Light emitting diode epitaxial structure based on aluminum gallium nitride material and its manufacturing method

A method for manufacturing a light emitting diode epitaxial structure based on an aluminum gallium nitride (AlGaN) material, the method comprising:

• forming a buffer layer of aluminum nitride disposed on a substrate;
• forming a first layer of n-type AlGaN disposed on the buffer layer;
• forming an active layer disposed on the first layer, wherein the active layer comprises AlGaN;
• forming a p-type AlGaN layer disposed on the active layer;
• forming a second layer of n-type AlGaN disposed on the p-type AlGaN layer along an epitaxial growth direction;
• and
• forming a coarsened structure disposed on the second layer.

An apparatus comprising:

• a light emitting diode epitaxial structure comprising:
• a substrate;
• a buffer layer of aluminum nitride disposed on the substrate;
• a first layer of n-type aluminum gallium nitride (AlGaN);
• an active layer comprising AlGaN, wherein a center emission wavelength of the active layer comprising AlGaN ranges between 255 nanometers and 340 nanometers;
• a p-type AlGaN;
• a second layer of n-type AlGaN disposed above the p-type AlGaN along an epitaxial growth direction, wherein a coarsened structure is on a surface of the second layer of n-type AlGaN, wherein the second layer of n-type AlGaN has a thickness between 0.8 and 3 times of the center emission wavelength of the active layer comprising AlGaN;
• and
• an epitaxial layer comprising a gallium nitride (GaN) layer contained between an epitaxial layer of the p-type AlGaN and an epitaxial layer of the second layer of n-type AlGaN, and the epitaxial layer comprising the GaN layer has an energy band width smaller than an energy bandwidth of the epitaxial layer of the p-type AlGaN and an energy bandwidth of the epitaxial layer of the second layer of n-type AlGaN.