Blue light-emitting diodes with a roughened backside fabricated by wet etching

The InGaN-based light-emitting diodes (LEDs) with a roughened patterned backside on the N-face GaN surface were fabricated through a crystallographic etching process to increase light-extraction efficiency. After laser decomposition, laser scribing, and a lateral crystallographic wet etching process at the GaN/Al(2)O(3) interface, stable crystallographic etching planes were formed as the GaN {1011} planes that included an angle with the top GaN (0001) plane measured at 58 degrees. The GaN buffer layer acted as the sacrificial layer for the laser decomposition process and the lateral wet etching process with a 26 mu m/min etching rate. The LED with the inverted pyramidal N-face GaN surface close to the GaN/Al(2)O(3) interface has a larger light-scattering process than the conventional LED. The light-output power of the LED with the backside roughened surface had a 47% enhancement when measured in LED chip form.