  We carried out a finite-size scaling analysis of the restricted
solid-on-solid version of a recently introduced growth model that exhibits a
roughening transition accompanied by spontaneous symmetry breaking. The dynamic
critical exponent of the model was calculated and found to be consistent with
the universality class of the directed percolation process in a symmetry-broken
phase with a crossover to Kardar-Parisi-Zhang behavior in a rough phase. The
order parameter of the roughening transition together with the string order
parameter was calculated, and we found that the flat, gapped phase is
disordered with an antiferromagnetic spin-fluid structure of kinks, although
strongly dominated by the completely flat configuration without kinks. A
possible interesting extension of the model is mentioned.
