We present numerical Monte Carlo results for the stationary-state propertie
s of KPZ-type growth in two-dimensional surfaces, by evaluating the finite
size scaling (FSS) behavior of the second and fourth moments W-2 and W-4 an
d the skewness W-3 in the Kim-Kosterlitz (KK) and body-centered solid-on-so
lid (BCSOS) models. Our results agree with the stationary state proposed by
Lassig. The roughness exponents W(n)similar to L-alpha n obey power counti
ng alpha(n)=n alpha, and the amplitude ratios of the moments are universal.
They have the same values in both models: W-3/W-2(1.5) = - 0.27(1) and W-4
/W-2(2) = + 3.15(2). Unlike in one dimension, the stationary-state skewness
is not tunable, but a universal property of the stationary-state distribut
ion. The FSS corrections to scaling in the KK model are weak and a converge
s well to the Kim-Kosterlitz-Lassig value alpha = 2/5. The FSS corrections
to scaling in the BCSOS model are strong. Naive extrapolations yield a smal
ler value alpha similar or equal to 0.38(1), but are still consistent with
alpha = 2/5 if the leading irrelevant corrections to the FSS scaling expone
nt are of order y(ir) similar or equal to - 0.6(2). [S1063-651X(99)00503-6]
.