Nanometer-scale lithography of the Langmuir-Blodgett films with atomic force microscope

The Langmuir-Blodgett (LB) films as a resist for scanning probe microscope (SPM) lithography have been studied extensively. The poly(methylphenyl methacrylate) (PMPMA) LB films were prepared and fabricated by atomic force microscopy (AFM) lithography. The induced bias voltage, scanning speed and developing conditions are very important for the high resolution AFM lithography. When the exposure was carried out at the bias voltage of -25 V, the protruding lines appeared in the exposed regions. This result provided evidence of a negative resist phenomenon due to the bond formation to build longer-chain polymer molecules which decrease the dissolution rate in the appropriate developer compared to that of the unexposed molecules. Preoptimized LB films at the various conditions exhibit 120 nm line resolution. (C) 1998 Elsevier Science S.A. All rights reserved.