Dense arrays of horizontal carbon nanotubes (CNTs) connected between two metallic electrodes and either supported on a silicon dioxide layer or suspended above a third gate electrode constitute a basic building block to achieve CNT-based electronic devices such as sensors, interconnect lines or micro-electromechanical systems. Despite the recognized potential of CNTs, their adoption as alternative materials is postponed mainly due to integration issues at wafer-scale. A reliable integration scheme, based on in-situ CNT growth by chemical vapor deposition (CVD), totally compatible with full wafer processing was previously proposed by our team to manufacture multi-criteria resistive and resonating gas sensors. Resistive sensors were fabricated via the successful integration of supported, dense horizontal few-walled CNT membranes on 100 mm wafers. Here, the suspension of the membranes is experimentally demonstrated by etching the under-lying silicon dioxide in a buffered HF solution followed by a critical point drying. Moreover, the elaboration of a huge number of similar CNT membranes at the wafer-scale constitutes a real asset to study and optimize the impact of post-growth processes on the CNT electrical performances: top metallization, encapsulation and suspension processes are investigated as critical steps for CNT-based device fabrication.
Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2014: Graphene, CNTs, Particles, Films & Composites
Published: June 15, 2014
Pages: 9 - 12
Industry sector: Advanced Materials & Manufacturing
Topics: Carbon Nano Structures & Devices, Graphene & 2D-Materials