A formation method of a
semiconductor device comprises the steps of providing a substrate, wherein a grid structure is formed on the surface of the substrate;
etching to remove the
partial thickness of substrate at the two sides of the grid structure to form grooves; carrying out the oxidation treatment on the surfaces of the grooves to form oxidation films, and repairing the
crystal lattice damage on the surfaces of the grooves; removing the oxidation films to
expose the surfaces of the grooves; adopting an
epitaxy process to form the stress
layers filling the grooves. According to the present invention, before the stress
layers are formed, the oxidation treatment is carried out on the surfaces of the grooves, the materials having the
crystal lattice damage on the surfaces of the grooves are transformed into the oxidation film materials, and then the oxidation films are removed, so that the exposed
crystal lattices on the surfaces of the grooves are high in quality, and accordingly, the stress
layers of high quality and few defects are conducive to being formed, the stress actions of the stress layers in a channel region are larger, and a
driving current of the formed
semiconductor device is improved.