自离子辐照对兆伏注P+硅中二次缺陷的影响

用平面透射电子显微术和剖面透射电子显微术以及卢瑟福背散射沟道谱技术研究了兆伏注P⁺硅中的二次缺陷以及自离子辐照对它们的影响.实验结果表明，二次缺陷峰的深度稍大于平均投影射程.实验还发现，用适当能量和剂量的自离子在退火之前辐照兆伏注P⁺硅样品，可以抑制二次缺陷的生成，但如果在退火之后辐照，则会得到相反效果.对此现象的物理原因进行了讨论.另外，还给出了Si⁺，P⁺在硅中形成二次缺陷带的临界剂量，并且对临界剂量与注入能量的关 关键词：     

低剂量磷离子注入快速退火硅中的缺陷研究

本文对低剂量磷离子注入硅经快速热退火后的缺陷特性进行研究。600℃退火就能基本激活注入离子。800℃以下退火样品中的缺陷主要是离子注入形成的辐射损伤缺陷。800℃以上退火样品中存在位错缺陷。位错的形成与离子注入引进的损伤和淬火过程中的热应力有关。1100℃退火样品中的缺陷浓度迅速增大,热应力在硅内部产生大量的滑移位错。 关键词：     

基于水解活性的Zn2+荧光探针

合成了一种新颖的锌离子荧光探针N’(2-羟基苄基)-4-(2-羟基苯亚甲基胺)-苯甲酰肼(HHB),该探针本身的荧光较弱,但当它与Zn²⁺配位时荧光增强,在475 nm处产生一较宽的发射光谱,量子产率f=0.59 (λ_ex=370 nm)。该化合物对Zn²⁺具有良好的选择性能,环境生物体系中大量存在的碱金属和碱土金属离子K⁺,Na⁺,Mg²⁺和Ca²⁺以及过渡金属离子Mn²⁺,Co²⁺,Ni²⁺ 和 Cu²⁺ 等对Zn²⁺的检测没有明显影响。在生命体系的pH值范围(6.8~7.7),配合物HHB显示出对Zn²⁺检测较高的灵敏度。作为比较文中还研究了HHB水解的主要产物4-氨基苄腙-水杨醛(HB)对Zn²⁺的识别与传感性能。     

MeV高能B+离子注入Si中二次缺陷的抑制与消除

本文研究了MeV高能B⁺离子注入Si中二次缺陷的退火行为。提出一种新型的双重注入退火方法,抑制或消除了MeV高能B⁺离子注入Si样品中的二次缺陷。还对这种二次缺陷的被抑制与被消除的物理机制进行了讨论。 关键词：     

B+注入HgCdTe快速热退火的研究

借助二次离子质谱和俄歇电子能谱对B⁺注入HgCdTe有无ZnS膜包封在快速热退火条件下表层的Hg损失进行了深入的分析-快速热退火温度为300，350和400℃，退火时间为10s-ZnS膜厚度为160nm-结果表明，300℃，10s快速热退火后，有ZnS膜包封的HgCdTe表层没有Hg损失-对B⁺注入HgCdTe N⁺-P结快速热退火工艺流程进行了优化-结果表明，快速热退火放在光刻金属电极之后进行，可以改善结的特性- 关键词：     

聚变材料钨辐照后退火形成的位错环特性及inside-outside衬度分析

对纯钨透射电镜薄膜样品在400℃进行了58 keV、1×10¹⁷ cm^-2(约0.1 dpa)的氘离子辐照,辐照后进行了900℃/1 h的退火处理.离子辐照产生了平均尺寸为(11.10±5.41)nm,体密度约为2.40×10²² m^-3的细小位错环组织,未观察到明显的空洞组织.辐照后退火造成了位错环尺寸的长大和体密度的下降,分别为(18.25±16.92) nm和1.19×10²² m^-3.通过透射电镜的衍射衬度分析,判断辐照后退火样品中的位错环主要为a/2<111>类型位错环.通过“一步法” inside-outside衬度分析判断位错环为间隙型位错环.辐照后退火还造成了较大位错环之间接触融合,形成不规则形状的大型位错环.此外,退火后样品中还观察到了尺寸为1—2 nm的细小空洞组织.     

预注入对Si1-xCx合金形成的影响

室温下在单晶Si中注入(0.6—1.5)at%的C原子,部分样品在C离子注入之前在其中注入²⁹Si⁺离子产生损伤,然后在相同条件下利用高温退火固相外延了Si_1-xC_x合金,研究了预注入对Si_1-xC_x合金形成的影响.如果注入C离子的剂量小于引起Si非晶化的剂量,在950℃退火过程中注入产生的损伤缺陷容易与C原子结合形成缺陷团簇,难于形成Si_1-xC关键词： 离子注入 固相外延 1-xC_x合金')" href="#">Si_1-xC_x合金     

