  We show both theoretically and experimentally that scanning tunneling
spectroscopy (STS) images of semiconductor quantum dots may display clear
signatures of electron-electron correlation. We apply many-body tunneling
theory to a realistic model which fully takes into account correlation effects
and dot anisotropy. Comparing measured STS images of freestanding InAs quantum
dots with those calculated by the full configuration interaction method, we
explain the wave function sequence in terms of images of one- and two-electron
states. The STS map corresponding to double charging is significantly distorted
by electron correlation with respect to the non-interacting case.
