离子辐照单晶Si损伤效应的研究

回顾了低能离子注入单晶Si经由核弹性碰撞引起的损伤特征及其常规的研究方法,介绍了快重离子辐照单晶Si经由电子能损引起的损伤特点及研究现状,并对该领域的研究作了展望. The radiation damage in silicon induced by low energy ion implantation was briefly reviewed together with a short introduction to the common techniques in the area. The damage characteristics of swift heavy ion irradiation in silicon and its investigations were introduced with emphasis on the effects induced by processes of electronic energy losses. It is shown that swift heavy ion can induce defects far beyond the projected range and up to 28 MeV/μm the electronic energy ...     

低能Co离子注入单晶ZnO的光致发光特性

采用离子注入法研究了Co离子注入ZnO晶体的光致发光效应。 对离子注入后的样品在Ar气保护下进行退火处理, 退火温度为700 ℃, 退火时间为10 min, 在其光致发光谱中观察到了406和370 nm的紫光发射峰。 对比了Co, Cu离子分别注入的ZnO晶体的光致发光谱, 观测到二者的光致发光谱类似。 同时, 研究了Co离子注入剂量对样品发光性质的影响, 结果表明随注入剂量的增加绿色发光中心逐渐向低能边偏移, 分析认为绿色发光中心的偏移与离子注入后ZnO晶体的禁带宽度发生改变相关。 In this paper, ion implantation techniques were used to study the photoluminescence(PL) of the Co implanted crystal ZnO. After Co ion implanted, the samples were annealed at 700 ℃ for 10 min in Ar gas flow. It was observed violet emission peak of 406 and 370 nm in the PL spectrum. The PL spectra of the ZnO crystal samples which were implanted by Co ions and Cu ions, respectively, have been compared and observed that the PL spectrum of the Co implanted ZnO is similar to that of the Cu implanted ZnO. We studied the influence of implantation dose on the PL of the Co implanted ZnO and found that the green luminescence centre shifted with increasing of implantation dose. It is concluded that the shift of the green luminescence centre is related to the change of ZnO band gap which was caused by ion implantation.     

辐照诱变对小麦生理学效应的影响

以小麦品种小偃81为材料, 利用低能N+离子, 60Co-γ射线以及紫外线UV-C等为诱变源, 对种子胚部进行辐照处理。 研究其对小麦发芽势、 发芽率、 根长及苗高等生理指标的影响。 以辐照后的幼苗为材料研究了低能N+注入对过氧化氢酶（CAT）、 过氧化物酶（POD）、 超氧化物歧化酶（SOD）活性及还原型谷胱甘肽（GSH）含量的影响。 研究结果表明: N+注入后种子活力先升高后降低, 苗高在5×1017 N+/cm2时显著低于对照; 60Co和紫外线辐照对种子活力有较显著的影响, 辐照后的根长和苗高均显著低于对照; N+束辐照后的幼苗CAT酶活随剂量的变化规律性不明显, POD和SOD酶活总体趋势随剂量的增加先升高后降低, GSH含量随剂量的增大先降低后升高。 由此可知, 辐照诱变可以诱导小麦一系列的生理变化。60Co-γ射线和紫外线UV C对小麦胚根的伤害较大, 导致幼苗在后期大量死亡。N+注入对小麦的损伤效应较60Co和紫外线γ射线和紫外线UV-C小, 一定注量的N+注入处理可促进小麦生长。 In this paper, the biological effects,such as germination percentage, germination index and the length of seedlings and roots were investigated by using low energy N+, 60Co- γ rays and ultraviolet UV C to irradiate the embryos of wheat seeds （Xiaoyan81）. The anti oxidative enzyme system (CAT,POD, SOD) and GSH content were studied as well. The results show that the vitality of seed increased and then reduced with increasing the dosage of N+ ion implantation. The length of roots and seedlings were significantly higher than control. The seed vigor was significant effected after irradiated by 60Co-γ rays and ultraviolet UV-C, but the length of roots and seedlings were significantly lower than control. After N+ implantation, the changing pattern of CAT was not obviously. The enzymatic activity of POD and SOD were increased at low dosage and reduced at high dosage. The content of GSH was reduced and then raised. The results proved that the damage induced by γ ray and UV C to the radicle of wheat was severe that result in a large number of seedling died. However the damage induced by N+ implantation was lower than that by rays and UV C irradiation. Certain dosage of ion implantation can promote the growth of wheat.     

