Survey of the metal nucleation processes on silicon surfaces in fluoride solutions:: from dilute HF to concentrated NH4F solutions
Survey of the metal nucleation processes on silicon surfaces in fluoride solutions:: from dilute HF to concentrated NH4F solutions
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DOI：
10.1016/s0022-0728(02)01280-9
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发表时间：
2003-11-15
影响因子：
4.5
通讯作者：
Osaka, T
中科院分区：
文献类型：
--
作者：
Chemla, M;Homma, T;Osaka, T
众所周知，痕量金属杂质对硅表面的污染是ULSI电路生产中的有害影响的原因。对影响氟化物溶液在硅衬底上自发成核的因素进行了广泛的实验研究。在酸性介质（稀HF溶液）中，只能沉积贵金属。选择Cu元素成核的机制作为模型实例。第一阶段是纳米尺度的Cu晶体的外观，通过AFM显微镜观察。由于形成短路的电化学电池，这些核很快引起腐蚀坑。在浓NH4F溶液中，Si样品的开路电位（ocp）是高度负的，并且为成核提供了有效的驱动力，即使对于常见的金属如Fe也是如此。我们的研究结果表明，Fe的沉积是很难观察到的，当只存在Fe，但在Cu的存在下，观察到的催化作用，导致共沉积的Fe + Cu核。在所有情况下，Si衬底上的表面缺陷都是由腐蚀坑产生的。(C)2002 Elsevier Science B.V.保留所有权利。
As is well known, contamination of the silicon surface by trace metal impurities is responsible for detrimental effects in the production of ULSI circuits. An extensive experimental study of the factors influencing the spontaneous metal nucleation from fluoride solutions on Si substrates was undertaken. In acidic media (dilute HF solution) only noble metals can be deposited. The mechanism for the formation of Cu element nuclei was chosen as a model example. The first stage was the appearance of Cu crystals of a nanoscopic scale, observed by AFM microscopy. These nuclei soon induce corrosion pits due to the formation of a short-circuited electrochemical cell. In concentrated NH4F solutions, the open circuit potential (ocp) of Si samples is highly negative and provides an efficient driving force for nucleation even for common metals like Fe. Our results show that the deposition of Fe is hardly observable when Fe only is present, but in the presence of Cu, a catalytic effect is observed leading to the co-deposition of Fe + Cu nuclei. In all cases surface defects on the Si substrate are generated by the corrosion pits. (C) 2002 Elsevier Science B.V. All rights reserved.