Spatially resolved dopant profiling of patterned Si wafers by bias-appliedphase-imaging tapping-mode atomic force microscopy

Tapping-mode atomic force microscopy was used to spatially resolve areas of different doping types on Si wafers patterned by photolithography and subs equent ion implantation. Application of a direct current dc bias between ca ntilever and sample during measurement induced a change in the tapping-mode phase contrast depending on the dopant type of the scanned sample area. Th is allowed the direct identification of areas of different doping types. Ad ditional measurements on Au samples demonstrate a direct correlation betwee n bias-induced Coulomb force and resulting phase change allowing the conclu sion that the observed phase contrast results from dc bias-induced band ben ding changes. (C) 1999 American Institute of Physics. [S0003-6951(99)02910- 1].