TY - GEN
T1 - Utilizing Co as a contact metallization for wafer-level Cu-Sn-In SLID bonding used in MEMS and MOEMS packaging
AU - Emadi, Fahimeh
AU - Vuorinen, Vesa
AU - Paulasto-Kröckel, Mervi
N1 - Funding Information:
This work has been funded by iRel40. iRel40 is a European co-funded innovation project that has been granted by the ECSEL Joint Undertaking (JU) under grant agreement No 876659. The funding of the project comes from the Horizon 2020 research programme and participating countries. National funding is provided by Germany, Austria, Belgium, Finland (Innovation Funding Agency, Business Finland), France, Italy, the Netherlands, Slovakia, Spain, Sweden, and Turkey
Publisher Copyright:
© 2022 IEEE.
| openaire: EC/H2020/876659/EU//iRel40
PY - 2022
Y1 - 2022
N2 - Many MEMS and MOEMS devices require hermetic packaging with preferably no postprocessing after the MEMS device's releasing. Wafer-level Solid-Liquid Interdiffusion (SLID) bonding can provide simultaneous hermetic packaging and better electrical interconnects. Moreover, employing a physically deposited contact metallization on the device wafer instead of chemically deposited layers (such as electrochemical Cu) is of utmost importance as far as reducing the complexity of the MEMS/MOEMS packaging process integration is concerned. The current work studied the possibility of utilizing Co as a contact metallization layer for the low-temperature Cu-Sn-In-based SLID bonding. In order to guarantee the long-term reliability of the devices, a fundamental understanding of the formation and evolution of interconnection microstructures and mechanical characterization of the joint is of utmost importance. In this work, Cu-Sn-In electroplated Si chips were bonded to Co substrates at a temperature range 160-250°C. During the bonding process, a single intermetallic compound (IMC) (Cu,Co)6(Sn,In)5 formed at the bonding area, with no detectable Cu3Sn phase that causes voids formation. The Young's modulus and hardness of (Cu,Co)6(Sn,In)5 and Cu6Sn5, as a reference, were measured as 124.8±0.5 and 6.2±0.5, 114±1 and 6.7±0.5 MPa, respectively. Furthermore, the current study was able to produce a fully IMC joint of Cu-Sn-In/Co SLID system at 220°C for bonding time as short as 20 minutes.
AB - Many MEMS and MOEMS devices require hermetic packaging with preferably no postprocessing after the MEMS device's releasing. Wafer-level Solid-Liquid Interdiffusion (SLID) bonding can provide simultaneous hermetic packaging and better electrical interconnects. Moreover, employing a physically deposited contact metallization on the device wafer instead of chemically deposited layers (such as electrochemical Cu) is of utmost importance as far as reducing the complexity of the MEMS/MOEMS packaging process integration is concerned. The current work studied the possibility of utilizing Co as a contact metallization layer for the low-temperature Cu-Sn-In-based SLID bonding. In order to guarantee the long-term reliability of the devices, a fundamental understanding of the formation and evolution of interconnection microstructures and mechanical characterization of the joint is of utmost importance. In this work, Cu-Sn-In electroplated Si chips were bonded to Co substrates at a temperature range 160-250°C. During the bonding process, a single intermetallic compound (IMC) (Cu,Co)6(Sn,In)5 formed at the bonding area, with no detectable Cu3Sn phase that causes voids formation. The Young's modulus and hardness of (Cu,Co)6(Sn,In)5 and Cu6Sn5, as a reference, were measured as 124.8±0.5 and 6.2±0.5, 114±1 and 6.7±0.5 MPa, respectively. Furthermore, the current study was able to produce a fully IMC joint of Cu-Sn-In/Co SLID system at 220°C for bonding time as short as 20 minutes.
KW - Co contact metallization
KW - Cu-Sn SLID bonding
KW - Cu-Sn-In SLID bonding
KW - Reliability
KW - TLP bonding
UR - http://www.scopus.com/inward/record.url?scp=85143138410&partnerID=8YFLogxK
U2 - 10.1109/ESTC55720.2022.9939539
DO - 10.1109/ESTC55720.2022.9939539
M3 - Conference article in proceedings
AN - SCOPUS:85143138410
T3 - 2022 IEEE 9th Electronics System-Integration Technology Conference, ESTC 2022 - Proceedings
SP - 359
EP - 363
BT - 2022 IEEE 9th Electronics System-Integration Technology Conference, ESTC 2022 - Proceedings
PB - IEEE
T2 - Electronics System-Integration Technology Conference
Y2 - 13 September 2022 through 16 September 2022
ER -