Optimizing light extraction efficiency for an led wafer

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

• ascertaining an optimized surface roughness value for an LED wafer, wherein the optimized surface roughness value corresponds to maximum optical power for LEDs on the LED wafer;
• performing a first roughening process to the LED wafer, wherein the first roughening process is performed under a first set of process conditions;
• obtaining an actual surface roughness value of the LED wafer after the first roughening process is performed;
• determining whether the actual surface roughness value is within an acceptable range relative to the optimized surface roughness value;
• and
• performing a second roughening process to the LED wafer if the actual surface roughness is not within the acceptable range, wherein the second roughening process is performed under a second set of process conditions.

A method of fabricating a light-emitting diode (LED) wafer, comprising:

• determining a target surface morphology for the LED wafer, wherein the target surface morphology yields a maximum light output for LEDs on the LED wafer;
• etching the LED wafer to form a roughened wafer surface;
• investigating, using a laser scanning microscope, an actual surface morphology of the LED wafer after the etching;
• and
• repeating the etching one or more times if the actual surface morphology differs from the target surface morphology beyond an acceptable limit, wherein the etching is repeated by adjusting one or more etching parameters.