Copper Electrodeposition in ULSI

利用铜代替铝作为超大规模集成电路的互连接线 ,代表了半导体工业的重要转变。铜电沉积是互连“大马士革”( Damascene)工艺中最为重要的技术之一。综述了铜在芯片微刻槽中电沉积填充的过程、机理 ,并着重讨论了实现无裂缝和无空洞理想填充的主要因素—镀液的组成和添加剂的影响。Shift from Al to Cu interconnects in Ultra-Large Scale Integrate (ULSI) is important for semiconductor industry. Cu electrodeposition is one of the most important technologies in the Damascene fabrication of interconnects. The procedure and mechanism of copper filling in the trench of the chip are reviewed, the effect of electrolyte components and additives on superfilling are discussed

Effect of Chloride Ion on Electrocrystallization of Copper on Glass Carbon Electrode

采用线性扫描伏安法和计时安培法研究了硫酸铜溶液中铜在玻碳电极上电结晶的初期行为 .在含与不含氯离子的 0 0 5mol·L-1CuSO4 0 5mol·L-1H2 SO4电解液中 ,循环伏安实验结果表明铜在玻碳基体上的沉积没有经过UPD过程 ;氯离子明显使Cu的沉积和氧化峰变得尖锐 ,促进Cu的沉积速度 .计时安培实验结果表明 ,Cu的电结晶按瞬时成核和三维生长方式进行 .氯离子不改变Cu的电结晶机理 ,但在I～t曲线中 ,导致电流达最大 (Im)所需的时间tm 减小、晶核数密度和生长速度增大 ,从而明显改变Cu沉积层的质量 .当Cl-浓度在 10～ 2 0mg·L-1范围内 ,成核的晶核数密度达较大 ,即氯离子的最适宜添加量 .The initial stage of copper electrodeposition and the influence of chloride ions on the nucleation and growth of copper on glass carbon from acid sulphate solution were studied by using the cyclic voltammetry and the chronoamperometry method. Instantaneous nucleation with three dimensional growth is found for the solutions either with or without chloride. Obviously, chloride ions increase the nucleation rate and the nuclear number density of nuclei at the surface. Since the deposits are smooth, bright at high nuclear number densities, it can be concluded that chloride ions effectively promote the smooth and brightness of surface. The higher nuclear number densities are obtained at 10～20 mg·L -1 of chloride ions. Maintaining the optimum level chloride ion concentration is beneficial to electrodeposits.国家自然科学基金 (No .2 0 0 73 0 3 7);; 优秀国家重点实验室基金 (No .2 0 0 2 3 0 0 1)资助项

Effect of chloride ion on electrocrystallization of copper on glass carbon electrode

The initial stage of copper electrodeposition and the influence of chloride ions on the nucleation and growth of copper on glass carbon from acid sulphate solution were studied by using the cyclic voltammetry and the chronoamperometry method. Instantaneous nucleation with three-dimensional growth is found for the solutions either with or without chloride. Obviously, chloride ions increase the nucleation rate and the nuclear number density of nuclei at the surface. Since the deposits are smooth, bright at high nuclear number densities, it can be concluded that chloride ions effectively promote the smooth and brightness of surface. The higher nuclear number densities are obtained at 10 similar to 20 mg . L-1 of chloride ions. Maintaining the optimum level chloride ion concentration is beneficial to electrodeposits

Stuies on the Electrocurystallization of Copper,Cobalt,Co-Cu

本论文围绕多层膜Co/Cu的电化学制备进行了一些相关的基础研究。制备了高择优取向的Cu镀层做为制备多层膜的基底：研究了Cu和Co电结晶的初期行为，初步探讨了电化学因素对多层膜结构的影响。应用电化学测试技术，配合扫描电镜，研究了电流密度、搅拌方式及添加剂对Cu镀层择优取向、微结构及表面形貌的影响。采用恒电流方法在H2SO4-CuSO4电解液中，低电流密度下能够得到(220)取向的高择优镀层；高电流密度下，得到（111）取向的高择优镀层，高择优取向的电沉积层表面颗粒呈均匀排列，在(220）择优时为网状，(111)择优时为非常明显的六棱锥，电流密度是造成Cu镀层织构和表面形貌变化的主要原因，提出了电...The initial srtage of the electrodeposition of Cu and Co and the structure of Co/Cumultliayer electrodeposited on the Cu electrodeposits with highly prefeTTed orientationwere investigated by cyclic voltammetry，chronoamperometry，XRD and SEM XRD results indicated that Cu elctrodeposits from H2SO4－CuSO4 electrolyticsolution at current density 1.0－6.D Adm-2 and 15.0 Adm-2 had （220) and（111）preferr...学位：博士后院系专业：化学化工学院化学系_马克思主义哲学学号：BHBG0000

The Formation of Copper Electrodeposits with Highly Preferred Orientation and Their Surface Morphology

