Laminar-type gratings as soft x-ray beam splitters for interferometry are presented. Gold-coated grating beam splitters with $1000\text{lines}/\mathrm{mm}$ are designed for grazing incidence operation at $13.9\mathrm{nm}$ . They are routinely fabricated using electron beam lithography and ion etching techniques. The laminar grating is measured to have almost equal absolute efficiencies of about 20% in the zeroth and $-1$ st orders, which enables a fringe visibility up to 0.99 in the interferometer. The discrepancy of the grating profiles between the optimized theoretical and the experimental results is analyzed according to the comparison of the optimized simulation results and the measurement realization of the grating efficiencies. By a precise control of the grating profile, the grating efficiency in the $-1$ st order and the fringe visibility could be improved to 25% and 1, respectively.