金刚石砂轮磨削单晶硅片面形变化规律

磨削减薄过程中,硅片表面产生亚表面损伤,其中的残余应力使硅片产生翘曲变形。因此,研究无光磨磨削时的硅片面形变化规律以评价其加工质量。使用金刚石砂轮无光磨磨削厚度400μm和450μm的硅片并测量其面形。将硅片面形数据从中心向边缘沿径向分割成5个环带,分别研究其面形拟合弯曲曲率半径变化。结果显示:从中心区域到边缘区域,硅片的变形量增大,说明无光磨硅片上的残余应力变大,即磨削加工损伤增大。同时,研究还发现晶向对硅片变形有显著影响,〈110〉晶向区变形与〈100〉晶向区变形差异明显。      

面阵列封装互连结构热循环翘曲变形抗力

借助有限元软件对钎料球、钎料柱和铜柱阵列互连结构热循环载荷下的翘曲变形行为进行研究. 结果表明，三者升温过程均表现为刚度低的树脂基板呈下凹变形、而降温至0 ℃后呈现上凸变形，变形规律相同. 不同温度下两端基板的热膨胀系数差异引发的基板内及相连焊球/焊柱内的应力及力矩是翘曲变形发生的驱动力. 两焊柱阵列互连的基板翘曲位移接近，但均明显低于焊球阵列的基板，翘曲变形抗力更大. –40~125 ℃热循环温度范围及基板尺寸条件下，铜柱未屈服，相对钎料柱阵列互连，未表现铜柱可挠曲变形释放应力的优势.     

Photoluminescence Properties of Porous Silicon Based on FZ(H) Si Wafer

1 IntroductionThe visible ltiminescence at room temperatUre of porous silicon (PS) has been attractivefor the pmpose of using it in Photo-electronicdevices. The large stirface area of PS has focused attentions not only on surface modificationdirected toward coevalling Photo-electronicProperties but also on new exciting applicationsin the sensors and biomaterials areas [l]. For thesolid-state contact, semitranspared conductingmaterials have been formed on PS by Physical orchemical vapor dep…     

基于Moldflow塑料薄壳制品翘曲变形分析

在分析翘曲变形理论基础上,用有限元法研究了冷却温度、收缩率、分子取向因素等对薄壳制品翘曲变形的影响,以复印机外壳为例,给出它的CAE分析步骤,研究塑件沿X、Y、Z方向的变形量,并给出相应的改进措施。研究表明:选择的工艺参数对塑件不同方向上的翘曲变形有不同程度的影响,优化工艺参数组合可使塑件翘曲变形量达到最小,从而提高塑件质量,优化模具结构。     

Amorphous Ni-Mo-P diffusion barrier deposited by non-isothermal deposition

Ni-Mo-P barrier layers deposited on silicon wafers without Pd activation pretreatment were prepared using the non-isothermal deposition (NITD) method in an acidic electroless bath. The operating conditions for fabricating the Ni-Mo-P barrier layers were presented, and the effect of the pH values on the film composition, electric resistivity and thermal stability have been investigated. The thicknesses of Ni-Mo-P films are around 15-20 nm in acidic bath. Our results indicate increasing amounts of Mo and decreasing amounts of P with increasing pH. The electric resistivity decreased with increasing pH value due to the increase of the Mo content in the Ni-Mo-P film. The amorphous structure was formed at pH 3 and 4, but a quasi-amorphous structure was formed at pH 5. Based on our experimental results, the thermal stability of Ni-Mo-P film prepared at pH 4 remains stable up to 650 °C for 1 h annealing.     

A grinding-based manufacturing method for silicon wafers: an experimental investigation

The majority of semiconductors are built on silicon wafers. Future semiconductors will require flatter wafers with a lower price. The lapping-based manufacturing method currently used to manufacture silicon wafers will not be able to meet the ever-increasing demand cost-effectively. This paper reports an experimental investigation into a grinding-based manufacturing method, which has potential to manufacture flat silicon wafers at a lower cost. Background information on semiconductors and silicon wafers is presented first. After a discussion on drawbacks of the lapping-based method, the grinding-based method is described. Next, experimental results with the grinding-based method are presented and discussed. The results from this investigation have demonstrated the potential of the grinding-based method and revealed several directions for future work.     