Implant Depth Influence on InGaAsP/InP Double Quantum Well Intermixing Induced by Phosphorus Ion Implantation

We investigate quantum well intermixing of a double-quantum-well structure caused by phosphorus ion implantation by means of photoluminescence （PL）. The ion implantation is performed at the energy of 120keV with the dose ranging from 1 × 10^11 to 1 × 10^14/cm^2. The rapid thermal annealing is performed at the temperature of 700℃ for 30s under pure nitrogen protection. The PL measurement shows that the band gap blueshift is influenced by the depth of ion implantation. The blueshift of the upper well which is closer to the implanted wcancies is enhanced with the ion dose faster than that from a lower well under the lower dose implantation （〈 5 × 10^11/cm^2）. When the ion dose is over 10^12/cm^2, the band gap blueshift from both the wells increases with the ion dose and finally the two peaks combine together as one peak, indicating that the ion implantation results in a total intermixing of both the quantum wells.     

离子注入/辐照引起Al2O3单晶的改性研究

600K温度下用110keV的He^＋,Ne^＋,Ar^＋离子注入及320K温度下用230MeV的^208Pb^27＋辐照Al2O3单晶样品,研究了离子注入和辐照对Al2O3单晶样品结构和光学特性的影响。从测得的光致发光谱可以清楚地看到,所有样品在波长为375,413和450nm处出现了强的发光峰。且所有5×10^16ion／cm^2注入样品的发光峰均最强。经过高能Pb辐照后的样品,在390nm处出现了新的发光峰。透射电镜分析发现在注入氖样品100nm入射深度以内形成了高浓度的小空洞（1-2nm）,在Ne沉积区域有少量大空洞形成。傅立叶变换红外光谱分析发现,波数在460-510cm^-1间的振动吸收带经过离子辐照后展宽,随着辐照量的增大,该振动吸收强度显著减弱。1000—1300cm^-1对应Al-O-Al桥氧伸缩振动模式的吸收带,辐照后向高波数方向移动。对离子注入和辐照对Al2O3单晶样品结构损伤机理进行了初步探讨。Single crystal sapphire （Al2O3 ） samples were implanted at 600 K by He, Ne and Ar ions with energy of 110 keV to doses ranging from 5 × 10^16 to 2× 10^17 ion/cm^2 or irradiated at 320 K by ^208Pb^27＋ ion with energy of 1.1 MeV/u to the fluences ranging from 1 × 10^12 to 5 × 10^14 ion/cm^2. The modification of structure and optical properties induced by ion implantation or irradiation were analyzed by using photoluminescence（PL） and Fourier transformation infrared spectrum（FIR） spectra and transmission electron microscopy（ TEM ） measurements. The PL measurements showed that absorption peaks located at 375,413 and 450 nm appeared in all the implanted or irradiated samples, the PL intensities reached up to the maximum for the 5 × 10^16 ion/cm^2 implanted samples. After Pb-ion irradiation, a new peak located at 390 nm formed. TEM analyses showed that small size voids,（ 1--2 nm） with high density were formed in the region from the surface till to about 100 nm in depth and also large size Nebubble formed in the Ne-doped region. From the obtained FTIR spectra, it was found that Pb-ion irradiation induced broadening of the absorption band in 460-510 cm^-1 and position shift of the absorption band in 1 000- 1 300 cm^- 1 towards to high wavenumber. The possible damage mechanism in single crystal sapphire induced by energetic ion implantation or irradiation was briefly discussed.     

Structural Distortion and Defects in Ti_3AlC_2 irradiated by Fe and He Ions

Ti_3AlC_2 samples are irradiated in advance by 3.5 MeV Fe-ion to the fluence of 1.0×10~(16) ion/cm~2,and then are implanted by 500 keV He-ion with the fluence of 1.0×10~(17) ion/cm~2 at room temperature.The irradiated samples are investigated by grazing incidence x-ray diffraction(GIXRD) and transmission electron microscopy(TEM).GIXRD results show serious structural distortion,but without amorphization in the irradiated samples.Fe-ion irradiation and He-ion implantation create much more serious structural distortion than single Fe-ion irradiation.TEM results reveal that there are a large number of defect clusters in the damage region,and dense spherical He bubbles appear in the He depositional region.It seems that the pre-damage does not influence the growth of He bubbles,but He-ion implantation influences the pre-created defect configurations.     

