  We study (2+1)-dimensional single step model (SSM) for crystal growth
including both deposition and evaporation processes parametrized by a single
control parameter $p$. Using extensive numerical simulations with a relatively
high statistics, we estimate various interface exponents such as roughness,
growth and dynamic exponents as well as various geometric and distribution
exponents of height clusters and their boundaries (or iso-height lines) as
function of $p$. We find that, in contrary to the general belief, there exists
a critical value $p_c\approx 0.25$ at which the model undergoes a roughening
transition from a rough phase with $p<p_c$ in the Kardar-Parisi-Zhang (KPZ)
universality to a smooth phase with $p>p_c$, asymptotically in the
Edwards-Wilkinson (EW) class. We validate our conclusion by estimating the
effective roughness exponents and their extrapolation to the infinite-size
limit.