掺Er/Er+O的GaN薄膜光学性质的研究

利用Raman散射谱研究了GaN注Er以及Er+O共注样品的振动模，并讨论了共注入O对Er离子发光的影响. 在Raman散射谱中，对于注Er的GaN样品出现了300 cm^-1和670 cm^-1两个新的Raman峰，而对于Er+O共注样品，除了上述两个峰外，在360 cm^-1处出现了另外一个新的峰，其中300 cm^-1峰可以用disorder-activated Raman scattering (DARS)来解释，670 cm^-1峰是由于与N空位相关的缺陷引起的，而360 cm^-1峰是由O注入引起的缺陷络合物产生的. 由于360 cm^-1模的缺陷出现，从而导致Er+O共注入GaN薄膜红外光致发光(PL)强度的下降. 关键词： GaN Er Raman散射 光致发光     

高价离子对层状结构阴极的插入研究

研究了高价Mg²⁺,Zn²⁺等离子对层状结构阴极如V₂O₅,MoS₂,等的固态电化学插入。用X射线衍射(XRD),电子探针微区分析(EMP),电子自旋共振(ESR)和X射线光电子能谱(XPS)等物理方法研究了相应高价离子对层状阴极插入引起的相变及其插入化合物,对高价离子的插入机理进行了探讨。 关键词：     

BF+2注入多晶硅栅F迁移特性的分析与模拟

在深入分析BF⁺₂注入多晶硅栅F在多晶硅栅中迁移特性的基础上，建立了F在多晶硅栅中的迁移方程.采用有限差分法，模拟了BF⁺₂注入多晶硅栅F在多晶硅栅中的分布.模拟结果与二次离子质谱(SIMS)分析结果相符.给出了80keV，2×10¹⁵cm^-2 BF⁺₂注入多晶硅栅900℃，30min退火条件下F在多晶硅中的发射系数e=6×10关键词：     

Ions and atoms in superfluid helium (4He)

New experimental results for mobilities in superfluid helium of the alkali earth ions Be⁺, Mg⁺, Ca⁺, Sr⁺ and Ba⁺ in the temperature region from 1.27 up to 1.66 K are reported. Surprisingly, the temperature dependence of the Be⁺ ion mobility, measured here for the first time, is more similar to that of the He⁺ ion than to the heavier alkali earth ions. This behavior may suggest a snowball like structure for the defect around Be⁺ in contrast to the bubble like defects around the heavier alkali earth ions.     

Electron beam induced current investigation of planar photodiode structures on InSb crystals

Multielement planar photodiode structures produced on InSb crystals using Be⁺ ion implantation to form a p ⁺-n junction and anodic oxidation to protect the surface are studied in the Electron Beam Induced Current (EBIC) mode. It is found that the initial crystal doping level affects the EBIC distribution across the crystal surface outside the planar boundaries of the p ⁺-n junction. It is shown that the most perfect p ⁺-n junctions are formed on crystals with the highest resistivity when the lowest values of the implantation energy and dose are applied and pulse photon postimplantation annealing is used. The diffusion lengths in all the types of the structures in study are estimated. It is found that the level of anodic oxide charging by the electron beam depends on the electrolyte composition used in the anodic treatment.     

磷离子注入速率对4H-SiC(0001)晶格恢复与电阻率降低的影响

高剂量的磷离子注入4H-SiC(0001)晶面，注入速率从1.0×1012到4.0×1012 P+ cm-2s-1变化，而注入剂量固定为2.0×1015 P+ cm-2。室温注入，1500oC的高温下退火。利用光荧光和拉曼谱分析注入产生的晶格损伤以及退火后的残余缺陷。通过霍耳测试来分析注入层的电学性质。基于上述测试结果，发现通过减小磷离子的注入速率，极大地减少了注入层的损伤及缺陷。考虑到室温注入以及相对较低的退火温度(1500 oC)，在注入速率为1.0×1012 P+ cm-2s-1及施主浓度下为4.4×1019 cm-3的条件下，获得了非常低的方块电阻106 Ω/sq。     

Electrical properties of Cd,Zn and S ion-implanted layers in GaAs

The electrical properties of cadmium, zinc, and sulfur ion-implanted layers in gallium arsenide have been measured by the van der Pauw-Hall technique. Ion implantation was performed with the substrates held at room temperature. The dependence of sheet resistivity, surface carrier concentration, and mobility on ion dose and on post-implantation anneal temperature was determined. In the case of 60 keV Cd⁺ ions implanted into n-type substrates, a measurable p-type layer resulted when samples were annealed for 10 minutes at a temperature in the range 600—900°C. After annealing at 300—900°C for 10 minutes, 100 per cent electrical activity of the Cd ions resulted for ion doses ≤ 10¹⁴/cm².

The properties of p-type layers produced by implantation of 85 keV Zn⁺ ions were similar to those of the 60 keV cadmium-implanted layers, in that no measurable p-type behavior was observed in samples annealed below a relatively high temperature. However, in samples implanted with 20 keV Zn⁺ ions a p-type layer was observed after annealing for 10 minutes at temperatures as low as 300°C.

