Atomic force microscopy and friction force microscopy of Langmuir–Blodgett films for microlithography

Abstract

We describe the study of microlithography of a thin chromium film on a quartz plate by an atomic force microscope (AFM) and a friction force microscope (FFM). The scratching of Langmuir–Blodgett (LB) films of ω-tricosenoic acid deposited on the chromium films was carried out by scanning an AFM tip under a high normal force of ∼5×10−8 N. The scratched depth was measured by a topographic AFM image recorded by scanning with a new tip under a low normal force of 1×10−8 N. The surface properties of the scratched surfaces created in the multilayered LB films were studied by the FFM. From (1) the wear patterns observed on the scratched surface of the multilayer and (2) the high resistance against scratching of the single monolayer observed by AFM and FFM, it was concluded that the first monolayer always remained even after scratching under the high normal force. Etching resistance of the chromium surfaces covered with LB films with a various number of monolayers was also studied by measuring elapsed times required for complete etching. A drastic change in the etching resistance was observed between the bare or the single monolayer covered chromium films and the multilayer covered ones.