Gallium nitride light-emitting diodes and a study of etching techniques

In the recent years Light Emitting Diodes of impressive longevity and high efficiency have been produced. Gallium Nitride in particular is used in the manufacture of Blue Light Emitting Diodes because it is a direct band gap semiconductor which can be alloyed with AlN and InN allowing band gap energies to range from 1.9eV to 6.2eV, which allows the emission of short wavelengths like that of blue light. A new structure for a GaN blue LED has been proposed. The difficulty faced in wet etching GaN resulted in the study of viable dry etching techniques. This study has looked into the Reactive Ion Etching of Gallium Nitride in Sulphur Hexafluoride. The use of Laser Ablation as an alternative method of etching GaN has been studied in detail. N-type contacts have been deposited on the etched surface and their specific contact resistivities have been measured for different samples under different conditions.