ELECTROCHEMICAL SCANNING-TUNNELING-MICROSCOPY AND ATOMIC-FORCE MICROSCOPY OBSERVATIONS ON SI(111) IN SEVERAL SOLUTIONS

Electrochemical scanning tunneling microscopy (ESTM) and atomic force microscopy (AFM) images of hydrogen-terminated Si(111) in several solutions have been studied tt, evaluate the performance of the AFM method. In dilute H2SO4 solution, the overall features of AFM images were similar to those of ESTM images, suggesting that both images reflect the topography of the bare H-Si(111) surface. However, AFM images in ultrapure water and in dilute NaOH solution were successfully obtained, while ESTM images were not. These results indicate that AFM is a powerful method for studying topographic change of Si in solutions during the wet cleaning process.