화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.163, No.8, D434-D441, 2016
The Influences of Iodide Ion on Cu Electrodeposition and TSV Filling
Through silicon via (TSV) technology has been researched for 3-dimensional packaging of electronic devices, and Cu electrodeposition has been used for TSV filling. The organic additives are one of the most important factors in Cu electrodeposition affecting Cu gap-filling, and the leveler usually plays a decisive role. In this research, iodide ion (I-) is adopted instead of organic leveler for Cu bottom-up filling. The behaviors of I- are investigated by various types of electrochemical analyses. Especially, the influences of I- on the adsorption of the accelerator and suppressor are extensively studied, and it is confirmed that I- makes the suppression layer robust while reducing the adsorption of the accelerator. Also, it was observed that the effect of I- is greater under the strong convection of electrolytes than without convection, meaning that I- could induce selective deposition at the bottom of the features. Based on this, TSV-scaled trenches are successfully filled by potentiostatic Cu electrodeposition in the presence of the accelerator, suppressor, and I- without any organic levelers. (C) 2016 The Electrochemical Society. All rights reserved.