Assisting Ion Energy Research Articles

Optical band-gap and associated Urbach energy tails in defected AlN thin films grown by ion beam sputter deposition: Effect of assisted ion energy

AIN thin films were grown by ion beam sputter deposition in reactive assistance of N+/N2+ ions on Si (100) substrates. During deposition, assisted ion energy (EA) was varied as 90 eV and 120 eV with a post deposition exposure to N2 plasma. The resultant films were characterized by grazing incidence x-ray diffraction (GIXRD) for their structure and atomic force microscopy (AFM) for their root mean square (rms) surface roughness (δ). UV-VIS spectrophotometry was carried out to explore their optical band-gap with associated Urbach (EU) and weak absorption tail (EWAT) energies. Our results show that, AlN thin film grown with 90 eV reactive ion assistance possesses larger optical band gap (Eg) of 5.3 eV associated with comparatively narrower band tails when compared to those AlN thin film samples which were grown for 120 eV reactive ion assistance. These optical band-gaps are further correlated with corresponding Urbach energy tails which can be used as a measure of disorder in microstructure of the film. Also, appropriate optimization of energy tails substantiates the possibility of band gap engineering as per the requirement of different thin film devices. Copyright © 2017 VBRI Press.

Plasmonic characteristics of niobium nitride thin films modulated by assisting ions

NbNx films were prepared by dual ion beam sputter deposition. Different assisting ion current density Ja and assisting ion energy Ea were used to modulate the structural and dielectric properties of the films. All the films are of fcc structure, and assisting ions can improve their crystallinity. Higher Ja and Ea can reduce the screened plasma frequency and the optical energy loss of the films. Importantly, with appropriate experimental parameters, the NbNx films exhibit tunable dual epsilon-near-zero behavior. The assisting ions cause the variation of the carrier concentration in the films, and then modulate the dielectric properties of the films. Our results show that NbNx films can be applied in different fields by tailoring their plasmonic properties by assisting ions.

Effects of assisting ions on the structural and plasmonic properties of ZrNx thin films

Plasmonic ZrNx thin films were prepared by ion beam assisted deposition (IBAD). The effects of the assisting ion current (Ia), assisting ion energy (Ea) and the partial flow rate ratio of N2/Ar (r) on the structure and dielectric properties of the films were investigated. The results show that all the films are fcc-structured, and the IBAD films exhibit a preferred fcc-(1 1 1) orientation. Nitrogen content of the films can be improved by higher Ea and r, and reduced by higher Ia. Higher Ia, Ea or r can reduce the crossover frequency at which the films turn from dielectric to metallic phase, and reduce the loss function of the films. Moreover, the plasmonic quality factor can also be modulated by these parameters. The main mechanism of the modulation is the variation of the carrier concentration in the films. Our study demonstrates that the IBAD-ZrNx thin films have considerable plasmonic performances, and their dielectric and plasmonic properties can be modulated from visible to near infrared region by assisting ion beam.

Structural and dielectric properties of ion beam deposited titanium oxynitride thin films

Titanium oxynitride ( $${\hbox {TiO}}_{x}{\hbox {N}}_{y}$$ ) thin films were fabricated by ion beam-assisted sputtering deposition. Effects of oxygen contribution, assisting ion energy ( $$E_{\mathrm{a}}$$ ), assisting ion beam current ( $$I_{\mathrm{a}}$$ ) on the microstructure and dielectric behavior of the films were analyzed. The results show that increasing O content made the films to turn from fcc-TiN (111)-oriented to fcc $${\hbox {TiO}}_{x}{{\hbox {N}}}_{y}$$ (220)-oriented. Proper $$E_{\mathrm{a}}$$ and low $$I_{\mathrm{a}}$$ can enhance the (220) orientation in $${\hbox {TiO}}_{x}{{\hbox {N}}}_{y}$$ thin films. The increase in oxygen content leads to the red-shift of plasmonic resonant frequency and makes the films more dielectric. Higher $$E_{\mathrm{a}}$$ and $$I_{\mathrm{a}}$$ make the $${\hbox {TiO}}_{x}{{\hbox {N}}}_{y}$$ films more metallic. Atomic composition is an important factor underlying the results. The study provides a method to control the plasmonic properties of oxynitride films in a wide range by atomic composition and assisting ions.

