Laser Roughening for LED Light Extraction Efficiency

The patent replaces the chemical etching process with a laser-based ablation process. The laser directly ablates the GaN surface to create roughness features without requiring chemical etchants, thereby eliminating the need for complex sealing procedures while achieving the same light extraction enhancement

The patent introduces a laser as an intermediary tool between the desired surface roughness and the GaN material. The laser serves as a mediator that transfers energy to ablate the surface without requiring direct contact with corrosive chemicals, thus avoiding the side effects of traditional etching methods

The patent employs periodic pulsed laser irradiation to ablate the GaN surface. By using short, repeated laser pulses instead of continuous chemical exposure, the process achieves surface roughness in a fraction of the time required for traditional etching, significantly reducing batch processing time

The laser ablation process rapidly removes material through high-energy pulses, skipping through the lengthy chemical reaction time required by traditional etchants. This allows the process to rush through the roughening step in seconds rather than minutes

The patent converts the potentially harmful laser energy into a beneficial tool for selective surface modification. By carefully controlling laser parameters, the harmful high-energy radiation is directed only at the GaN surface to create roughness, while leaving other materials unaffected, thus converting a potentially damaging force into a precise manufacturing tool

The laser ablation process applies energy locally and selectively to the GaN surface regions that require roughness. This localized action ensures that only the intended areas are modified, while surrounding materials such as metals, photoresist, and silicon oxide remain unaffected by the processing