This invention discloses a
patterned substrate and its fabrication method, as well as an epitaxial
wafer for a light-emitting
diode (LED), relating to the field of
semiconductor optoelectronic devices. The
patterned substrate includes a substrate body, a
metal reflective layer, and multiple pyramidal protrusions. The substrate body has a first surface and a second surface disposed opposite to each other; the
metal reflective layer covers the first surface; the multiple pyramidal protrusions are uniformly distributed on the
metal reflective layer; each pyramidal protrusion includes a first AlN layer and a SiO2 layer sequentially stacked on the metal reflective layer. Implementing this invention can improve the luminous efficiency of the LED.