Scanning probe microscopy characterisation of masked low energy implanted nanometer structures

In order to fabricate and characterise nanometer structures, silicon wafers were implanted with masks ranging from several mum down to 200 nm in later al dimensions. The masks were produced by an electron beam lithography, met al deposition and metal lift-off sequence. 10 keV As-75(+)-ions were implan ted to a fluence of 2.5 x 10(14) cm (2) to create nanometer-sized doped and undoped volumes. Characterisation of the ion-implanted patterns was carrie d out by etching away the metal masks and subsequently using atomic force m icroscopy (AFM) and scanning capacitance microscopy (SCM) images of the pat terns. The simultaneous AFM and SCM measurements gave sharp contrasts betwe en implanted and unimplanted regions, showing highly resistive swelled stru ctures. The swelling also showed structure with a concave shape for implant ed regions and a convex shape for unimplanted regions, which is most probab ly a result of damage evolution from the implantation. (C) 2001 Elsevier Sc ience B.V. All rights reserved.