Semiconductor structure, self-supporting gallium nitride layer and preparation method thereof

The invention particularly relates to a semiconductor structure, a self-supporting gallium nitride layer and a preparation method thereof. The preparation method comprises the steps of providing a substrate, forming a silicon dioxide layer on the substrate, forming a patterned mask layer on the upper surface of the silicon dioxide layer, wherein a plurality of openings are formed in the patterned mask layer, performing heat treatment on the obtained structure in a mixed atmosphere of hydrogen and ammonia gas so as to form a silicon nitride layer at the bottom of the opening, and forming a first gallium nitride layer in the opening and on the upper surface of the patterned mask layer. According to the preparation method of the semiconductor structure in the embodiment, the silicon dioxide layer is formed on the substrate, the silicon nitride layer is formed on the upper surface of the silicon dioxide layer exposed out of the opening in the patterned mask layer through heat treatment, and nucleation is performe