重离子束注入与生物体的相互作用及遗传诱变的分子机制

低能重离子与生物体系相互作用及其生物诱变效应的应用研究在我国率先兴起， 并在应用中取得了很大的成就。 介绍了重离子注入与生物有机体的相互作用及其主要的生物学效应， 包括细胞染色体水平、 生理生化效应， 以及对DNA损伤修复、 基因表达、 甲基化修饰的影响。 总结了离子注入诱变的分子遗传学机理的相关研究。 同时分析、 比较讨论了高能与低能离子、 离子束与射线的生物学效应的异同。 提出了离子注入今后的研究方向， 特别指出了离子注入对生物基因表达影响研究的重要性。 As a new mutagenesis technique, low energy heavy ion implantation started in China for the study of interaction effect between incident ions and organism, and great achievements have been obtained in crop breeding. The article reviewed the main biological effects induced by heavy ion implantation, including physiology, biochemistry and genetics effects, on levels of cell and chromosome, gene expression, DNA methylation, DNA damage and reparation etc. It compared the differences in mutagenesis for organism by high energy and low energy ion implantation, as well as γ ray radiaiton. Future investigation topics were proposed, the emphasis of researches in future was pointed out, i.e., the molecular mechanism and effects of gene differential expression of organism treated by ion implantation.     

Ionoluminescence Spectra of a ZnO Single Crystal Irradiated with 2.5 MeV H~+ Ions

The ionoluminescenee(IL) spectra of a ZnO single crystal irradiated with 2.5 MeVH~+ ions reveal that its intensity decreases with increasing the ion fluence, which indicates that the concentration of lumineseence centers decreases with irradiation. The Gaussian decomposition results of the ZnO IL spectrum with a fluence of1.77×10~(11) ions/cm~2 show that the spectrum is a superposition of energy levels centered at 1.75 eV, 2.10 eV, 3.12 eV and 3.20 eV. The four peaks are associated with electronic transitions from CB to V_(Zn), CB to O_i,Zn_i to VB and the decay of self-trapped excitons, respectively. The results of single-exponential fitting demonstrate that different luminescent centers have different radiation resistance, which may explain why the emission decreases more slowly in the NBE band than in the DBE band. The agglomeration of larger point clusters accounts for the decrease in the concentration of luminescence centers and the increase in the concentration of non-luminescence centers, which indicates that the defect clusters induced by ion implantation act as nonradiative recombination centers and suppress light emission. The results of the photoluminescence spectra of a virgin ZnO single crystal and a ZnO single crystal irradiated with a fluence of 3.4 x 1014 ions/cm~2 show that compared with the virgin ZnO,the emission intensity of irradiated ZnO decreases by nearly two orders of magnitude, which demonstrates that the irradiation effect reduces radiative recombination and enhances nonradiative recombination. The conclusions of photoluminescence are consistent with the IL results.     

N离子注入对Ti—Al—Zr合金耐蚀性影响研究

经完全退火处理的Ti-Al-Zr合金表面注入不同剂量的N离子,并在pH值为10的溶液中进行电化学腐蚀试验。结果表明,N离子注入后,试样表面首先形成具有四方结构的ε-Ti2N,随着离子注入剂量的增加,四方结构的ε-Ti2N逐渐向立方结构的σ-TiN转变,X射线光电子能谱的分析结果也证实了这一变化过程;N离子的注入能明显改善Ti-Al-Zr合金表面的耐腐蚀性能,且在注入8×10^16 ion／cm^2时得到最佳的耐腐蚀性。根据原子碰撞理论对电化学腐蚀实验结果进行了理论分析。In the present investigation, fully annealed Ti-Al-Zr plates were implanted with different nitrogen fluences. The corrosion resistance was examined by the electrochemical methods in a solution with pH value of 10 at room temperature in order to determine the optimum fluenee that can give good corrosion resistance in a simulated nuclear reactor condition. The results show ε-Ti2N phase formed initially and then transformed into σ-TIN with increasing of nitrogen fluences, which was confirmed by the results of X-ray photoelectron spectroscopy （XPS）. In addition, it can be found the increase of the corrosion resistance depends on the nitrogen fluence employed and the maximum improvement of the corrosion resistance was observed with a fluence of 8 × 10^16 N^＋ ion/cm^2. The mechanism of the corrosion resistance is attributed to defect accumulation, formatio on of amorphous phase and nanocrystallization in the implanted layer.     