Ion beam modification of plasmonic titanium nitride thin films

Titanium nitride is regarded as an alternative plasmonic material for its tunability and other high performances. In this work, we prepared \(\hbox {TiN}_{x}\) thin films by ion beam assisted deposition and studied the effects of assisting ion energy \(E_\mathrm{a}\) on the structural, electrical, optical, and plasmonic properties of the films. The results show that the bombardment of assisting ions causes higher crystallinity and higher resistivity. Both the experimental and fitting results show that assisting ions can improve the plasmonic performance of \(\hbox {TiN}_{x}\) thin films. Higher \(E_\mathrm{a}\) leads to lower carrier concentration, lower plasma frequency, and lower optical losses. With \(E_\mathrm{a}\) increasing, the energy loss function shifts toward low photon energy. Importantly, IBAD–\(\hbox {TiN}_{x}\) can serve as a promising plasmonic material in visible and near-IR region, and its plasmonic properties can be effectively tuned by assisting ions energy.

Molecular dynamics study of the effect of substrate temperature and Ar ion assisted deposition on the deposition of amorphous TiO2 films

This paper has investigated the impact of the substrate temperature and Ar ion assisted deposition on the surface structure formation mechanism and the film properties during the amorphous TiO2 thin film deposition process with the molecular dynamics simulation method. The results show that the reduction of the surface roughness happen when the energy of Ar ions assisted is increased or the substrate temperature rises, and also the film density on surface is changed with the increasing of Ar ions energy and substrate temperature. It is also found that the Volmer-Weber (island) growth mode of films is promoted by the lower Ar ion energy and higher substrate temperature when the substrate has an island structure. The assisted Ar ion has power of making a flat surface and increasing the local temperature. Besides, it will influence the growth mode with the change of surface atom mobility. With a high assisted Ar ion energy the Volmer-Weber (island) growth mode is inhibited, which will be conducive to the formation of more smooth film surface.

Effects of sputtering and assisting ions on the orientation of titanium nitride films fabricated by ion beam assisted sputtering deposition from metal target

Ion beam assisted titanium nitride (TiN) film has attracted much attention because its fast texture and high conductivity can be effectively applied in all-conductive superconducting coated conductor. In this work, TiN films were prepared by ion beam sputtering deposition from a metal titanium target. Effects of sputtering ion energy, assisting ion energy, assisting ion current and deposition temperature on the orientation and surface morphology were analyzed. The results indicate that assisting ion is an important factor in orientation selection, and high assisting ions and low assisting ion current could enhance the crystallinity. However, too high assisting ion energy and current can destroy the crystallinity in IBAD–TiN. This orientation selection can be attributed to the energy exchange between assisting ions and adatoms.

Effects of assisting ion energy and current on MgO films fabricated by ion-beam-assisted sputtering deposition

MgO films were prepared by ion-beam-assisted sputtering deposition from a metal magnesium target. Effects of assisting ion energy Ea and current density Ja on the orientation and surface morphology of the films were analysed in detail. The results show that moderate Ea and Ja could enhance the crystallinity, but high Ea and Ja can destroy the crystallinity of the films. Assisting ion energy Ea is an important factor for orientation selection, and the formation of (100) orientation needs high Ea and low Ja.

Influence of assisted ion energy on surface roughness and mechanical properties of boron carbon nitride films synthesized by DIBSD

The BCN thin films were produced by dual ion beam sputtering deposition (DIBSD). The influence of assisted ion energy on surface roughness and mechanical properties of BCN films were investigated. The surface roughness was determined by atomic force microscopy (AFM) and the mechanical properties of BCN firms were evaluated by nano-indentation in N 2 gas. The composition, structure and chemical bonding of the BCN thin films were analyzed by using energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), laser Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). These films appeared as amorphous structure. As a result, the BCN films with the smoothest surface ( R a = 0.35 nm and R p–v = 4.4 nm) and the highest nano-hardness of 30.1 GPa and elastic modulus of 232.6 GPa were obtained at 200 eV and 12 mA with N 2:Ar = 1:1, and the chemical composition of this BCN film was 81 at.% B, 14 at.% C and 5 at.% N. Moreover, several bonding states such as B–N, B–C and C–N were observed in BCN thin films.

Effects of ion energy on ion beam assisted deposition textured yttria stabilized zirconia buffer layer of coated conductor

High quality biaxially textured yttria stabilized zirconia (YSZ) thin films, as buffer layers of coated conductors, were deposited on hastelloy substrates by ion beam assisted deposition (IBAD) method with different assisting ion energy E i. The roles of assisting ion beam and the influences of ion energy E i on the structure of the films were studied. It was found that both the out-of-plane alignment and in-plane texture of the IBAD-YSZ films are sensitive to the variation of E i. The results are explained in the paper by different damage tolerance of the differently oriented grains to ion bombardment.

