  We analyze the forced incompressible stationary Navier-Stokes flow in
$\mathbb{R}^n_+$, $n>2$. Existence of a unique solution satisfying a global
integrabilty property measured in a scale of tent spaces is established for
small data in homogenous Sobolev space with $s=-\frac{1}{2}$ degree of
smoothness. Moreover, the velocity field is shown to be locally H\"{o}lder
continuous while the pressure belongs to $L^p_{loc}$ for any $p\in (1,\infty)$.
Our approach is based on the analysis of the inhomogeneous Stokes system for
which we derive a new solvability result involving Dirichlet data in
Triebel-Lizorkin classes with negative amount of smoothness and is of
independent interest.
