SHARPENED ELECTRON-BEAM DEPOSITED TIPS FOR HIGH-RESOLUTION ATOMIC-FORCE MICROSCOPE LITHOGRAPHY AND IMAGING

We employ the vibrating tip of an atomic force microscope as a lithogr aphic tool to mechanically pattern a thin photoresist layer covering a GaAs-AlGaAs heterostructure. High aspect ratio electron beam deposite d tips, additionally sharpened in an oxygen plasma, are used to minimi ze the dimensions of the fabricated quantum electronic devices. The fa brication parameters of the tips and the sharpening process are invest igated. With these ultrasharp tips we are able to produce lines and ho les with periods down to 9 nm in photoresist. In addition, the very sh arp tips yield substantial improvements in the imaging mode. (C) 1995 American Institute of Physics.