预退火对Fe73.5Cu1Mo3Si13.5B9非晶合金的晶化及磁性的影响

本文研究了预退火温度和时间对Ｆｅ(７３．５)Ｃｕ１Ｍｏ３Ｓｉ(１３．５)Ｂ９非晶合金在最后退火过程中发生的 晶化及软磁性能的影响。结果表明：在较低温度下预退火能有效地控制合金的晶化过程,降低了最 后退火时所放出的晶化潜热。该合金在４５０℃进行１ｈ预退火发生部分晶化,释放约３２％的晶化 潜热,再经５１０℃保温１ｈ最后退火其磁性能与制备态样品经５１０℃退火后的磁性能相比,最大磁 导率ｍ显著提高,矫顽力Ｈｃ明显下降,Ｂｓ和Ｂｒ无明显变化。     

Dislocation density simulations for bulk single crystal growth process

Computer simulations of the dislocation density during Czochralski (CZ) single crystal growth were performed for silicon crystals with 8-inch or 10-inch diameter using a finite element computer code developed by the authors. In the computer code, a dislocation kinetics model called the Haasen-Sumino model was used for the constitutive equation of a crystal at elevated temperatures. The computer code provides the dislocation density distributions and stress distributions during the CZ growth process. In the simulations, two values for the Young’s modulus for the silicon single crystal were used in order to examine the effect of the Young’s modulus on the dislocation density.     

热暴露对新型铝基活塞合金组织和性能的影响

研究了Al-Si-Cu-Mg-Ni新型活塞合金经过固溶时效热处理后,再在350℃热暴露不同时间(0～1 000 h)后的显微组织和性能.结果表明:随着暴露时间的延长,合金的室温和高温剩余强度明显下降,在0～10h,强度降低较快,10h后,合金的室温和高温抗拉强度基本稳定在209 MPa和51 MPa;随着暴露时间的延长,合金的伸长率明显提高,在0～1 00 h,伸长率显著提高,100 h后,其室温和高温伸长率基本稳定在2.8％和8.9％.随着热暴露时间延长,热处理组织中的块状初生硅无明显变化,粒状共晶硅长大并粗化,均匀地分布于基体中,Q和θ相长大并粗化.     

Comparison of measurements and simulation results in 300 mm CZ silicon crystal growth

A special thermal modeling tool, CrysVUn, which was developed by Crystal Growth Laboratory (CGL) of Fraunhofer Institute of Integrated Systems and Devices Technology in Erlangen of Germany, was used for numerical analysis of growth interface situation. The heat transportation, argon flow and melt convection have been considered. Cauchy's first and second laws of motion have been the governing partial equations for stress calculation. The measurement results and simulation results were compared and the interface shape and thermal stress distribution during 300 mm Czochralski (CZ) silicon crystal growth with different growth rates were predicted.     

Metal film crawling in interconnect structures caused by cyclic temperatures

Thermal cycling is widely used as a qualification test in the microelectronic industry. This paper investigates an intriguing failure mode observed in such a test. Near the corners of a silicon die, shear stresses arise due to thermal expansion mismatch between the silicon and the packaging substrate. These shear stresses may have a small magnitude, being transmitted through packaging polymers, but sometimes motivate metallic interconnect films to crawl toward the center of the die during thermal cycling, even when the temperatures are low and the metal creeps negligibly. The phenomenon has been observed for two decades, but no mechanistic explanation has been given so far. This paper shows that the metal films can crawl by ratcheting plastic deformation. When the temperature cycles, the thermal expansion mismatch between the silicon and the metal causes the metal films to yield. Directed by the small shear stresses, the films shear plastically by a small amount in each cycle, and accumulate a large deformation after many cycles. We develop an idealized model to demonstrate this mechanism, and to study the effects of temperature-dependent yield strength and strain hardening. Several analytical solutions are obtained. Implications for the qualification test and interconnect design are discussed. The study clearly shows the need for basic research on large plastic deformation at small length scales.     

