Heteroepitaxy immediate to thermodynamical equilibrium is investigated for liquid phase epitaxy of Ge0.85Si0.15on Si(111). Below and beyond the critical thickness for strain relaxation, the GeSi layer grows in a two‐dimensional mode. The critical thickness agrees well with mechanical equilibrium considerations. Strain relaxation is found to take place by the confined formation of misfit dislocations directly at the Ge0.85Si0.15/Si interface. We do not observe half‐loop formation at the layer surface. The misfit dislocations (b=1/6⟨112⟩) form regular networks, which are buried under a structurally perfect relaxed GeSi layer virtually free of threading dislocations.