in iwa B p C,

the niti e b tion for decreasing the total global interconnect length that can lim-it IC performance. It refers to multiple conv chips/wafers may be stacked vertically an nected [1]. Based on current research and has the potential to dramatically enhance c ty in i s (ME ey tech e perfo nding, ximize physical properties such as low dielectric constant, low moisture absorption, low cure temperature, high degree of planarization, low level of ionic contaminants, high optical clarity, good thermal stability, excellent chemical resistance, and good compatibility with various metallization systems [4,5]. The monomer structure of BCB is shown in Fig. 1 [6]. In this research, we investigated the process optimization and studied the bonding mechanism of BCB-to-oxide hybrid bonding for 3D IC applications. layer, 2 lm PECVD oxide layer, and 3 lm BCB polymer layer, were followed by another 30 min DI water rinse and spin dried. After surface preparation, PECVD oxide and thermal oxide samples were bonded directly to BCB samples (face-to-face), respectively, at 200 C, 250 C, 300 C, 350 C, and 400 C for 30 min and 50 min. The bonding ambient was N2 or atmosphere. All the bonding experiments were under a 50 N bonding force. After bonding, the bonding quality and bond strength between BCB and PECVD/thermal oxide were examined using razor test and pulling test, respectively. The two surfaces of bonded samples after razor/pulling test and bonded interfaces were analyzed by optical microscope and scanning electron microscope. ⇑ Corresponding author