Study on Electrochemical Corrosion and CMP of GaN in Different Oxidation Systems

With the rapid development of the third generation semiconductor materials, the chemical mechanical polishing rate and surface quality of GaN have been a research hot-spot. By changing the concentration of oxidant and the pH of the solution, the corrosion characteristics of gallium nitride material were studied. The oxidant used in the experiment were hydrogen peroxide, sodium hypochlorite and potassium permanganate. Next, according to the results of electrochemical experiments, chemical mechanical polishing experiments were designed and accomplished with colloidal silica based slurry. Finally, the surface morphology of gallium nitride wafer was measured. The experimental results showed that MRR of GaN was as high as 404.6 nm h −1 by using the sodium hypochlorite as the oxidant under UV, with surface roughness (Ra) of 1.61 nm; MRR of GaN was 380.3 nm h −1 by using H 2 O 2 as the oxidant under UV, with surface roughness (Ra) of 0.065 nm.