  We study spontaneous breaking of scale invariance in the large N limit of
three dimensional $U(N)_\kappa$ Chern-Simons theories coupled to a scalar field
in the fundamental representation. When a $\lambda_6(\phi^\dagger\cdot\phi)^3$
self interaction term is added to the action we find a massive phase at a
certain critical value for a combination of the $\lambda_6$ and 't Hooft's
$\lambda=N/\kappa$ couplings. This model attracted recent attention since at
finite $\kappa$ it contains a singlet sector which is conjectured to be dual to
Vasiliev's higher spin gravity on $AdS_4$. Our paper concentrates on the
massive phase of the 3d boundary theory. We discuss the advantage of
introducing masses in the boundary theory through spontaneous breaking of scale
invariance.
