Imec unlocks system-level III-V chiplet integration on Si-CMOS
By combining high-density embedded capacitors, a scalable modeling framework for passive components, and laser-assisted bonding for III-V chiplet assembly, the platform lays the foundation for next-generation wireless (mmWave and sub-THz) systems.
Imec, a Belgium-based research and innovation center in nanoelectronics and digital technologies, is evolving its 300mm RF silicon interposer into a system-level platform for the heterogeneous integration of III-V chiplets on Si-CMOS.
By uniquely combining high-density embedded capacitors, a scalable modeling framework for passive components, and laser-assisted bonding for III-V chiplet assembly, the platform lays the foundation for next-generation wireless (mmWave and sub-THz) systems and RF-grade signal handling for ultrafast data center applications, Imec said in a press release.
“A key lever to reduce III-V chiplet size and cost is the offloading of passive components —such as decoupling capacitors — onto the RF silicon interposer,” said Xiao Sun, principal member of technical staff at Imec. “In a paper presented at this year’s IMS/RFIC conference, we demonstrate how combining this offloading approach with a new MIMCAP architecture enables a 10-to-100-fold increase in capacitance density compared to typical on-chip capacitors in III-V technologies.”
Imec’s new MIM capacitor (MIMCAP) architecture combines a high-k aluminum-hafnium-oxide dielectric with three-dimensional (3D) oxide-stud structures in the back-end-of-line (BEOL).
Complementing this effort, imec recently presented a modeling framework for RF interposer passives, validated up to the sub-THz regime (~300GHz).
Imec also demonstrated the use of laser-assisted bonding to integrate III-V chiplets onto its RF silicon interposer, enabling assembly of chiplets on a complex, passives-rich stack without compromising thermal budgets, or damaging temperature-sensitive interposer layers.
Imec’s approach achieves alignment accuracy below 600nm, and rotational misalignment below 0.05° across 43 devices. RF measurements confirm preserved performance after assembly, with reflection below −15 dB in the 110-170GHz range, demonstrating a viable path toward fully assembled high-frequency chiplet-based systems, the press release said.