IMAGING STEEP, HIGH STRUCTURES BY SCANNING FORCE MICROSCOPY WITH ELECTRON-BEAM DEPOSITED TIPS

Probe tips for the scanning force microscope (SFM) were fabricated using the electron beam of a scanning electron microscope (SEM) to deposit thin carbon microtips on the end of commercially available silicon nitride SFM cantilevers. The microtips are made by aligning the electron beam directly down the axis of the original, pyramidal tip, and allowing carbon deposits to grow. In SEM micrographs the tips are approximately conical at their points, with typical end diameters of about 30 nm and cone angles of about 15-degrees, and become cylindrical further down the shank, with diameters on the order of 0.1-mu-m. SFM images of steep, high test gratings which were made using these tips are accurately imaged, especially compared to the original, unaltered tips without a deposited microtip. Short tips were found to be quite robust: it is possible to scan at high speeds without damaging them, and, by applying high force, create small-scale furrows in metal-coated sample surfaces, again without damaging the tips.