Adhesion Investigation Between Metal and Benzocyclobutene (BCB) Polymer Dielectric Materials in 3-D Integration Applications

In this paper, the interfacial adhesion strength between metal layer and benzocyclobutene (BCB) polymer dielectric in 3-D integration applications is investigated. The effects of layer thickness, layer stacking order, and additional adhesion layer of titanium (Ti) layer between copper (Cu) and BCB polymer are investigated. Surprisingly, the conventional titanium adhesion layer commonly used in the semiconductor industry weakens the interfacial adhesion strength between copper and BCB. Additionally, to figure out the interfacial adhesion mechanisms, the interfacial structures probed by sum-frequency-generation vibrational spectroscopy are correlated to the adhesion strengths measured from corresponding sample interfaces. It is found that ordered C-H groups at the metal/BCB interface, such as titanium/BCB or molybdenum/BCB, lead to weak interfacial adhesion strength, whereas disordered interfaces, i.e., copper/BCB, lead to strong interfacial adhesion strength.

[1]  Y. Shen,et al.  Surface properties probed by second-harmonic and sum-frequency generation , 1989, Nature.

[2]  Jian-Qiang Lu,et al.  3-D Hyperintegration and Packaging Technologies for Micro-Nano Systems , 2009, Proceedings of the IEEE.

[3]  Cheng-Ta Ko,et al.  Wafer-level bonding/stacking technology for 3D integration , 2010, Microelectron. Reliab..

[4]  P. Cremer,et al.  Probing molecular structure at interfaces for comparison with bulk solution behavior: water/2-propanol mixtures monitored by vibrational sum frequency spectroscopy. , 2006, Journal of the American Chemical Society.

[5]  E. Ogawa,et al.  Interface reliability assessments for copper/low-k products , 2004, IEEE Transactions on Device and Materials Reliability.

[6]  Jung-Ju Lee,et al.  Evaluation of mechanical interlock effect on adhesion strength of polymer–metal interfaces using micro-patterned surface topography , 2010 .

[7]  S. Franssila.  Introduction to microfabrication , 2004 .

[8]  Zhan Chen,et al.  Molecular level understanding of adhesion mechanisms at the epoxy/polymer interfaces. , 2012, ACS applied materials & interfaces.

[9]  Robert S. Patti,et al.  Three-Dimensional Integrated Circuits and the Future of System-on-Chip Designs , 2006, Proceedings of the IEEE.

[10]  G. Somorjai,et al.  An SFG study of interfacial amino acids at the hydrophilic SiO2 and hydrophobic deuterated polystyrene surfaces. , 2011, Journal of the American Chemical Society.

[11]  Mitsumasa Koyanagi,et al.  Handbook of 3D Integration , 2008 .

[12]  Zhan Chen.  Understanding surfaces and buried interfaces of polymer materials at the molecular level using sum frequency generation vibrational spectroscopy , 2007 .

[13]  J.-Q. Lu,et al.  Wafer bonding of damascene-patterned metal/adhesive redistribution layers for via-first three-dimensional (3D) interconnect , 2005, Proceedings Electronic Components and Technology, 2005. ECTC '05..

[14]  Frank Niklaus,et al.  Wafer-Level Heterogeneous Integration for MOEMS, MEMS, and NEMS , 2011, IEEE Journal of Selected Topics in Quantum Electronics.

[15]  S. Baldelli,et al.  Surface structure at the ionic liquid-electrified metal interface. , 2008, Accounts of chemical research.

[16]  M. Oh-e,et al.  Sum-frequency generation (SFG) vibrational spectroscopy of side alkyl chain structures of polyimide surfaces , 2000 .

[17]  Kazunari Domen,et al.  Formulas for the Analysis of the Surface SFG Spectrum and Transformation Coefficients of Cartesian SFG Tensor Components , 1992 .

[18]  Garth J. Simpson,et al.  A Unified Treatment of Selection Rules and Symmetry Relations for Sum-Frequency and Second Harmonic Spectroscopies , 2004 .

[19]  T. Jiang,et al.  Adhesion improvement for polymer dielectric to electrolytic-plated copper , 2010, 2010 Proceedings 60th Electronic Components and Technology Conference (ECTC).

[20]  Robert C. Cammarata,et al.  SURFACE AND INTERFACE STRESS EFFECTS IN THIN FILMS , 1994 .

[21]  C. Fellous,et al.  Electromigration and adhesion improvements of thick Cu/BCB architecture in BiCMOS RF technology , 2006 .

[22]  Peter Ramm,et al.  Handbook of 3D integration : technology and applications of 3D integrated circuits , 2012 .

[23]  Zhan Chen,et al.  Investigating buried polymer interfaces using sum frequency generation vibrational spectroscopy. , 2010, Progress in polymer science.

[24]  P. Somasundaran,et al.  Introduction to surface chemistry and catalysis , 1997 .