice effect is clearly evidenced. Moreover, for the larger periods, the wear behaviour of these multilayered coatings seems to be dominated by the plastic deformation of the metallic layer. The multilayer coating of period Λ=10nm, which exhibits a diffraction pattern typical of superlattices and favourable mechanical properties, is more precisely investigated. Transmission electron microscopy confirms the main growth of the film along the [111] direction, and the evolution of the bonding of nitrogen in the direction normal to the rough interfaces between Ti0.54Al0.46 and Ti0.54Al0.46N layers is specified by electron energy-loss near-edge spectroscopy. Nitride nano-grains are included in the metallic layer, which attests to the mixing of nitrogen into the layers. The structure of these nano-grains presents a progressive evolution into the layer and gradually acquires a TiN-like structure near the interface. For this Λ=10nm period, the indentation modulus and hardness for different penetration depths are weakly sensitive to the multilayer film thickness.

Correlations between structure, composition and electrical properties of tungsten/tungsten oxide periodic multilayers sputter deposited by gas pulsing

W/WOx multilayered thin films have been deposited by DC reactive sputtering using the reactive gas pulsing process. It is implemented to produce regular alternations of metal-oxide compounds at the nanometric scale. Structure and growth have been investigated by high resolution transmission electron microscopy, scanning transmission electron microscopy, X-ray energy dispersive spectroscopy and electron energy loss spectroscopy. Regularity of tungsten-based alternations, quality of interfaces as well as oxygen presence through the multilayered structure have been determined and linked to the growth conditions. Chemical information was obtained from the energy dispersive X-ray spectroscopy and low-loss electron energy loss spectroscopy. As they can be related to the chemical composition of the periodic layers, the position and the broadening of the bulk plasmon peak were studied. For the smallest periods (<10 nm), the presence of oxygen has been pointed out in the metal-rich layer whereas for the thickest ones (100 nm), pure metal is only present. Finally, relationships have been established between in situ growth conditions, structural and chemical parameters and electrical properties in periodic multilayers.

Temperature dependence of electrical resistivity in oxidized vanadium films grown by the GLAD technique

Abstract Vanadium and vanadium oxide thin films are deposited by DC magnetron sputtering. A first series of pure vanadium films are prepared by glancing angle deposition (GLAD). The incident angle α of the particle flux is systematically changed from 0 to 85°. For the second series, the angle α is kept at 85° and oxygen gas is injected during the growth by means of the reactive gas pulsing process (RGPP). A constant pulsing period P = 16 s is used whereas the oxygen injection time t ON is varied from 0 to 6 s. After depositing, films are annealed in air following 11 incremental cycles from room temperature up to 550 °C. For both series, the DC electrical resistivity is systematically measured during the annealing treatment. Vanadium films sputter deposited by GLAD become sensitive to the temperature for incident angles α higher than 60°. The most significant annealing effect is observed for films prepared with α = 85° with a strong increase of resistivity from 2.6 × 10 − 5 to 4.9 × 10 − 3 Ωm. It is mainly assigned to the oxidation of GLAD vanadium films, which is favoured by the high porous morphology produced for the highest incident angles. The resistivity vs. temperature evolution is also measured and related to the occurrence of the VO 2 phase. By combining GLAD and RGPP processes, the reversible variation of resistivity associated to the VO 2 phase is even more pronounced. Oxygen pulsing during deposition and the voided structure produced for the highest incident angles enhance the oxidation of vanadium through the films thickness. The porous architecture by GLAD and the oxygen injection by RGPP have to be carefully controlled and optimized for the growth of vanadium oxide compounds, especially to favour the formation of the VO 2 phase.

Structural investigations of iron oxynitride multilayered films obtained by reactive gas pulsing process

Multilayered Fe–O–N films were deposited on glass and silicon substrates using reactive magnetron sputtering with a reactive gas pulsing process. The argon and nitrogen flow rates were kept constant during sputtering of a pure iron target while the oxygen flow rate was pulsed during deposition. To determine the film composition, Rutherford backscattering spectrometry was used. X-ray diffraction revealed the formation of a face-centered cubic (fcc) structure with a lattice parameter close to that of γ″′-FeN. In addition, traces of iron oxide Fe1−xO (wüstite) have been detected in some films. Transmission electron microscopy provides clear evidence for the formation of a multilayer structure for all the coatings. Electron energy loss spectroscopy was used to check that each layer contains both nitrogen and oxygen. The local environment of iron atoms studied by 57Fe Mössbauer spectrometry at 300K indicated that the samples consist mainly of an iron oxynitride phase with a NaCl-type structure where oxygen atoms partially substitute nitrogen ones. However, in accordance with the X-ray diffraction results, a small amount of iron nitride (FeN) and oxide (Fe1−xO) is also present in the nitrogen-rich and oxygen-rich layers, corresponding to the sputtering time (toff) and (ton). Thus the hypothesis of a multilayer structure, type (γ″′-FeN/Fe1−xO) can be excluded because the spectra Mössbauer always reveal the presence of iron oxynitride.

