The invention provides a preparation method of a
semiconductor structure, and particularly relates to the technical field of semiconductors. The preparation method of the
semiconductor structure comprises the steps that a substrate is provided, the substrate comprises a substrate body, a pad
oxide layer, a first pad
nitride layer and a plurality of groove isolation structures, the pad
oxide layer covers the portion, between every two adjacent groove isolation structures, of the substrate body, the first pad
nitride layer covers the surface of the pad
oxide layer, and the groove isolation structures are at least partially exposed out of the substrate body; removing the first pad
nitride layer; performing
ion implantation on the substrate; carrying out
thinning treatment on the pad oxide layer; forming a second pad nitride layer on the surfaces of the trench isolation structure and the pad oxide layer;
etching the second pad nitride layer, the pad oxide layer and the substrate by taking the patterned
photoresist as a
mask so as to form an opening in the substrate; and performing
thermal oxidation treatment on the substrate in the opening to form an oxide layer. By adopting the preparation method of the
semiconductor structure, the speed of a
semiconductor device can be increased, and the
circuit performance of the
semiconductor device can be improved.