Effects of process conditions on properties of electroplated Ni thin films for microsystem applications
Effects of process conditions on properties of electroplated Ni thin films for microsystem applications
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DOI：
10.1149/1.2223302
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发表时间：
2006-01-01
影响因子：
3.9
通讯作者：
Milne, W. I.
中科院分区：
文献类型：
--
作者：
Luo, J. K.;Pritschow, M.;Milne, W. I.
系统地研究了电镀温度和电流密度对镍薄膜性能的影响。的电阻率和温度系数保持不变，在不同的工艺条件下，虽然这些属性的值分别约为散装镍材料的三倍和一半。最佳条件J = 2 mA/cm（2）和60 ℃被发现的无应力镍薄膜。当在高温和低电流密度下电镀时，Ni膜的弹性模量与块体Ni的弹性模量一样高（210 GPa），然后随着电镀电流密度的增加而线性降低，当电镀电流密度为30 mA/cm（2）时，降低到85 GPa。据信，较高的镀覆速率产生低密度的细晶粒结构，导致高拉伸应力和低弹性模量，而较低的镀覆速率产生具有接近本体Ni的弹性模量和压缩残余应力的致密材料。材料的弹性模量与应力之间存在明显的相关性，这表明材料在高的拉应力下可能会出现低的弹性模量，不适合于微机电系统器件的制造。(c)2006年电化学学会。
The properties of electroplated Ni thin films have been systematically investigated as a function of plating temperature and current density. The resistivity and its temperature coefficient remain unchanged on varying the process conditions, though the values of these properties are approximately three times and one-half of those of bulk Ni material, respectively. Optimal conditions of J = 2 mA/cm(2) and 60 degrees C were found for stress-free Ni thin films. The modulus of elasticity of the Ni films is as high as that of bulk Ni (210 GPa) when plated at high temperature and low current density, and then decreases linearly with increasing plating current density, down to 85 GPa at a plating current density of 30 mA/cm(2). It is believed that higher plating rates produced fine-grained structures of low density, leading to a high tensile stress and low modulus of elasticity, while lower plating rates produced a dense material with a modulus of elasticity close to that of bulk Ni and a compressive residual stress. A clear correlation between modulus of elasticity and the stress exists, which reveals that a material under high tensile stress may posses a low modulus of elasticity, and is not suitable for fabrication of microelectromechanical systems devices. (c) 2006 The Electrochemical Society.