Electron microscopy and Rutherford backscattering spectrometry characterisation of 6H SiC samples implanted with He

6H SiC single crystals were implanted at room temperature with 1 MeV He⁺ up to a fluence of 2 × 10¹⁷ at./cm². RBS-channeling analysis with a 2 MeV He⁺ beam indicated the formation of extended defects or the generation of point defects at a constant concentration over a depth of about 1 μm. Electron microscopy characterisation revealed the presence of two amorphous buried layers at depths of about 1.75 and 4.8 μm. They are due to the implantation and to the analysing RBS beam, respectively. No extended planar or linear faults were found in the region between the surface and the first amorphous layer. However, at the surface, a 50 nm thick amorphous layer was observed in which crystalline inclusions were embedded. Electron diffraction and HREM data of the inclusions were typical for diamond. These inclusions were even found in the crystalline SiC material below this layer, however at a reduced density.     

特征X射线能谱法测定Fe^＋注入小麦种子的深度

用１１０ｋｅＶ Ｆｅ＾＋离子束垂直注入小麦种胚后，在扫描电子显微镜上沿种子纵沟剖面，在不同深度上测量Ｆｅ元素被激发出的特征Ｘ射线强度分布，结果表明分布呈指数衰减，与晶体中的热扩散分布相类似，并对此进行了讨论。     

Compositional analysis of atom beam co-sputtered metal-silica nanocomposites by Rutherford backscattering spectrometry

Metal:SiO₂ (metal: Ni, Ag, Au) nanocomposite films of different compositions have been prepared by atom beam co-sputtering. The estimation of composition of films is done theoretically using sputtering yield and relative area of metal and SiO₂. The sputtering yields used for estimation of composition are calculated by three theoretical methods: Monte Carlo simulations (SRIM code), Sigmund’s theory and Sigmund’s theory modified by Anderson and Bay. Rutherford backscattering spectrometry (RBS) is also used to analyze the composition of the nanocomposite films. RUMP simulations of RBS data are performed. The errors in theoretical calculations and RBS results are estimated. It is found that SRIM is more appropriate for Ni:SiO₂ nanocomposite films, while modified Sigmund’s theory based method is better for Ag:SiO₂ and Au:SiO₂ nanocomposite films. The possible sources of errors in theoretical methods with respect to experimental (RBS) results are also discussed.     

Eu,Dy共掺杂长余辉发光材料中稀土离子价态的研究

利用同步辐射X射线吸收近边结构(XANES)对Eu,Dy共掺杂硅酸盐体系长余辉发光材料中的稀土离子的价态进行分析，结果表明有 2价和 3价的Eu离子存在，但未发现 1价的Eu离子，而Dy离子则始终以 3价形式存在，未发现 4价Dy离子存在。这说明空穴传输模型还存在许多值得商榷的问题。该研究为进一步研究长余辉材料的发光机理提供了实验依据。     

Ion implantation of rare earth ions for light emitters

We discuss the excitation and deexcitation processes for solid state optical emitters. At present, there is considerable interest in depositing a material system, which is compatible to silicon microelectronics processing and which emits electroluminescence (EL). We will compare the EL results of rare earth doped transistors in silicon with doped insulators and doped wide bandgap semiconductors, especially Er in Si (a source for 1.5 μm) as well as Er and Tb in SiO₂, Si₃N₄ and AIN, which are sources for infrared and visible light. The most impressive results are achieved by RE doped GaN film devices, which cover the entire visible spectrum.     

微束背散射分析元素微区分布的研究

微束背散射分析元素微区分布的分析方法使上海原子核研究所的质子微探针能在微区内综合使用质子激发Ｘ射线荧光和背散射等多种核效应，为样品由轻元素到重元素的全面无损、双微（微区、微量）分析提供了依据。应用该方法还测量了Ｓｉ３Ｎ４／ＳｉＣ复合陶瓷材料，证明了该分析方法的可靠性。     

Characterization of optical coatings by Rutherford backscattering spectrometry and elastic recoil detection analysis

The thicknesses of optical coatings vary between a few hundred Å and a few μm. Ion-beam techniques are ideally suited for probing this thickness range and in this work we discuss the use of Rutherford backscattering spectrometry (RBS) and elastic recoil detection analysis (ERDA) for characterizing optical coatings such as ZnS, YF₃,Y₂O₃, C and Ge on silicon and germanium substrates. A general evaluation of the favourable features as well as the limitations of RBS and ERDA ion beam analysis for characterizing optical coatings is given.     

Nuclear tracks in garnets studied by means of Rutherford backscattering and X-ray diffraction

(Y, La)₃(Fe, Ga)₅O₁₂ epitaxial garnet films on (111) Gd₃Ga₅O₁₂ substrates irradiated with ²³⁸U ions of 1.4 MeV/u specific energy in the dose range 10¹⁰ cm^?2 to 3 × 10¹¹ cm^?2 were measured by means of Rutherford backscattering and double-crystal X-ray diffraction before and after thermal annealing in oxygen. The nuclear track diameter of 10 nm confining a cylindrical volume of highly disordered material caused by each ion impact has been deduced from the comparison of the backscattering spectra of the irradiated and unirradiated film areas. The fraction of randomly backscattered ions due to the irradiation-induced damage as well as the lattice expansion perpendicular to the crystal surface caused by irradiation-induced lateral compressive stress are proportional to the ion dose. After thermal annealing the comparison of the almost identical backscattering yield of the irradiated areas and the unirradiated film regions demonstrates a nearly perfect recrystallization of the damaged track volumes.     