模拟微重力效应对辐射致细胞DNA损伤修复效应的影响

在地面模拟微重力的情况下, 应用碱性单细胞凝胶电泳（SCGE）技术对80 MeV/u Ne离子辐射诱发人血淋巴细胞DNA损伤修复效应进行了研究。 在不同时刻对相同剂量辐照后的淋巴细胞经单细胞电泳处理后显示, 在模拟微重力下孵育的彗星尾更长, 彗星头面积更小。 这表明, 相对地面环境而言, 模拟微重力环境对淋巴细胞的DNA损伤修复有一定的抑制作用。 Effect of the modeled microgravity (MMG) on heavy ion induced lymphocytes DNA repair by using single cell gel electrophoresis (SCGE) has been studied. The results showed that residual DNA damage induced by Ne ions irradiation increased more in cultures incubated in MMG than in 1 g, which indicated that MMG incubation after Ne ions irradiation reduce the DNA damage repair capacity.     

离子注入对黑松花粉粒和花粉管内骨架系统的损伤效应

以黑松花粉粒和花粉管为试验材料, 研究了离子注入对细胞骨架系统的损伤效应。研究结果表明, 离子注入会不同程度地破坏花粉管内微管网络的完整性, 花粉管形态的异常状态与其微管骨架结构的异常状态密切相关。离子注入对黑松花粉管内的微管骨架系统的正常结构有明显的效应, 这种效应的明显程度与离子注入剂量有一定的相关性, 即随着离子注入剂量的增加, 微管骨架系统受到破坏的程度更加明显。离子注入对黑松花粉管内微丝骨架系统的分布状态有明显的影响, 其程度也与离子注入剂量的大小存在一定的相关性。     

离子注入结合离子交换技术制备KTiOPO4光波导特性研究

用离子注入结合离子交换技术形成了 KTiOPO₄ 平面光波导,研究了离子注入对离子交换波导结构的影响.使用棱镜耦合法测量了波导特性,结果显示形成了表面折射率升高的多模波导,通过背散射技术研究了离子交换后的 Rb 离子分布.实验表明,注入离子导致样品晶格损伤,在 2.8 μm处对离子交换形成了阻挡层,阻止了交换向KTP晶体的更深处进行.     

Measurement of lattice damage caused by ion-implantation doping of semiconductors†

Two new techniques have been used to measure the lattice damage produced in gallium arsenide by the implantation of 60 keV cadmium ions. In one of these methods, optical reflection spectra of the ion-implanted samples were measured in the wavelength range from 2000 to 4600Å. The decrease in reflectivity resulting from ion- implantation was used to determine the relative amount of lattice damage as a function of ion dose. The second technique employed the scanning electron microscope. Patterns very similar in appearance to Kikuchi electron diffraction patterns are obtained when the secondary and/or backscattered electron intensity is displayed in the scanning electron microscope as a function of the angle of incidence of the electron beam on a single crystal surface. The degradation of these ‘Coates-Kikuchi’ patterns resulting from ion implantation was used to obtain a quantitative measure of the lattice damage caused by the implantation process. The results of measurements made by both of the methods described have been compared with each other, and with data obtained by the more established method of measuring lattice damage by Rutherford scattering of 1 MeV helium ions.     

