High‐Fidelity and Large‐Area Transfer of Metal Thin Films for Precision Nanofabrication and Integration

Metal electrodes are indispensable in modern electronic and optoelectronic devices, but conventional deposition methods often introduce interface defects, Fermi-level pinning, and thermal or chemical incompatibilities-especially when integrating with 2D semiconductors or unconventional substrates. Transfer printing offers a promising alternative by forming clean, damage-free interfaces and supporting diverse substrate types. However, existing methods face limitations depending on the material system used: sacrificial layers (e.g., polymethyl methacrylate, PMMA; polyvinyl alcohol, PVA) can introduce contamination risks, while soft stamps like polydimethylsiloxane (PDMS) suffer from poor registration accuracy and limited scalability. In this paper, a fully dry, wafer-scale metal thin film transfer method enabled by a shape memory polymer (SMP) with sharply tunable adhesion is presented. By utilizing its sharp thermomechanical transition, the SMP allows precise control of interfacial adhesion, enabling clean and reliable pick-up and release of metal films. High-fidelity transfer of various metals (Cu, Ag, Au, Al) onto flexible and rigid substrates with alignment error as low as ≈0.2 µm over 27 mm (≈0.001%) is demonstrated. Further, a systematic study of adhesion behavior and interfacial mechanics is conducted, providing insights to guide process optimization. This record-level registration, along with dry processing and broad material compatibility, establishes a scalable, contamination-free platform for advanced device integration and heterogeneous systems.