Infrared studies of vacancy-oxygen-related complexes in electron-irradiated Czochralski-silicon

The oxygen-related defects in CZ silicon during electron irradiation (1.5 MeV) and subsequent annealing in the range of 150-600 ℃ were investigated by means of FTIR.In the electron irradiation CZ-Si, vacancy-oxygen complex is one of the dominant defects and its concentration is proportional to electron dose but not related to oxygen concentration.In this work, it was focused on the identification of the weak band at 860 cm-1 which was originated from asymmetrical stretching vibrations of an oxygen atom in the negative VO complex.It exhibits the same thermal stability with neutral VO band at 830 cm-1.In addition, the intensity of 889 cm-1 band has never been observed to exceed that of the A-center, implying that only a partial transformation of VO into VO2 does occur.     

Alloys Preparation of Ag Particles/Islands on Si Wafer by RF Magnetron Sputtering

In order to investigate the morphology change of Ag nano-particles/island film with the sputtering time and annealing temperature,Ag nano-particles/island films were sputtered on the silicon wafers by radio-frequency(RF)magnetron sputtering.Ag nano-particles/islands films were sputtered on Si wafer with different time.After sputtering,the samples with Ag nano-particles/islands films were annealed at 100,200 and 400 o C for 1 h,respectively.Raman spectrum was employed to examine the phase stability of Ag particles/island film after annealed at 400 o C for 1h.The result showed that the Raman spectrum peak of Ag particles/island film with annealed at 400 o C was similar to that of pure Ag.Scanning electron microscope(SEM)was used to test the microstructures and morphology of the films with different condition.To further study the morphology change,atomic force microscope(AFM)was used to test surface morphology of the Ag particles/islands films.The SEM and AFM results showed that the morphology of Ag nano-particles/island films were different with the increasing sputtering time.Ag particles went through a dramatic change on the Si wafer surface,when sputtering time changed from 3 to 60 s,Ag particles diffused and agglomerated with the annealing temperature increasing.     

冷轧带钢倾斜浪缺陷产生机理分析及控制研究

冷轧带钢倾斜浪缺陷即带钢表面斜纹是冷连轧产品普遍存在的一种板形缺陷,其产生机理及调控手段尚不清楚。介绍了倾斜浪缺陷的特征;进行了轧制规程调整、轧机设备精度调整等轧制试验。结果表明,双边浪轧制和调节五机架前后张力对倾斜浪缺陷有较为明显的影响。综合理论分析和试验结果,认为轧机出口带钢横断面张力不均,造成张力大的部分条元延伸率大,即造成带钢横断面的金属纵向延伸率不同,不能均匀纵向流动,且产生横向流动,各条元之间产生相互作用的内应力,当内应力足够大就会引起带钢翘曲;此条元的带钢翘曲后,张力变小,相邻条元的张力变大,带钢翘曲沿着带钢纵向斜的方向移动,便产生了倾斜浪缺陷。为此,提出了采用双边浪轧制和调整五机架前后轧制张力共同抑制倾斜浪缺陷的方法,试验结果表明倾斜浪缺陷改善明显。     

Effect of preannealing on glass transition and crystallization of gas atomized Cu47Ti33Zr11Ni8Si1 metallic glass powders

Differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used as the main method to investigate the effect of relaxation on the glass transition and crystallization of Cu₄₇Ti₃₃Zr₁₁Ni₈Si₁ metallic glass powders. The preannealing treatments were performed at temperatures close to the experimentally determined glass transition temperature. It was found that the thermal stability is profoundly affected by preannealing since the crystallization temperature is strongly influenced by preannealing and decreases with increase in preannealing temperature. In contrast, the annealing treatment does not change the glass transition temperature. During heat treatment at temperatures around the calorimetric glass transition temperature, T_g, the glassy powder undergoes microstructural alterations as revealed by TEM but not discernible by XRD. Fine nanocrystals of about 4–6 nm homogeneously dispersed in an amorphous matrix are observed by TEM after annealing at 698 K for 60 min. Kissinger analysis reveals that the preannealing decreases the activation energy for nanocrystallization thereby promoting partial crystallization of the glass.     

