Light-emitting diode fabrication method

A method of fabricating a light-emitting diode, comprising:

• providing a substrate;
• growing over the substrate a low-temperature AlxGa1-xN (0≦x≦1) buffer layer, an undoped gradient GaN layer, an N-type gradient GaN layer, a multiple quantum-well layer, an AlxGa1-xN (0≦x≦1) electron blocking layer and a P-type layer;
• wherein after growth of the buffer layer, set the growth pressure from high to low and temperature and rotation rate from low to high to realize change from three-dimensional growth to two-dimensional growth of the GaN structure layer before growth of the multiple quantum-well layer by changing critical layer thickness over the substrate surface and lateral and vertical growth rate and Si is doped at position proximal to the multiple quantum-well layer to form an undoped gradient GaN layer and an N-type gradient GaN layer with gradient growth mode;
• during later chip fabrication, dividing the epitaxial wafer over the etched N-type platform into chip grains and immersing them in chemical solutions for wet etching;
• and forming an inverted pyramid structure with rough side wall over the GaN structure layer to improve light-emitting efficiency.