Surface Functionalization for Conductivity Improvement by Metal Atomic Layer Deposition

摘要

Atomic layer deposition (ALD) is a thin film deposition method employing self-saturated surface reactions. Since ALD has several superior properties for nanoscale device fabrications, such as excellent conformality, large area uniformity, and process compatibility over the conventional thin film deposition methods, it has been widely applied for various high technology applications from semiconductor to display devices. Due to the surface reaction mechanism, ALD can be an effect route to change and modify surface properties with precise controllability in other applications. In this work, we utilized ALD as a tool for surface property modification, in particular, two examples were introduced, improvement conductivity of graphene and organic textiles. Ideally, graphene has high conductivity due to its unique atomic structure, however, it is not achievable in real system because of inevitable formation of defects during synthesis process which deteriorates the conductivity. Pt was selectively formed on the defect sites of chemically-synthesized graphene layer by ALD to improve the low conductivity of graphene, and Pt-decorated graphene was applied to transparent conducting heater system. Fabrication of conductive textiles is important to enable wearable electronics. Inspired from the conventional dyeing technology, we coat textiles with ALD Pt and Ru through organic-inorganic hybridization in atomic level. A capacitive type pressure sensor was fabricated by using the highly conductive ALD-modified textile fibers, and applied to seat sensor for vehicle. The ideas in these two examples could be also applied to other applications which require surface modifications and conductivity improvement without significant change of original properties.