采用电化学方法在H2SO4-CuSO4电解液中获得高择优取向的Cu电沉积层.XRD结果表明,在1.0～6.0和15.0A·dm-2的电流密度下可分别获得(220)和(111)晶面高择优取向的Cu镀层.在同一电流密度下获得的Cu电沉积层织构度随镀层厚度增大而提高.SEM结果表明,在4.0和15.0A·dm-2的电流密度下可分别获得(220)和(111)织构Cu沉积层,其表面形貌在(220)晶面取向时呈现为细长晶粒连结成的网状,在(111)取向时则呈六棱锥状.提出了可能的机理,认为电流密度变化引起的Cu镀层择优取向晶面的转化归因于电结晶晶面生长方向及生长速度竞争的结果.Cu electrodeposits with highly preferred orientations were o btained fr om H 2 SO 4-CuSO 4 electrolytic solution.XRD results indicated that at current densities 1.0～6.0A·dm-2 and 15.0A·dm-2 ,the obtained Cu electrodeposits were respect ively shown in(220)and(111)highly preferred orientations.The value of texture co-efficient of Cu electrodeposited at a stationary current density was increased with its thicknes s.SEM resul ts re-vealed that the surface morphology o f the electrodeposits w ith(220)texture obtained at 4.0A·dm-2 appeared in network combined with needle crysta ls,and texture with(111 )at 15.0A ·dm-2 in hexagonal pyramid.The changes of the preferre d orientatio n effected by current density were ma inly attributed to the competitions between the grains g rowing direction and the rate during Cu electrocrystallization.国家自然科学基金(20073037);; 优秀国家重点实验室基金(20023001

Effects of Current Density and Bath Agitation on the Surface Morphology and Texture of Cu Electrodeposits

研究了 H2 SO4 +Cu SO4 电解液分别在静止、机械搅拌和空气搅拌作用下 ,电流密度对所获得的铜电沉积层晶体取向和表面形貌的影响 .XRD和 SEM实验结果都表明 ,电流密度是造成 Cu镀层织构和表面形貌变化的主要原因 .电流密度低于 6.0 A/dm2 时 ,Cu镀层呈现 (1 1 0 )晶面择优 ;高于 1 5 .0 A/dm2 时 ,呈现(1 1 1 )晶面择优 .随电流密度提高 ,Cu电结晶由侧向生长模式转向向上生长模式 .搅拌作用的加强有利于晶体的生长 .The texture and surface morphology of Cu electrodeposited on stainless steel at different current densities from H 2SO 4+CuSO 4 electrolyte solution under unstirring, mechanical agitation and air agitation condition have been studied by means of XRD and SEM technique. The results showed that the surface morphology and crystal orientation of Cu electrodeposits varied mainly with the current density used in deposition: at c.d. 15 0 A/dm 2, (111) orientation was preferred, and no obvious crystal orientation was observed at medium current density. Increase in current densities made the Cu electro crystallization varied from lateral to outward growth modes.国家自然科学基金 (2 0 0 73 0 3 7);; 优秀国家重点实验室基金 (2 0 0 2 3 0 0 1)资助项

Electrocrystallisation of cobalt during preparation of Co/Cu multilayers

The electrocrystallisation of cobalt onto a glassy carbon electrode from cobalt sulphate electrolytes either with or without the addition of a small amount of copper ions was investigated through the electrochemical techniques of cyclic voltammetry and chronoamperometry. Voltammetric results showed that the cobalt deposits obtained were impure and the overpotential for cobalt nucleation was low for electrolyte with a small amount of copper ions. Analysis of the current - time transients by chronoamperometry indicated that the nucleation mechanism of cobalt in cobalt sulphate solution occurred by a combination of two different kinds of parallel nucleation processes, instantaneous or progressive nucleation with two-dimensional or three-dimensional growth, which depended on the overpotential applied. However, in the presence of copper ions, the nucleation mechanism was in accordance with 3D growth under diffusion control. Progressive nucleation occurred at a lower overpotential and instantaneous nucleation at a higher overpotential. The deviation of the experimental data from the theoretical model was explained

Effects of Nicotinic Acid on Copper Electrodeposition in Acid Sulphate

对溶液A:0.8mol·L-1硫酸铜,0.6mol·L-1硫酸,5.0×10-5mol·L-1氯离子,1.0×10-4mol·L-1聚乙二醇的溶液,溶液B:在溶液A中加入2.0×10-2mol·L-1烟酸,pH为0.5,运用循环伏安和计时安培法研究玻碳电极上铜的电沉积行为.结果表明,铜的电沉积过程经历了晶核形成过程,其电结晶按瞬时成核和三维生长方式进行.烟酸的加入对铜的电沉积具有阻化作用,但不改变铜的电结晶机理.沉积层的X射线衍射表明Cu为面心立方结构,在烟酸存在下沉积层出现(220)高择优取向,这可能是烟酸在Cu(220)晶面上发生强烈吸附作用的结果.Initial stages of electrodeposition of copper on glassy carbon electrode from 0.8 mol·L-1 copper sulphate electrolyte solution containing 2.0×10-2 mol·L-1 nicotinic acid are studied using cyclic voltammetry and chronoamperometry.The results show that nicotinic acid (NA) produces an inhibition of copper deposition,probably related to the adsorption of nicotinic acid.The initial deposition kinetics corresponds to a model including instantaneous nucleation and diffusion controlled growth.The X ray diffraction results indicate that copper deposits exhibit face centered cubic structure and (220) highly preferred orientation.Nicotinic acid produces uniform and smooth surfaces of copper deposit.国家自然科学基金(20073037)和厦门大学科学研究基金资助项