Abrasive electrochemical multi-wire slicing of solar silicon ingots into wafers

To meet the growing demands of the global photovoltaic (PV) industry, preparing large scale and ultra-thin solar wafers becomes one of the key issues. This paper presents the preparatory investigations of slicing solar silicon ingot into wafers by an abrasive electrochemical method based on a multi-wire saw system. The anodic passivation on silicon can be controlled by applying an anodic potential during the mechanical slicing process, which improves the surface integrity and material removal rate remarkably. This new hybrid machining method has no influence on subsequent cleaning of wafers and preparing the solar cells, and the average photoelectric transformation efficiency is >17.5%.     

地佐辛复合酮咯酸氨丁三醇超前镇痛对大鼠术后痛阈和炎性反应的影响

目的:探讨地佐辛复合酮咯酸氨丁三醇超前镇痛（preemptive analgesia,PA）对大鼠术后痛阈和炎性反应的影响。方法: 60只SD大鼠随机分为3组：对照组(N组)、超前镇痛组（CZ组）和术后镇痛组（SZ组）,每组各20只。采用腹部正中切口,开腹后无菌缝合关腹模型。各组分别在术前（0 h）,术后6 、12 、24 h各取5只大鼠,采用BL-420生物机能实验系统测定痛阈后下腔静脉采血分离血清,ELISA法测定：血清肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）和白细胞介素-1β（interleukin-1β,IL-1β）;免疫印迹法检测P物质（substance P,SP）水平。结果: 0 h三组痛阈比较差异无统计学意义（P＞0.05）,6、12 h和24 h痛阈N组显著低于CZ组和SZ组（P＜0.01）,而CZ组和SZ组比较无统计学差异（P＞0.05）;0 h N组、CZ组和SZ组TNF-α、IL-1β比较差异无统计学意义（P＞0.05）,6、12 h和24 h TNF-α、IL-1β N组显著高于CZ组和SZ组（P＜0.01）,6 h CZ组和SZ组比较无统计学差异（P＞0.05）,12 h和24 h SZ组显著高于CZ组（P＜0.01）。0 h N组、CZ组和SZ组SP比较差异无统计学意义（P＞0.05）,6、12 h和24 h SP N组显著高于CZ组和SZ组（P＜0.01）,6 h和12 h CZ组和SZ组比较无统计学差异（P＞0.05）,24 h SZ组显著高于CZ组（P＜0.01）。结论:地佐辛复合酮咯酸氨丁三醇镇痛效果确切,能够有效抑制术后炎性因子TNF-α、IL-1β和疼痛因子SP浓度的升高,且PA法效果优于术后镇痛。     

Effects of rapid thermal process on the junction properties of aluminum rear emitter solar cells

N-type silicon with aluminum emitters for rear junctions was studied; aluminum back surface fields were replaced with n-type silicon wafers. Aluminum rear emitters for n-type silicon solar cells were studied with various rapid thermal processing conditions. With fast ramping-up and fast cooling, an aluminum rear junction was formed uniformly with low emitter recombination current. The effects of junction quality on solar cell efficiency were investigated.     

Effect of preannealing on crystallization process of amorphous Sm5Fe80Cu1Si5B3C2.5Zr3.5 alloy

In the view of crystallization activation energy of amorphous alloy,the mechanism of coarse grain in annealed Sm5Fe80Cu1Si5B3C2.5ZR3.5 amorphous alloy was analyzed.It reveals the e4ffect of preannealing on the process crystallization.The results show that preannealing can be used to change the crystallization behavior of the α-Fe phase in the Sm5Fe80Cu1Si5B3C2.5Zr3.5 amorphous alloy,whick is helpful for forming α-Fe phase grains;and it is not large for Sm2Fe17Cx phase.     

NITROGEN-OXYGEN COMPLEXES IN SILICON AND THEIR DONOR ACTION

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