TY - JOUR
T1 - Investigative characterization of delamination at TiW-Cu interface in low-temperature bonded interconnects
AU - Golim, Obert
AU - Vuorinen, Vesa
AU - Ross, Glenn
AU - Suihkonen, Sami
AU - Paulasto-Kröckel, Mervi
N1 - Publisher Copyright:
© 2024 The Authors
PY - 2024/3
Y1 - 2024/3
N2 - The trend for heterogeneous integration has driven the need for a low-temperature bonding process. Cu-Sn-In based solid-liquid interdiffusion (SLID) bonding technology has been presented as a viable option. However, previous studies have also reported that issues might exist in the interconnect interface towards the substrate, leading to the formation of intermetallic layers at undesired locations. This study carried out a series of characterization methods to determine the root cause of this issue. Cross-sectional observations showed that the problem occurs particularly at the TiW-Cu interface. Examination of the adhesion layer showed possible impurities existing in the layers, compromising its adhesion to copper. Residual stress analyses displayed opposing loading conditions at the interface. The interplay of the two factors resulted in the delamination of the TiW-Cu interface, leading to a pathway for Sn–In atoms. Furthermore, several methods are proposed to mitigate this issue.
AB - The trend for heterogeneous integration has driven the need for a low-temperature bonding process. Cu-Sn-In based solid-liquid interdiffusion (SLID) bonding technology has been presented as a viable option. However, previous studies have also reported that issues might exist in the interconnect interface towards the substrate, leading to the formation of intermetallic layers at undesired locations. This study carried out a series of characterization methods to determine the root cause of this issue. Cross-sectional observations showed that the problem occurs particularly at the TiW-Cu interface. Examination of the adhesion layer showed possible impurities existing in the layers, compromising its adhesion to copper. Residual stress analyses displayed opposing loading conditions at the interface. The interplay of the two factors resulted in the delamination of the TiW-Cu interface, leading to a pathway for Sn–In atoms. Furthermore, several methods are proposed to mitigate this issue.
KW - Delamination
KW - Interconnect
KW - Interface
KW - SLID
UR - http://www.scopus.com/inward/record.url?scp=85185839155&partnerID=8YFLogxK
U2 - 10.1016/j.matchar.2024.113772
DO - 10.1016/j.matchar.2024.113772
M3 - Article
SN - 1044-5803
VL - 209
JO - Materials Characterization
JF - Materials Characterization
M1 - 113772
ER -