Sputtering of W-Mo alloy under ion bombardment

１　ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｔｈｅｓｕｒｆａｃｅａｌｌｏｙｉｎｇｔｅｃｈｎｏｌｏｇｉｅｓ,ｔｈｅｓｕｒｆａｃｅｑｕａｌｉｔｙｂｙｌａｓｅｒｂｅａｍａｎｄｅｌｅｃｔｒｏｎｂｅａｍａｌｌｏｙｉｎｇｉｓｄｉｆｆｉｃｕｌｔｔｏｃｏｎｔｒｏｌａｎｄｄｉｍｅｎｓｉｏｎａｌｃｈａｎｇｅｆｏｌｌｏｗｓ．Ｔｈｅｔｈｉｃｋｎｅｓｓｏｆｔｈｅａｌｌｏｙｉｎｇｌａｙｅｒｆｏｒｍｅｄｂｙｉｏｎｉｍｐｌａｎｔａｔｉｏｎｉｓｏｎｌｙａｂｏｕｔ１μｍ,ｗｈｉｌｅｔｈａｔｐｒｏｄｕｃｅｄｂｙｉｏｎｍｅｔａｌｌｉｃｃｅｍｅｎ…     

钛基pH电极表面离子轰击处理的研究

采用离子轰击技术对钛基ｐＨ电极进行表面处理,在其表面生成以δ相和ε相为主的组织结构。离子氮化后再引入微量氧可使渗层结构中有部分氧化钛,对ｐＨ的响应好。经该工艺处理的钛基ｐＨ电极与玻璃ｐＨ电极测量ｐＨ的结果一致,而且克服了玻璃ｐＨ电极容易破碎的缺点。采用本工艺可生产性能优良的ｐＨ传感器。     

Control of macrostress σ in reactively sputtered Mo-Al-N films by total gas pressure

This article reports on the effect of the energy delivered to a growing film by bombarding ions and fast neutrals on the macrostress σ and the structure of sputtered films. To demonstrate this effect, we selected Mo-Al-N films with a low (?20 at.%) Al content reactively sputtered using an unbalanced dc magnetron with a target of 100 mm diameter at a high total pressure , low substrate bias and a high substrate ion current density . The main goal of this study was to show the reduction of σ in films sputtered at high pressures of several Pa. Under the conditions given above approximately 4 μm thick Mo-Al-N films with enhanced hardness H≈35 GPa and a very low (?−0.5 GPa) macrostress σ were successfully prepared. This result demonstrates that the enhanced hardness H of Mo-Al-N films is not caused by σ but is due to its nanostructure as shown in the XRD patterns of these films. The Mo-Al-N films with enhanced hardness are composed of a mixture of grains of different crystallographic orientations.     

Characteristic features of ion-photon emission from yttrium-iron garnets

The main parameters of the ion-photon emission (IPE) arising from the bombardment of yttrium-iron garnets (YIG) samples with Ar⁺-ions were studied. The essential difference in the spectral composition, quantum yield of emissions, and spatial distribution of radiation registered from YIG to that from samples of pure metal iron was determined. Such difference in parameters of IPE is due to contribution of new mechanisms of formation of excited particles leaving the sample during ion bombardment YIG compared with emission from a metal. It was suggested the excited atoms are formed during the decay of Me_mO_n complexes ejected from solids.     

Molecular dynamics study of deposition mechanism of cubic boron nitride

We have performed molecular dynamics simulations of bombardment of graphitic boron nitride (gBN) by energetic boron and nitrogen particles in order to examine the roles of ion bombardment in ion/plasma-assisted deposition of cubic boron nitride (cBN) thin films. We have found that the interaction of the energetic particles with gBN creates four-fold coordinated local structures (sp³-formation) inside gBN. We have also found that clusters of sp³-formations are created as a result of successive bombardment, some of which have cBN-like structures. On the basis of these results, we propose an atomic-scale model of cBN nucleation in which successive sp³-formation converts gBN into cBN.     

Ion beam modification of TiO2 films prepared by Cat-CVD for solar cell

The effects of nitrogen ion bombardment on TiO₂ films prepared by the Cat-CVD method have been studied to improve the optical and electrical properties of the material for use in Si thin film solar cells. The refractive index n and the dark conductivity of the TiO₂ film increased with irradiation time. The refractive index n of the TiO₂ film was changed from 2.1 to 2.4 and the electrical conductivity was improved from 3.4 × 10^− 2 to 1.2 × 10^− 1 S/cm by the irradiation. These results are due to the formation of Ti-N bonds and oxygen vacancies in the film.     

Influence of substrate direct current bias voltage on microcrystalline silicon growth during radio-frequency magnetron sputtering

Hydrogenated microcrystalline silicon (μc-Si:H) thin films were prepared on glass, aluminum-covered glass and Si wafer substrates at various substrate bias voltages (V_sb) between -400 and +50 V, and the influence of V_sb on their structural properties was investigated. The crystallinity (crystalline volume fraction and crystallite size) of the μc-Si:H films deposited on glass remained unchanged with respect to V_sb. For μc-Si:H films deposited on aluminum within the V_sb range of -20 to +50 V, the crystallinity also remained unchanged and showed the same crystallinity as that of the films deposited on glass substrate. However, the crystallinity of the μc-Si:H films deposited on aluminum-covered substrate was reduced as V_sb decreased from -20 to -100 V, and the film at V_sb=-400 V was completely amorphous.     

Applications of fullerene beams in analysis of thin layers

Molecular dynamics computer simulations have been employed to model ejection of particles from Ag{1 1 1} metal substrate and thin benzene overlayer bombarded by fullerene cluster projectiles. The sputtering yields are analyzed depending on the size (from C₂₀ up to C₅₄₀) and the kinetic energy (5-20 keV) of a projectile. It has been found that for clean metal substrate bombarded by 15 keV projectiles the maximum ejection is stimulated by the impact of the C₆₀ cluster. However, the size of the cluster projectile maximizing the yield depends on the kinetic energy of the cluster, shifting towards larger clusters as the impact energy increases. For a thin benzene overlayer, the yield increases monotonically with the size of the cluster within investigated range of fullerene projectiles and kinetic energies.