胺结构调控硅通孔电镀铜单组分添加剂的性能

Regulation of Ethylenediamine Structure on the Properties of Single Component Additive for Copper Electroplating in Through Silicon Vias

通过季铵化反应对硅通孔(TSV)铜互连单组分电镀添加剂Tetronic 701(TE701)中乙二胺结构进行了电荷与空间位阻调控,获得两种甲基化季铵盐和两种磺酸丙基化季铵盐衍生物。采用恒电流测试和循环伏安法分析了衍生物的电化学性能,通过TSV芯片电镀铜研究了不同衍生物的电镀性能。结果表明,季铵盐衍生化虽未改变TE701作为添加剂的作用机制,但乙二胺结构上正电荷增加会导致TE701衍生物在阴极表面的吸附增强,从而减少脱附位点,并减缓TSV上部侧壁的铜沉积;而乙二胺连接带负电的磺酸丙基则会显著降低TE701衍生物的吸附强度,使其失去超填充性能。

Different quaternizations were performed on the ethylenediamine structure of Tetronic 701(TE701),a single component additive for copper interconnect electroplating in through silicon vias(TSVs),to regulate its charge and steric hindrance.Two kinds of methylated quaternary ammonium derivatives and two kinds of sulfopropyl quaternary ammonium derivatives were synthesized.The electrochemical properties of the obtained derivatives were analyzed by galvanostatic potential transient measurements and cyclic voltammetry.The electroplating performances of different derivatives were studied by electroplating copper on the TSV chips.The results show that quaternary ammonium derivatization does not change the action mechanism of TE701 as an additive.However, the increase of positive charges on the ethylenediamine structure will lead to stronger adsorption of TE701 derivatives on the surface of cathode, which will reduce the desorption sites and slow down the deposition of copper on the upper sidewall of TSVs.And the negatively charged sulfopropyl group attached to the ethylenediamine structure will significantly decrease the adsorption strength of the TE701 derivatives, resulting in the loss of superfilling characteristics.