化学镀Ni-P在纯锡凸点的应用及界面研究

采用化学镀Ni-P作UBM阻挡层,利用电镀的方法制备了面阵列和周边排布的无铅纯锡凸点,凸点高度为85±2μm,一致性良好。研究了不同回流温度下纯锡焊球的剪切强度、断裂模式和与Ni-P层反应生成的金属间化合物。结果表明,纯锡凸点回流时与Ni-P生成针状Ni3Sn4,凸点剪切强度达到92MPa以上。剪切断裂为韧性断裂,随着回流温度提高及回流时间延长,Ni3Sn4相由针状向块状转变,Ni-P层与Ni3Sn4层间生成层状Ni3P相,粗化的Ni3Sn4相受压应力向焊球内部脱落。     

Structural and physical properties of BiFeO3 thin films epitaxially grown on SrTiO3（001） and polar（111） surfaces

The influence of surface polarity on the structural properties of BiFeO3 （BFO） thin films is investigated. BFO thin films are epitaxially grown on SrTiO3 （STO） （100） and polar （111） surfaces by oxygen plasma-assisted molecular beam epitaxy. It is shown that the crystal structure, surface morphology, and defect states of BFO films grown on STO substrates with nonpolar （001） or polar （111） surfaces perform very differently. BFO/STO （001）is a fully strained tetragonal phase with orientation relationship （001）[100]BFOII（001）[100]STO, while BFO/STO （111） is a rhombohedral phase. BFO/STO （111） has rougher surface morphology and less defect states, which results in reduced leakage current and lower dielectric loss. Moreover, BFO films on both STO （001） and STO （111） are direct band oxides with similar band gaps of 2.65 eV and 2.67 eV, respectively.     

铝阳极氧化基板制备过程对埋置型Ta-N薄膜电阻的影响

在铝阳极氧化多层基板内用RF反应溅射制备了埋置型Ta-N薄膜电阻,研究了铝阳极氧化过程对Ta-N薄膜电阻和显微结构的影响.实验结果表明:Ta-N薄膜受上层多孔氧化铝膜影响在表层形成了由Ta2O5和Ta-O-N组成的氧化物凸起绝缘层,氧化物凸起层厚度与氧化电压有关.底层Ta-N薄膜电阻率和电阻温度系数基本保持不变,表层氧化凸起使电阻稳定性增加.     

Growth and photoluminescence properties of inclined ZnO and ZnCoO thin films on SrTiO_3（110） substrates

ZnO thin film growth prefers different orientations on the etched and unetched SrTiO 3（STO）（110） substrates.Inclined ZnO and cobalt-doped ZnO（ZnCoO） thin films are grown on unetched STO（110） substrates using oxygen plasma assisted molecular beam epitaxy,with the c-axis 42 inclined from the normal STO（110） surface.The growth geometries are ZnCoO[100]//STO[110] and ZnCoO[111]//STO[001].The low temperature photoluminescence spectra of the inclined ZnO and ZnCoO films are dominated by D 0 X emissions associated with A 0 X emissions,and the characteristic emissions for the 2 E（2G）→ 4A2（4F） transition of Co 2＋ dopants and the relevant phonon-participated emissions are observed in the ZnCoO film,indicating the incorporation of Co 2＋ ions at the lattice positions of the Zn 2＋ ions.The c-axis inclined ZnCoO film shows ferromagnetic properties at room temperature.     

NGN技术应用及发展展望

NGN是目前各国电信部门都在应用的热点技术,也是电信网络的发展趋势。本文描述了NGN的技术和业务特点,分析了NGN对传统固网运营商带来的威胁和机遇,结合传统固网运营商的优势和劣势,提出了传统固网运营商的应对策略。     

铝阳极氧化基板制备过程对埋置型Ta-N薄膜电阻的影响

在铝阳极氧化多层基板内用RF反应溅射制备了埋置型Ta-N薄膜电阻,研究了铝阳极氧化过程对Ta-N薄膜电阻和显微结构的影响.实验结果表明:Ta-N薄膜受上层多孔氧化铝膜影响在表层形成了由Ta2O5和Ta-O-N组成的氧化物凸起绝缘层,氧化物凸起层厚度与氧化电压有关.底层Ta-N薄膜电阻率和电阻温度系数基本保持不变,表层氧化凸起使电阻稳定性增加.     

