  We present polarization resolved Raman scattering study of surface vibration
modes in the topological insulator Bi$_2$Se$_3$ single crystal and thick films.
Besides the four Raman active bulk phonons, we observed four additional modes
with much weaker intensity and slightly lower energy than the bulk
counterparts. Using symmetry analysis, we assigned these additional modes to
out-of-plane surface phonons. Comparing with first principle calculations, we
conclude that the appearance of these modes is due to $c$-axis lattice
distortion and van der Waals gap expansion near the crystal surface. Two of the
surface modes at 60 and 173 cm$^{-1}$ are associated with Raman active $A_{1g}$
bulk phonon modes, the other two at 136 and 158 cm$^{-1}$ are associated with
infrared active bulk phonons with $A_{2u}$ symmetry. The latter become Raman
allowed due to reduction of crystalline symmetry from $D_{3d}$ in the bulk to
$C_{3v}$ on the crystal surface. In particular, the 158 cm$^{-1}$ surface
phonon mode shows a Fano lineshape under resonant excitation, suggesting
interference in the presence of electron-phonon coupling of the surface
excitations.