SAXS analysis of graphitic amorphous carbon

We report on the study of amorphous carbon films using the small angle X-ray scattering (SAXS) technique. The films were deposited by ion beam assisted deposition at different assisting ion energies, ranging from 50 eV to 200 eV. The film density was determined by Rutherford back-scattering (RBS) and the film thickness was measured by a stylus profilometer. The film density increases as the assisting ion energy used during deposition increases. Small angle X-ray scattering results revealed large scatter centers within the matrix, increasing in size with assisting ion energy. The mean distance between those centers was found to be about 2.5 nm independent of the deposition conditions. The gyration radius (Rg) is in the 18 nm to 25 nm range, while the film is about 100 nm thick.

Effect of assisted ion energy on properties of silicon oxide thin film deposited by dual ion‐beam sputtering

AbstractA silicon oxide thin film barrier was prepared with different oxygen ion energies, and its chemical composition, surface morphology, optical, and barrier property related to the deposition condition were characterized and discussed. Our study showed that in O2‐assisted process the stoichiometric silicon oxide thin film was obtained at a critical deposition condition of 100 eV oxygen ion energy. The thin film deposited at the critical condition showed the lowest surface roughness giving similar or higher optical transmittance than that of pure polycarbonate substrate. The boiling and tensile tests performed on the thin film deposited using assisted ions prior to the deposition process showed improvement in the adhesion between the oxide barrier layer and the polymer substrate. In addition, interface domination for improving the barrier properties of silicon oxide thin film was achieved through introduction of dual ion‐beam sputtering without pretreatment. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

Advanced ion beam technology for versatile oxide thin film formation

Various oxide films, such as SnO 2 , In 2 O 3 , Al 2 O 3 , SiO 2 , ZnO, and Sn-doped In 2 O 3 (ITO) have been deposited on glass and polymer substrates by advanced ion beam technologies including ion-assisted deposition (IAD), hybrid ion beam, ion beam sputter deposition (IBSD), and ion-assisted reaction (IAR). Physical and chemical properties of the oxide films and adhesion between films and substrates were improved significantly by these technologies. By using the IAD method, non-stoichiometry, crystallinity, and microstructure of the films were controlled by changing assisted oxygen ion energy and arrival ratio of assisted oxygen ion to evaporated atoms. IBSD method has been carried out for understanding the growth mode of the films on glass and polymer substrate. Relationships between microstructure and electrical properties in ITO films on polymer and glass substrates were intensively investigated by changing ion energy, reactive gas environment, substrate temperature, etc. Smooth-surface ITO films ( R rms ⩽ 1 nm and R p−v ⩽ 10 nm) for organic light-emitting diodes were developed with a combination of deposition conditions with controlling microstructure of a seed layer on glass. IAR surface treatment enormously enhanced the adhesion of oxide films to polymer substrate. In the case of Al 2 O 3 and SiO 2 films, the oxygen and moisture barrier properties were also improved by IAR surface treatment. The experimental results of the oxide films prepared by the ion beam technologies and its applications will be represented in detail.

Material properties and growth control of undoped and Sn-doped In 2O 3 thin films prepared by using ion beam technologies

Undoped (IO) and Sn-doped In 2O 3 (ITO) films have been deposited on glass and polymer substrates by an advanced ion beam technologies including ion-assisted deposition (IAD), hybrid ion beam, ion beam sputter deposition (IBSD), and ion-assisted reaction (IAR). Physical and chemical properties of the oxide films and adhesion between films and substrates were improved significantly by these technologies. By using the IAD method, non-stoichiometry and microstructure of the films were controlled by changing assisted oxygen ion energy and arrival ratio of assisted oxygen ion to evaporated atoms. Relationships between structural and electrical properties in ITO films on glass substrates were intensively investigated by using the IBSD method with changing ion energy, reactive gas environment, and substrate temperature. Smooth-surface ITO films ( R rms ≤ 1 nm and R p–v ≤ 10 nm) for organic light-emitting diodes were developed with a combination of deposition conditions with controlling microstructure of a seed layer on glass. IAR surface treatment enormously enhanced the adhesion of oxide films to polymer substrate. The different dependence of IO and ITO films' properties on the experimental parameters, such as ion energy and oxygen gas environment, will be intensively discussed.

イオンビームアシスト蒸着法による窒化ニオブ薄膜の配向制御

The orientation of the niboium nitride thin films was controlled by the assisting ion energy and its incident angle to the substrate in ion beam assisted deposition technique. The films were deposited under the different ion incident angle and ion energy, and their orientation was evaluated by x-ray diffraction. The work function was also measured by Kelvin probe. As a result, it was found that the c-axis of the crystallites were grown along the direction perpendicular to the ion incident angle. The tendency was more prominent when the ion energy was increased. However, the difference in the work function among the deposited samples was not large, probably due to the fact that the films were still polycrystaline.

