TY - GEN
T1 - Comprehensive Interface Adhesion Characterization for Advanced Semiconductor Packaging
AU - Kim, Dong Jun
AU - Lee, Sun Woo
AU - Choi, Won
AU - Chang, Ho Jun
AU - Lee, Inhwa
AU - Park, Seungju
AU - Lee, Jihyun
AU - Kim, Joong Jung
AU - Kang, Sumin
AU - Kim, Taek Soo
N1 - Publisher Copyright:
©2025 IEEE.
PY - 2025
Y1 - 2025
N2 - As the layer number of semiconductor devices continue to increase and structures become complex, the mechanical reliability of back-end-of-line (BEOL) interconnect structures becomes increasingly critical for device performance and manufacturing yield. This study presents a comprehensive investigation of interfacial adhesion energies in BEOL structures using the integrated measurement method, double cantilever beam (DCB) fracture mechanics testing to identify the weakest interface and optimize material selection and process parameters. We systematically characterized three critical interfaces: Cu–Cap (Capping layer), Cu–IMD (inter-metal dielectric), and IMD–Cap using unified measurement methods. For Cu–Cap interfaces, two different capping materials (Cap1 and Cap2) were evaluated under various surface treatment conditions. NH3 plasma treatment and H2 - NH3 plasma treatments were applied, with treatment effects analyzed through chemical bonding characterization. Results showed that the enhanced surface treatment increased Cu–Si bonding ratios at the Cu–Cap1 interface through the removal of copper oxide layers, thereby improving interfacial adhesion energy. For Cu–IMD interfaces, we compared two IMD materials with different dielectric constants (κ values). IMD1 with lower κ exhibited significantly lower adhesion energy (0.72 ± 0.03, normalized) compared to IMD2 with higher κ (1.47 ± 0.30), attributed to increased porosity and defect densities in low-κ materials that introduce nonuniform bonding characteristics and stress concentration points. The IMD–Cap interface demonstrated remarkable sensitivity to deposition sequence. Surface energy analysis revealed that the higher surface energy of Cap2 (49.01 mJ/m2) compared to IMD1 (32.54 mJ/m2) enhanced physical adsorption of CVD precursors, explaining the deposition sequence dependency. These findings provide critical insights for enhancing BEOL reliability through optimized material selection, surface treatment protocols, and control of deposition sequence. The quantitative adhesion energy database and mechanical analysis will contribute to the development of more robust and reliable interconnect structures for advanced semiconductor packaging applications.
AB - As the layer number of semiconductor devices continue to increase and structures become complex, the mechanical reliability of back-end-of-line (BEOL) interconnect structures becomes increasingly critical for device performance and manufacturing yield. This study presents a comprehensive investigation of interfacial adhesion energies in BEOL structures using the integrated measurement method, double cantilever beam (DCB) fracture mechanics testing to identify the weakest interface and optimize material selection and process parameters. We systematically characterized three critical interfaces: Cu–Cap (Capping layer), Cu–IMD (inter-metal dielectric), and IMD–Cap using unified measurement methods. For Cu–Cap interfaces, two different capping materials (Cap1 and Cap2) were evaluated under various surface treatment conditions. NH3 plasma treatment and H2 - NH3 plasma treatments were applied, with treatment effects analyzed through chemical bonding characterization. Results showed that the enhanced surface treatment increased Cu–Si bonding ratios at the Cu–Cap1 interface through the removal of copper oxide layers, thereby improving interfacial adhesion energy. For Cu–IMD interfaces, we compared two IMD materials with different dielectric constants (κ values). IMD1 with lower κ exhibited significantly lower adhesion energy (0.72 ± 0.03, normalized) compared to IMD2 with higher κ (1.47 ± 0.30), attributed to increased porosity and defect densities in low-κ materials that introduce nonuniform bonding characteristics and stress concentration points. The IMD–Cap interface demonstrated remarkable sensitivity to deposition sequence. Surface energy analysis revealed that the higher surface energy of Cap2 (49.01 mJ/m2) compared to IMD1 (32.54 mJ/m2) enhanced physical adsorption of CVD precursors, explaining the deposition sequence dependency. These findings provide critical insights for enhancing BEOL reliability through optimized material selection, surface treatment protocols, and control of deposition sequence. The quantitative adhesion energy database and mechanical analysis will contribute to the development of more robust and reliable interconnect structures for advanced semiconductor packaging applications.
KW - BEOL
KW - deposition sequence
KW - interfacial adhesion
KW - semiconductor packaging
KW - surface treatment
UR - https://www.scopus.com/pages/publications/105031608912
U2 - 10.1109/IMPACT67645.2025.11281687
DO - 10.1109/IMPACT67645.2025.11281687
M3 - Conference contribution
AN - SCOPUS:105031608912
T3 - Proceedings of Technical Papers - International Microsystems, Packaging, Assembly, and Circuits Technology Conference, IMPACT
SP - 94
EP - 97
BT - Proceedings - 20th International Microsystems, Packaging, Assembly and Circuits Technology Conference
PB - IEEE Computer Society
T2 - 20th International Microsystems, Packaging, Assembly and Circuits Technology Conference, IMPACT 2025
Y2 - 21 October 2025 through 24 October 2025
ER -