Title:

2D Material Transfer for Advanced Semiconductor Integration: Opportunities for Temporary Bonding and Debonding Platform

Abstract:
Transition metal dichalcogenides (MX2), including WS2 and MoS2, are 2D material candidates for monolithic channel integration in sub-nanometer-node logic devices due to their ~0.7 nm single-layer thickness, dielectric constant >50% relative to silicon, and mobility that is largely independent of channel thickness — properties that support continued gate-length scaling under CFET and GAA architectures.

Because high-quality 2D materials require growth on thermally resistant substrates (e.g., sapphire), integrating them into device flows depends on reliably transferring the material to a target wafer, creating an opportunity for temporary bonding and debonding (TBDB) materials. This presentation reviews the background, merits of 2D materials and collaborative work between imec and Brewer Science in evaluating adhesive and light release materials for 300 mm WS2 transfer, alongside electrical validation showing transferred WS2 monolayers retain characteristics comparable to as-grown material. Key learnings include the sensitivity of transfer quality to bonding temperature relative to Tg, persistent monolayer adhesive residue challenges, method of debonding, and early proof-of-concept results for metal-assisted (Bi) transfer to mitigate residue and enable water-free debonding. Fundamental gaps remain in polymer structure-property relationships for 2D materials, solvent compatibility, low-temperature bonding without cracking, and bond/debond process optimization — representing the core research questions for future work.