Low-Temperature Plasma-Assisted Metallization of PTFE: A Focused Review

Polytetrafluoroethylene (PTFE) is an important dielectric and structural substrate for high-frequency, flexible, low-background, and other electronic systems because of its low dielectric loss, high electrical resistivity, low moisture absorption, chemical inertness, and thermal stability. However, its fluorine-rich surface, low surface energy, and weak boundary layer hinder metal nucleation and interfacial bonding, frequently leading to discontinuous film growth, high interfacial resistance, and premature delamination. This focused review summarizes recent progress in low-temperature plasma-assisted metallization of PTFE, with particular emphasis on the relationships among plasma activation, interface formation, electrical functionality, reliability, and manufacturability. The effects of plasma-induced physical etching, defluorination, radical generation, polar functionalization, weak-boundary-layer removal, and hydrophobic recovery are first discussed. Representative metallization routes are then reviewed, including direct physical vapor deposition, plasma-assisted electroless plating, plasma-induced grafting, metallic interlayers, ion implantation, and hybrid plasma-deposition processes. Particular attention is given to interface-strengthening mechanisms involving chemical bonding, mechanical interlocking, diffusion control, carbon-rich or graded transition regions, and interdiffusion. The key trade-offs among adhesion strength, conductor resistance, dielectric integrity, surface-modification stability, and mechanical or environmental reliability are further analyzed for electronic-substrate applications. Although metallic interlayers, ion implantation, and hybrid processes can provide more stable interfaces than plasma activation alone, challenges remain in controlling plasma-induced damage, surface aging, interfacial carbonization, and process reproducibility. Recent 2024–2026 studies further show that these interface technologies can translate into low-loss Cu/PTFE laminates, flexible circuits, integrated vacuum metallization stacks, and selectively patterned conductors. The relevance to low-power systems is therefore treated as one application context at the substrate/interconnect level rather than as evidence that PTFE metallization directly reduces circuit switching power.