Tungsten Oxide Thin Films Sputter Deposited by the Reactive Gas Pulsing Process for the Dodecane Detection

The DC reactive magnetron sputtering of a metallic tungsten target was performed in an argon + oxygen atmosphere for depositing tungsten oxide thin films. In order to control the oxygen concentration in the films, the reactive gas pulsing process, namely RGPP, was implemented. Rectangular pulses were used with a constant pulsing period T = 16 s whereas the duty cycle α (time of oxygen injection to pulsing period T ratio) was systematically changed from 0 to 100% of T. This pulsing injection of the reactive gas allowed a gradual evolution of the films composition from pure metallic to over-stoichiometric WO3+ɛ’ compounds. These WOx films were sputter deposited on commercial MSP 769 Heraeus platforms so as to be used as a sensor for the dodecane gas. It is shown that the sensing performances carried out at 573K can be adjusted as a function of the duty cycle used during the deposition stage. The relationship between sensing properties and physic-chemical behaviours of the films was especially discussed.

Effect of RGPP process on properties of Cr–Si–N coatings

CrSiN films were deposited by reactive radio frequency magnetron sputtering in an Ar+N2 gas mixture. The nitrogen gas was injected in the deposition chamber using two methods: the classical constant injection and pulsed injection, the latter known as the reactive gas pulsing process (RGPP). Argon gas was continuously injected, whereas nitrogen gas was pulsed during the deposition. The RGPP was used to adjust the chemical composition and, consequently, allowed the improvement of the coating characteristics. The effect of process parameters such as silicon content and gas pulsing conditions (especially duty cycle α) on the crystallographic structure, chemical composition and morphology of the CrSiN layers is reported. It was found that the surface morphology evolves from a pyramid-like feature for 100% duty cycle to a typical cauliflower-like aspect, when duty cycle decreases to 84%. For shorter duty cycles, the growth produced a denser coating, with round and finer clusters.

Flash annealing influence on structural and electrical properties of TiO2/TiO/Ti periodic multilayers

Multilayered structures with a 40nm period composed of titanium and two different titanium oxides, TiO and TiO2, were accurately produced by DC magnetron sputtering using the reactive gas pulsing process. These multilayers were sputtered onto Al2O3 sapphire to avoid substrate compound diffusion during flash annealing (ranging from 350°C to 550°C). Structure and composition of these periodic TiO2/TiO/Ti stacks were investigated by X-ray diffraction, X-ray photoemission spectroscopy and transmission electronic microscopy techniques. Two crystalline phases α-Ti and fcc-TiO were identified in the metallic-rich sub-layers whereas the oxygen-rich ones were composed of a mixture of amorphous and rutile TiO2 phase. DC electrical resistivity ρ measured for temperatures ranging from 25 to 200°C was influenced by the thermal treatments. The temperature coefficients of resistance of these periodic TiO2/TiO/Ti multilayers were modified from 11.7×10−04 to −8.81×10−04K−1. Local changes of crystallinity were reported and the resistivity responses of these annealed films could be linked to the typical electrical behavior of a metal–oxide mixture.

Enhanced tunability of the composition in silicon oxynitride thin films by the reactive gas pulsing process

Silicon oxynitride thin films were sputter deposited by the reactive gas pulsing process. Pure silicon target was sputtered in Ar, N2 and O2 mixture atmosphere. Oxygen gas was periodically and solely introduced using exponential signals. In order to vary the injected O2 quantity in the deposition chamber during one pulse at constant injection time (TON), the tau mounting time τmou of the exponential signals was systematically changed for each deposition. Taking into account the real-time measurements of the discharge voltage and the I(O*)/I(Ar*) emission lines ratio, it is shown that the oscillations of the discharge voltage during the TON and TOFF times (injection of O2 stopped) are attributed to the preferential adsorption of the oxygen compared to that of the nitrogen. The sputtering mode alternates from a fully nitrided mode (TOFF time) to a mixed mode (nitrided and oxidized mode) during the TON time. For the highest injected O2 quantities, the mixed mode tends toward a fully oxidized mode due to an increase of the trapped oxygen on the target. The oxygen (nitrogen) concentration in the SiOxNy films similarly (inversely) varies as the oxygen is trapped. Moreover, measurements of the contamination speed of the Si target surface are connected to different behaviors of the process. At low injected O2 quantities, the nitrided mode predominates over the oxidized one during the TON time. It leads to the formation of Si3N4−yOy-like films. Inversely, the mixed mode takes place for high injected O2 quantities and the oxidized mode prevails against the nitrided one producing SiO2−xNx-like films.