  A detailed study of the influence of molecular beam epitaxial growth
conditions on the structural and magnetic characteristics of CuMnSb films on
lattice matched GaSb is presented. For a set of nine 40~nm thick layers, the Mn
and Sb fluxes are varied to produce material with different elemental
compositions. It is found that the layers grown under a relative Mn to Sb flux
ratio of $\Phi_{\text{Mn}}$/$\Phi_{\text{Sb}}=1.24\pm0.02$ are closest to the
stoichiometric composition, for which the N\'{e}el temperature ($T_\text{N}$)
attains its maximum values. Mn-related structural defects are believed to be
the driving contribution to changes in the vertical lattice parameter. Having
established the optimum growth conditions, a second set of samples with CuMnSb
layer thickness varied from 5 to 510 nm is fabricated. We show that for
sufficiently large thicknesses, the magnetic characteristics
($T_\text{N}\simeq62$ K, Curie-Weiss temperature $\Theta_\text{CW} = -100$ K)
of the stoichiometric layers do correspond to the parameters reported for bulk
samples. On the other hand, we observe a reduction of $T_\text{N}$ as a
function of the CuMnSb thickness for our thinnest layers. All findings reported
here are of particular relevance for studies aiming at the demonstration of
N\'{e}el vector switching and detection in this noncentrosymmetric
antiferromagnet, which have been recently proposed.
