Vibration compensation for high speed scanning tunneling microscopy

Low scanning speed is a fundamental limitation of scanning tunneling micros copes (STMs), making real time imaging of surface processes and nanofabrica tion impractical. The effective scanning bandwidth is currently limited by the smallest resonant vibrational frequency of the piezobased positioning s ystem (i.e., scanner) used in the STM. Due to this limitation, the acquired images are distorted during high speed operations. In practice, the achiev able scan rates are much less than 1/10th of the resonant vibrational frequ ency of the STM scanner. To alleviate the scanning speed limitation, this a rticle describes an inversion-based approach that compensates for the struc tural vibrations in the scanner and thus, allows STM imaging at high scanni ng speeds (relative to the smallest resonant vibrational frequency). Experi mental results are presented to show the increase in scanning speeds achiev able by applying the vibration compensation methods. (C) 1999 American Inst itute of Physics. [S0034-6748(99)00812-6].