PDF(2858 KB)
PDF(2858 KB)
PDF(2858 KB)
硅晶圆上窄节距互连铜凸点
Copper bumping for fine pitch interconnections
为了满足日益减小的互连节距需求,该文研究了晶圆上窄节距铜凸点的成型技术。铜凸点成型主要包括溅射凸点下金属化层(under bump metallization, UBM)、 厚胶光刻、电镀、去胶、刻蚀UBM等。通过研究甩胶、前烘、曝光、显影、后烘等技术参数,优化了正性光刻胶AZ4620的厚胶光刻工艺,并通过理论分析验证了其合理性。同时,进行了湿法腐蚀和干法刻蚀UBM的对比实验,得到了用于超窄节距凸点去除UBM的不同方法。最终获得了节距20 μm、 直径10 μm、 高度10 μm的凸点,侧壁垂直度达到83.95°; 并采用剪切力测试方法表征晶圆上铜凸点强度的分布特点,得到剪切强度接近体材料的剪切强度。
Fine pitch copper bumping on wafers was characterized to meet the demand for smaller interconnections. Electroplating copper bumping involves under bump metallization (UBM) sputtering, thick photoresist, copper electroplating, photoresist removal and UBM etching. The spin coating, soft baking, exposure, developing and post exposure baking of AZ4620 thick photoresist were optimized theoretically. Wet and dry UBM etching are also compared. Copper bumps were fabricated with a 20 μm pitch, 10 μm diameter and 10 μm height with a 83.95° sidewall. The wafer level copper strength uniformity was also checked by shear testing.
thick photoresist / copper bumping / fine pitch interconnection
| [1] | LIU He, Salomonsen G, WANG Kaiying, et al.Wafer-level Cu/Sn to Cu/Sn SLID-bonded interconnects with increased strength [J]. IEEE Trans Compon Packaging Manuf Technol, 2011, 1(9): 1350-1358. |
| [2] | Fan A, Rahman A, Reif R. Copper Wafer Bonding [J]. Electrochem Solid-State Lett. 1999, 2(10): 534-536. |
| [3] | ITRS. International Technology Roadmap for Semiconductors: Interconnect [Z/OL]. [2012-10-11]. http://www.itrs.net/Links/2011itrs/2011Chapters/2011Interconnect.pdf. |
| [4] | ITRS. International Technology Roadmap for Semiconductors: assembly and packaging [Z/OL] [2012-10-11]. http://www.itrs.net/Links/2011itrs/2011Chapters/2011AP.pdf. |
| [5] | CHENG Yao, LIN Chingyao, Wei D H, et al.Wall profile of thick photoresist generated via contact printing [J]. J Microelectromech S, 1999, 8(1): 18-22. |
| [6] | 王水弟, 蔡坚, 谭智敏, 等. 用于圆片级封装的金凸点研制 [J]. 半导体技术, 2004, 29(4): 28. WANG Shuidi, CAI Jian, TAN Zhimin, et al. Research of gold bump for wafer level package [J]. Semiconductor Technology, 2004, 29(4): 28 (in Chinese). |
| [7] | Yoon J B, Han C H, Yoon E, et al.Monolithic fabrication of electroplated solenoid inductors using three- dimensional photolithography of a thick photoresist [J]. Jpn J Appl Phys, 1998, 37(12): 7081-7085. |
| [8] | Mark G, Craig B, Shawn O'C. Next generation fine pitch Cu pillar technology-enabling next generation silicon nodes [C]// 61st IEEE ECTC Conf, Florida USA: IEEE Press, 2011: 612-618. |
| [9] | 罗铂靓, 杜惊雷, 唐雄贵, 等. 用于微器件加工的AZ4620厚胶光刻工艺研究 [J]. 半导体技术, 2005, 30(7): 2-4. LUO Boliang, DU Jinglei, TANG Xionggui, et al. Technical study of AZ4620 thick photoresist for micro fabrication [J]. Semiconductor Technology, 2005, 30(7): 2-4 (in Chinese). |
| [10] | 中国科学院化学研究所. 光致抗蚀剂 [M]. 北京: 科学出版社, 1977. Institute of Chemistry. Chinese Academy of Sciences. Photoresist [M]. Beijing: Science Press, 1977 (in Chinese). |
| [11] | 杨瑨. 用于倒装芯片互连的窄节距印刷凸点技术研究 [D]. 北京: 清华大学, 2010: 37-38. YANG Jin. Fine Pitch Stencil Printing Bumps for Flip Chip Interconnect Applications [D]. Beijing: Tsinghua University, 2010: 37-38 (in Chinese). |
| [12] | Melo F, Joanny J F, Fauve S. Fingering instability of spinning drops [J]. Phys Rev Lett, 1989, 63(8): 1958-1959. |
/
| 〈 |
|
〉 |