用拉曼光谱测量离子注入引起的晶格应变

 对于10个周期的AlAs/GaAs超晶格和25个周期的GaAs/Ga0.92In0.08As超晶格,在室温下进行0.28 MeV的Zn＋注入,注入剂量为5×10¹³~5×10¹⁴ cm^-2。通过拉曼光谱测量,定量地分析了由于离子注入所引起的晶格内应变。实验结果表明：在所选用的注入剂量下,由于离子注入引起的应变小于体材料GaAs的最大非驰豫应变值0.038,说明该注入条件下,注入区的结晶态仍然保持得比较好。在较高注入剂量下应变达到饱和,说明缺陷的产生和复合达到了平衡,从而形成了均衡的应变场分布。     

Surface defects,stress evolution,and laser damage enhancement mechanism of fused silica under oxygen-enriched condition

Oxygen ions (O⁺) were implanted into fused silica at a fixed fluence of 1×10¹⁷ ions/cm² with different ion energies ranging from 10 keV to 60 keV. The surface roughness, optical properties, mechanical properties and laser damage performance of fused silica were investigated to understand the effect of oxygen ion implantation on laser damage resistance of fused silica. The ion implantation accompanied with sputtering effect can passivate the sub-/surface defects to reduce the surface roughness and improve the surface quality slightly. The implanted oxygen ions can combine with the structural defects (ODCs and E' centers) to reduce the defect densities and compensate the loss of oxygen in fused silica surface under laser irradiation. Furthermore, oxygen ion implantation can reduce the Si-O-Si bond angle and densify the surface structure, thus introducing compressive stress in the surface to strengthen the surface of fused silica. Therefore, the laser induced damage threshold of fused silica increases and the damage growth coefficient decreases when ion energy up to 30 keV. However, at higher ion energy, the sputtering effect is weakened and implantation becomes dominant, which leads to the surface roughness increase slightly. In addition, excessive energy aggravates the breaking of Si-O bonds. At the same time, the density of structural defects increases and the compressive stress decreases. These will degrade the laser laser-damage resistance of fused silica. The results indicate that oxygen ion implantation with appropriate ion energy is helpful to improve the damage resistance capability of fused silica components.     

Ion implantation in IV–VI semiconductors

In this review, ion-implantation doping and ion-implantation damage in IV–VI semiconductors are discussed. Doping can be achieved by implanting impurity atoms as well as the constituent elements themselves since the electrical properties of these compounds are determined not only by impurities but also by deviations from stoichiometry. Results obtained with implantation doping are presented and the applications of ion implantation to the fabrication of infrared photodetectors and laser diodes are summarized. The main feature of the implantation damage is a saturation of the carrier concentration as a function of the dose, independent of the ion species and implantation conditions. This unusual behaviour has been explained recently by a defect-level model, which is discussed in detail. The similarity of the damage caused by ion implantation and by electron irradiation is pointed out.     

Micro-Raman and ion channeling study of crystal damage in Si induced by focused Co ion beam implantation

The lattice damage of silicon produced by ion implantation at extremely high current density of 0.8 A/cm² (2.5᎒¹⁸ cm^-2 s^-1) was investigated. In a focused ion beam system, implantation was carried out with 70 keV Co ions, fluences of 1.2᎒¹⁶ cm^-2 and 6.7᎒¹⁵ cm^-2 into Si (111) at room temperature and elevated temperatures between 355 °C and 400 °C. Radiation damage measurements were performed by Rutherford backscattering/channeling spectroscopy and micro-Raman analysis. The radiation damage was studied as a function of pixel dwell-time and implantation temperature. The critical temperature for amorphization increases with current density. Although the fluence of the focused ion implantation was constant, crystalline layers were obtained for short and amorphous layers for long pixel dwell-times. The critical dwell-time of crystalline/amorphous transition increases with implantation temperature. From the results a typical time for defect annealing of 10^-5 s at 400 °C and an activation energy of (2.5ǂ.6) eV were deduced.     

用掩蔽注入法研究钛注入H13钢的耐磨性

采用由金属蒸汽真空弧离子源引出的强束流钛、碳离子对H13钢进行表面改性研究.钛和碳离子注入剂量分别为3×1017和1×1017cm-2,引出电压分别为48和30kV，平均束流密度分别为47和20μA·cm-2.为了保持相同的摩擦磨损实验条件，注 入过程中采用掩蔽注入技术.摩擦磨损实验结果表明，钛离子注入H13钢提高了其耐磨性，并大幅度降低其摩擦系数.利用卢瑟福背散射谱测量了离子注入表面的成分，并采用逐层递推 法得出了钛在H13钢中的浓度深度分布，借助掠面x射线衍射考察了注入表面的相结构. 关键词： 钛离子注入 金属蒸汽真空弧 卢瑟福背散射 掠面x射线衍射