Semi-polarity gallium nitride epitaxial layer structure and preparation method

The invention provides a semi-polarity gallium nitride epitaxial layer structure and a preparation method. By inserting two silicon nitride layers including a first silicon nitride layer and a secondsilicon nitride layer among a first gallium nitride layer, a second gallium nitride layer and a third gallium nitride layer, crystal quality of semi-polarity surface gallium nitride can be improved greatly, and some lattice imperfections in the first gallium nitride layer, such as dislocation and stacking faults, are solved. Sequentially, the second silicon nitride layer is inserted into a plurality of micropores, thus, the lattice imperfections in the third gallium nitride layer can be reduced greatly, and crystal quality of the semi-polarity gallium nitride epitaxial layer structure is improved greatly. With the structure of two silicon nitride layers including the first silicon nitride layer and the second silicon nitride layer, the semi-polarity gallium nitride epitaxial layer structure can effectively stop th