Dual Effects of CTAB on Co-deposition of SiC/Cu in Micro Via

Micro via interconnector is the most important part in three dimension (3D) packaging of integrated circuit (IC) devices. The reliability of the micro via interconnector is the core issue of 3D packaging. It is an innovative idea to fill the micro via with nanocomposite by co-deposition process and hence improve the thermal property of the interconnector. However, co-deposition of metal and nanoparticles in micro via needs to overcome two difficulties: 1) Non-defect filling of micro via; 2) Increasing content of nanoparticles incorporating into the metal layer. It is crucial to find additives which have both inhibition effect on electrodeposition to achieve non-defect filling in micro via, and surface modification effect on nanoparticles to increase the content of nanoparticles in nanocomposite. This study investigated the dual effects of Cetyltrimethyl Ammonium Bromide (CTAB) as suppressor and surfactant on co-deposition of SiC/Cu in micro via. Experimental results showed that the CTAB had inhibition effect on electrodeposition, and non-defect filling of micro via was achieved by adding CTAB into the electrodeposition bath; The content of SiC nanoparticles in the nanocomposite was enhanced by adding CTAB into the co-deposition bath. Volume percentage (vol.%) of SiC in nanocomposite of the micro via was increased from 6.4 vol.% to 12.91 vol.% as the concentration of CTAB increased from 0 g/L to 0.3 g/L.