Implantation of sulfur ions into p-type GaAs substrates at room temperature resulted in the formation of a high resistivity n-type layer, evcn before any annealing was performed. Annealing at temperatures up to 200°C or above 600°C lowered the resistivity of the layer, while annealing in the range 300—500°C eliminated the n-type layer.     

Reduction of the annealing temperature of radiation-induced defects in ion-implanted MOS structures

Si-SiO₂ structures irradiated with 11-MeV electrons for 10 s and then implanted with B⁺ ions with an energy of 10 keV at a dose of 1.0×10¹² cm^-2 through the oxide were annealed at different temperatures. MOS capacitors including such oxide layers were studied by quasi-static C/V and thermally stimulated current (TSC) methods. A comparison of the radiation defect annealing of double-treated (electron-irradiated and ion-implanted) samples and of implanted-only samples was carried out. It is shown that a preceding low-dose high-energy electron irradiation of the samples leads to a lowering of the annealing temperature of radiation defects introduced by ion implantation. After annealing at 500 °C for 15 min, no TSC spectra for the double-treated samples were observed. The spectra of the other samples (which were not previously irradiated) showed that after the same thermal treatment only some of the radiation defects introduced by ion implantation are annealed. The difference between the annealed interface state density of previously electron-irradiated and current MOS structures is also demonstrated. A possible explanation of the results is proposed . PACS 61.82.Fk; 85.40.Ry; 61.80.Fe     

Flash – lamp annealing of phosphorus and antimony implanted silicon

The structure and electrophysical properties of a silicon layers after P⁺ and Sb⁺ ion implantation and subsequent pulse annealing of millisecond lengths have been investigated by the transmission electron microscopy and four-point probe measurements. It has been demonstrated, that for certain implantation and annealing conditions the epitaxially grown layers can involve the microtwins and dislocation loops. The impurity redistribution under the pulse annealing depends on the implantation dose and rather weaker the light irradiation energy density.     

Density functional investigation of metal encapsulated X@C12Si8 heterofullerene (X=Li, Na, K, Be, Mg, Ca, Al, Ga)

The stability and the possible application of our recently reported SiC heterofullerenes inspire the investigation of their further stabilization through ion encapsulation. The endohedral complexes X@C₁₂Si₈, where X=Li⁺, Na⁺, K⁺, Be²⁺, Mg²⁺, Ca²⁺, Al³⁺, and Ga³⁺, are probed at the MPWB1K/6-311G? and B3LYP/6-311G* levels of theory. The optimized geometries show the expanding or contracting capability of C₁₂Si₈ in order to accommodate metal ion guests. The inclusion energies indicate the stability of the complexes compared to the components. Meanwhile, the calculated binding energies show the stabilization of C₁₂Si₈ through the inclusion of Be²⁺, Mg²⁺, Al³⁺, and Ga³⁺. The host-guest interaction that is probed through NBO atomic charges supports the obtained results. This study refers to “metal ion encapsulation” as a strategy for stabilization of SiC heterofullerenes.     

Secondary-ion emission from oxygen and hydrogen-covered beryllium surfaces: I. Coverage dependence

Secondary ion emission from a beryllium surface is studied in the presence of hydrogen and oxygen. For submonolayer coverages of oxygen, the adsorption follows site-exclusion statistics. On this basis, the Be⁺ secondary ion yield and energy distribution can be separated into oxygen-dependent and oxygen-independent processes governed by the local properties of the surface. Ionic molecular species with hydrogen or oxygen present include Be₂O⁺, Be₂O^?, BeO^?, and BeH⁺ but not BeO⁺ or BeOH⁺. This result is inconsistent with emission in which the oxide molecule is formed in the near-surface vacuum region by agglomeration of individually sputtered surface atoms. For BeH⁺emission the opposite conclusion is reached.     

Structure modifications in AS+−ION implanted silicon layers during pulse thermal treatment

Abstract

The silicon layers structure after As⁺?ion implantation and subsequent pulse annealings, which were carried out in nanosecond (Q-switched ruby laser) or/and few seconds (halogen lamps) time intervals, has been studied by transmission electron microscopy techniques. It has been shawn that the structure state is determined to a large extend by pulse annealing parameters. In the case of second pulse annealing the level of ion-implanted layer disordering affects considerably the obtained structure.     

Thermal annealing induced photocarrier radiometry enhancement for ion implanted silicon wafers

An experimental study on the photocarrier radiometry signals of As⁺ ion implanted silicon wafers before and after rapid thermal annealing is performed. The dependences of photocarrier radiometry amplitude on ion implantation dose (1×10¹¹--1×10¹⁶/cm²), implantation energy (20--140 keV) and subsequent isochronical annealing temperature (500--1100 du are investigated. The results show that photocarrier radiometry signals are greatly enhanced for implanted samples annealed at high temperature, especially for those with a high implantation dose. The reduced surface recombination rate resulting from a high built-in electric field generated by annealing-activated impurities in the pn junction is believed to be responsible for the photocarrier radiometry signal enhancement. Photocarrier radiometry is contactless and can therefore be used as an effective in-line tool for the thermal annealing process monitoring of the ion-implanted wafers in semiconductor industries.