Preparation method of AlGaN-based nano-porous distributed Bragg reflector

The invention relates to the technical field of semiconductor materials, in particular to a preparation method of an AlGaN-based nano-porous distributed Bragg reflector. The preparation method comprises the following steps: alternately depositing a silicon-doped AlGaN layer and an undoped AlGaN layer on the surface of an AlN buffer layer to obtain a composite AlGaN layer; fixedly connecting electrode metal to at least part of the surface of the composite AlGaN layer to obtain a processed electrode; carrying out electrochemical etching treatment on the electrode by adopting an acidic electrolyte to obtain a porous AlGaN sample; the porous AlGaN sample is soaked in an acid solution, then the treated porous AlGaN sample is dried, and the AlGaN-based nano-porous distributed Bragg reflector is obtained; the etching bias voltage of electrochemical etching is greater than 30V; the method overcomes the defects of low refractive index difference, large lattice mismatch and high strain accumulation of the AlGaN layer i