Abstract: Provided are an epitaxial structure and a semiconductor chip applying same. The epitaxial structure comprises a quantum well structure, a P-type contact layer, and an electrode layer, which are stacked in sequence; the P-type contact layer comprises a first step part and a second step part that are disposed in a step shape, the second step part being closer to the quantum well structure relative to the first step part; the first step part and the second step part are filled with a first insulation part. By means of the described method, the anti-catastrophic optical mirror damage value of a semiconductor chip can be effectively improved.