Growth and photoluminescence properties of inclined ZnO and ZnCoO thin films on SrTiO₃（110） substrates

ZnO thin film growth prefers different orientations on the etched and unetched SrTiO 3(STO)(110) substrates.Inclined ZnO and cobalt-doped ZnO(ZnCoO) thin films are grown on unetched STO(110) substrates using oxygen plasma assisted molecular beam epitaxy,with the c-axis 42 inclined from the normal STO(110) surface.The growth geometries are ZnCoO[100]//STO[110] and ZnCoO[111]//STO[001].The low temperature photoluminescence spectra of the inclined ZnO and ZnCoO films are dominated by D 0 X emissions associated with A 0 X emissions,and the characteristic emissions for the 2 E(2G)→ 4A2(4F) transition of Co 2+ dopants and the relevant phonon-participated emissions are observed in the ZnCoO film,indicating the incorporation of Co 2+ ions at the lattice positions of the Zn 2+ ions.The c-axis inclined ZnCoO film shows ferromagnetic properties at room temperature     

微尺寸SnAg凸点的制备技术及其互连可靠性

用电镀法制备了尺寸小于100μm的面阵列Sn-3.0Ag凸点.芯片内凸点的高度一致性约1.42%,Φ100mm硅圆片内的高度一致性约3.57%,Ag元素在凸点中分布均匀.研究了不同回流次数下SnAg/Cu的界面反应和孔洞形成机理,及其对凸点连接可靠性的影响.回流过程中SnAg与Cu之间Cu6Sn5相的生长与奥氏熟化过程相似.SnAg/Cu6Sn5界面中孔洞形成的主要原因是相转变过程中发生的体积缩减.凸点的剪切强度随着回流次数的增多而增大,且多次回流后SnAg/Cu界面仍然结合牢固.Cu6Sn5/Cu平直界面中形成的孔洞对凸点的长期可靠性构成威胁.     

Ferromagnetism,variable range hopping,and the anomalous Hall effect in epitaxial Co：ZnO thin film

A series of high quality single crystalline epitaxial Zn 0.95 Co 0.05 O thin films is prepared by molecular beam epitaxy.Superparamagnetism and ferromagnetism are observed when the donor density is manipulated in a range of 10 18 cm 3-10 20 cm 3 by changing the oxygen partial pressure during film growth.The conduction shows variable range hopping at low temperature and thermal activation conduction at high temperature.The ferromagnetism can be maintained up to room temperature.However,the anomalous Hall effect is observed only at low temperature and disappears above 160 K.This phenomenon can be attributed to the local ferromagnetism and the decreased optimal hopping distance at high temperatures.     

微尺寸SnAg凸点的制备技术及其互连可靠性

用电镀法制备了尺寸小于100μm的面阵列Sn-3.0Ag凸点.芯片内凸点的高度一致性约1.42%,Φ100mm硅圆片内的高度一致性约3.57%,Ag元素在凸点中分布均匀.研究了不同回流次数下SnAg/Cu的界面反应和孔洞形成机理,及其对凸点连接可靠性的影响.回流过程中SnAg与Cu之间Cu6Sn5相的生长与奥氏熟化过程相似.SnAg/Cu6Sn5界面中孔洞形成的主要原因是相转变过程中发生的体积缩减.凸点的剪切强度随着回流次数的增多而增大,且多次回流后SnAg/Cu界面仍然结合牢固.Cu6Sn5/Cu平直界面中形成的孔洞对凸点的长期可靠性构成威胁.