  We report room temperature scanning tunneling microscopy and spectroscopy
study of bilayer graphene prepared by mechanical exfoliation on SiO$_2$/Si
surface and electrically contacted with gold pads using a mechanical mask. The
bulk conductivity shows contribution from regions of varying electron density
indicating significant charge inhomogeneity. Large scale topographic images
show ripple like structures with a roughness of $\sim$1nm while the small scale
atomic resolution images show graphite-like triangular lattice. Local dI/dV-V
tunnel spectra have an asymmetric V-shape with the minima location showing
significant spatial variation indicating inhomogeneity in electron density of
order 10$^{11}$ cm-2. The minima in spectra at a fixed location also shifts
linearly with the gate voltage with a slope consistent with the field induced
carrier density.