掺稀土硫酸盐的剂量响应特性

测量了掺稀土碱土硫酸盐的热释光和光释光剂量响应曲线,利用复合作用剂量响应模型,得出了剂量响应的非线性参数。实验发现剂量响应的线性与稀土离子的种类及其引起的缺陷结构相关。掺入Eu的磷光体材料的一次作用因子R接近于1,说明其响应是亚线性,以一次作用响应为主;掺入Tm和Dy的磷光体材料的一次作用因子R小于0．5,说明其响应是超线性,以二次作用响应为主。热释光峰温愈高,R因子越小,超线性愈严重,表明二次作用响应所占的份额增加。实验中光释光剂量响应的非线性参数和TL的参数基本相同。     

As离子束混合形成硅化钨的卢瑟福背散射分析

本工作用卢瑟福背散射研究了离子束混合方法形成硅化钨的条件。通过对热烧结和离子束混合法的比较,结合X射线衍射分析相结构的结果,指出离子束混合法可降低形成二硅化钨所需的退火温度。观察到氧杂质对形成条件的影响,简单讨论了离子束混合形成硅化物的机理。     

Kinetic study of wet oxidation of Si0.5Ge0.5 alloy by Rutherford backscattering spectroscopy

1IntroductionSilicongermaniamalloyshavereceivedgreatattentioninrecentdecadefOrtheirpo-tentialapplicationinadvancedelectronicandoptoe1ectronicdeyices[1~41.Theoxidationbehaviorofthismaterial,however,continuestobeatroublesomeissuethatimPedesitstAnelydevelopment.Previousresearchesdemonstratedthathighgermaniamcontent,inthealloyandlowtemperaturecouldformaAnxtureoxidelayeIofSiO, GeOgst'].WhengermaniumconcentrationisloweIonlySiO2fo...d[7'8].Inthepresentstudy,OkidationhasbeenpeIformedat8oO'Cand9…     

Range parameters of slow gold ions implanted into light targets

Interatomic potentials for Au-C, Au-B, Au-N and Au-Si systems, calculated with density-functional theory (DFT) methods, have been used to evaluate the range parameters of gold in B, Si, BN and SiC films at energies of about 10-400 keV. The potentials have been employed to describe scattering angles of a projectile and to calculate the nuclear stopping powers and the higher moments of the energy, transferred in single collisions. Utilizing these findings the range parameters have been obtained by the standard transport theory and by Monte-Carlo simulations. A velocity proportional electronic stopping was included into the consideration. The approach developed corresponds completely to the standard classical scheme of the calculation of range parameters. Good agreement between the computed range parameters and available experimental data allow us to conclude that correlation effects between the nuclear and electronic stopping can be neglected in the energy range in question. Moreover, it is proven for the first time that the model by Grande, et al. [P.L. Grande, F.C. Zawislak, D. Fink, M. Behar, Nucl. Instr. and Meth. B 61 (1991) 282], which relies on the importance of correlation effects, contains inherent contradictions.     

Range profiles of medium and heavy ions implanted into SiO2

As, Cs, Xe, Eu and Yb have been implanted into SiO₂ in a typically 10–200 keV energy range. The implanted profiles were analysed using the Rutherford backscattering technique. The obtained projected ranges (R)_p) and projected range stragglings (ΔR_p) are compared with recent predictions due to Ziegler, Biersack and Littmark. While good agreement is obtained between the theoretical and experimental values of R_p, significant deviations are found for ΔR_p.     

The range distribution and annealing behavior of Er ions implanted in silicon-on-insulator

The range distribution for energetic 400 keV Er ions implanted in silicon-on-insulator (SOI) at room temperature were measured by means of Rutherford backscattering followed by spectrum analysis. The damage distribution and annealing behavior of implanted Er ions in SOI at the energy of 400 keV with dose of 5 × 10¹⁵ cm⁻² were obtained by Rutherford backscattering technique. It has been found that the damage around the SOI surface had been almost removed after annealed in nitrogen atmosphere at 900 °C, and a lot of Er atoms segregate to the surface of sample with the recrystallization of surface Si of SOI sample after annealing at 900 °C.     

Determination of stopping power for ions by backscattering from thin targets

A new procedure is presented for extracting the stopping power from the widths of a number of backscattering spectra. It can be applied irrespectively of the magnitude of the kinematic factor. For this method we introduce a function dependent on four parameters, the shape of which is sufficiently adaptable not to cause a relevant bias. This is demonstrated by fitting this function to the proton stopping power tables of Janni: for all 92 elements we list the fit parameters together with the mean and the maximum deviation. By computer simulation it is shown that the projectile energies in the backscattering measurements have to cover a certain range — depending on the kinematic factor — to give the correct stopping cross section. Finally, we applied this procedure to the measurement of the stopping cross section of Al for He-ions.