Ion beam assisted growth of fluorite type oxide template films for biaxially textured HTSC coated conductors

Biaxially aligned growth was studied by a dual-ion-beam sputtering method for fluorite type (Zr/sub 0.85/Y/sub 0.15/O/sub 1.93/ (YSZ), Hf/sub 0.74/Yb/sub 0.26/O/sub 1.87/, CeO/sub 2/), pyrochlore type (Zr/sub 2/Sm/sub 2/O/sub 7/), and rare earth C type (Y/sub 2/O/sub 3/, Sm/sub 2/O/sub 3/) oxide films on polycrystalline Ni-based alloy substrates. Cube-textured (all axes aligned with a <100> axis substrate normal) films were obtained by low energy (<300 eV) ion bombardment at low temperatures (<300/spl deg/C). The assisting ion energy dependence of crystalline alignment was discussed in connection with lattice energies for these oxide crystals. Furthermore, a fluorite-like type oxide (Zr-X-O) was found to have a shorter time constant of texture evolution than YSZ. I/sub c/=98A (J/sub c/=0.65 MA/cm/sup 2/) was obtained for a 1.5 /spl mu/m thick Y-123 film on Zr-X-O.

702 100nm膜厚のCNx膜とDLC膜の疲労特性の評価(摩擦と損傷)(機素潤滑設計部門企画セッション)

Fatigue properties of 100 nm thickness-DLC and CNx coatings which were made under different coating conditions were evaluated with an AFM micro-fatigue test which was developed by authors. Higher ion energy of assisted ion as Ar and N for DLC and CNx respectively provided smaller hardness and shorter life. When assisted ion energy is relatively high, the depth of delamination wear scar is equal to the depth of maximum tangential stress. However, when assisted ion energy is relatively small, the depth of delamination wear scar is different from the depth of maximum tangential stress.

Ion Beam Induced Growth Structure of Fluorite Type Oxide Films for Biaxially Textured HYSC Coated Conductors

AbstractBiaxially aligned film growth by dual-ion-beam sputtering methods were studied for fluorite type (Zr0.85Y0.15O1.93(YSZ), Hf0.74Yb0.26O1.87, CeO2), pyrochlore type (Zr2Sm2O7), and rare-earth C type (Y2O3, Sm2O3) oxides on polycrystalline Ni-based alloy substrates. Cubetextured (all axes aligned with a &lt;100&gt; axis substrate normal) films were obtained for fluorite and pyrochlore ones by low energy (&lt;300 eV) ion bombardment at low temperatures (&lt; 300 °C). Besides, cube textured Y2O3 films were obtained in far narrower conditions with a quite low energy (150 eV)-ion bombardment at the temperature of 300 °C. The assisting ion energy dependence was discussed in connection with lattice energies for these oxide crystals.

Ion Beam Induced Growth Structure of Fluorite Type Oxide Films for Biaxially Textured htsc Coated Conductors

AbstractBiaxially aligned film growth by dual-ion-beam sputtering method were studied for fluorite type (Zr0.85Y0.15O1.93(YSZ), Hf0.74Yb0.26O1.87, CeO2), pyrochlore type (Zr2Sm2O7), and rare-earth C type (Y2O3, Sm2O3) oxides on polycrystalline Ni-based alloy substrates. Cube-textured (all axes aligned with a &lt;100&gt; axis substrate normal) films were obtained for fluorite and pyrochlore ones by low energy (&lt;300 eV) ion bombardment at low temperatures (&lt; 300 °C). Besides, cube textured Y2O3 films were obtained in far narrow conditions with a quite low energy (150 eV)-ion bombardment at the temperature of 300°C. The assisting ion energy dependence was discussed in connection with lattice energies for these oxide crystals.

Effects of bombardment on optical properties during the deposition of silicon nitride by reactive ion-beam sputtering

Thin silicon nitride (Si(1_x)N(x)) films were synthesized without substrate heating by means of reactive argon-ion sputtering of either silicon or a silicon nitride target in the 1000-1500-eV energy range at a nitrogen partial pressure of 1.3 × 10(-2) Pa and with simultaneous nitrogen ion-assisted bombardment in the 300-500-eV low energy range. The extinction coefficient and refractive index of the films were directly dependent on the N(+) ion-to-atom arrival ratio, assisted ion energy, film growth rate, and indicated a correlation with film stoichiometry and disorder. Si(3)N(4) films were obtained for N(+) ion/Si atom arrival ratios from 0.6 to 1.7 and for different Si:N atom arrival rates and had a refractive index as high as 2.04 (633 nm) and a low hydrogen content as indicated by IR spectra.