Growth of carbon nanotubes by thermal and plasma chemicalvapour deposition processes and applications inmicroscopy

Abstract

Single-walled carbon nanotubes (SWNTs) are grown from a methanefeedstock by thermal chemical vapour deposition (CVD). Anethylene-hydrogen plasma generated in an inductively coupledplasma reactor primarily yields multi-walled carbon nanotubes and thicker fibres. In both cases, an ironcatalyst layer and an aluminium underlayer are deposited by ionbeam sputtering onto silicon wafers for the growth of carbonnanotubes (CNTs). The plasma process provides well-aligned multi-wallednanofibres useful for fabrication of electrodes and sensors andfurther tip functionalization whereas thermal CVD produces a matof SWNT ropes. In addition, CNTs grown at the tipsof silicon cantilevers are demonstrated to be ideal for high-resolution imaging of biological samples and simulated Marsdust grains using atomic force microscopy.