Abstract: A method of manufacturing micro devices includes: preparing a III-nitride epitaxial structure including a p-type III-nitride layer, an n-type III-nitride layer on the p-type III-nitride layer, a AlxIII_others1-xN layer on the n-type III-nitride layer, and an undoped III-nitride layer on the AlxIII_others1-xN layer; forming a photoresist layer on the III-nitride epitaxial structure to contact the undoped III-nitride layer; patterning the photoresist layer; performing a first plasma etching process to the III-nitride epitaxial structure through the patterned photoresist layer to form a trench in the etched III-nitride epitaxial structure, in which the trench extends from the etched photoresist layer at least to the AlxIII_others1-xN layer; and performing a second plasma etching process to the etched III-nitride epitaxial structure until the etched III-nitride epitaxial structure is cut into a plurality of micro devices and a top surface of the etched AlxIII_others1-xN layer is exposed.

Abstract: A method of manufacturing micro devices includes: preparing a GaN-based epitaxial structure including a p-type GaN layer, a n-type GaN layer on the p-type GaN layer, and an undoped GaN layer on the n-type GaN layer; forming a photoresist layer on the GaN-based epitaxial structure with the undoped GaN layer contacting the photoresist layer; patterning the photoresist layer; performing a plasma etching process to the GaN-based epitaxial structure through the patterned photoresist layer until the patterned photoresist layer is completely removed, such that a plurality of mesas are formed on the etched GaN-based epitaxial structure, in which a height of the mesas is at least 1.0 ?m; and continuing to perform the plasma etching process until the undoped GaN layer is completely removed and the etched GaN-based epitaxial structure is cut into a plurality of micro devices.