A technique for preparing Si substrates in molecular‐beam epitaxy (MBE) systems devoted to III–V compound growth is described. A C‐ and O‐free Si surface is obtained on previously oxidized substrates using a HF solution etch. A (2×1) reconstructed surface with steps of monoatomic height is achieved with an atomic Si flux provided by a standard effusion cell, while the substrate is maintained at 600 °C for ∼10 min. The experimental results presented were obtained using Auger electron spectrometry and reflection high‐energy electron diffraction.