Effects of Dissolved Oxygen on Anodic Etching of n-Type GaN Films Using a Sodium Hydroxide Electrolyte

Abstract

Anodic etching, of high quality GaN films grown by metalorganic vapor phase deposition (MOCVD) on a sapphire substrate using a sodium hydroxide (NaOH) electrolyte is reported on. Factors such as the concentration of dissolved oxygen in the NaOH electrolyte affecting the GaN surface are discussed. It is found that the reduction of the concentration of dissolved oxygen in the NaOH electrolyte accelerates the rate of anodic etching of GaN films. The effect of decreasing the concentration of dissolved oxygen in the electrolyte is to reduce the amount of gallium hydroxide formed on the GaN surface. It seems that the concentration of dissolved oxygen in the NaOH electrolyte plays an important role in the anodic etching of n-GaN films.