Rapid Planarization Method by Ultraviolet Light Irradiation for Gallium Nitride Using Platinum Catalyst
We have developed a chemical process for atomic planarization of gallium nitride (GaN) using a platinum catalyst and ultraviolet (UV) light irradiation. The process is mediated by a hydrolysis reaction catalyzed by platinum as a solid catalyst. Because the reaction occurs selectively from the step edges, a flat surface composed of a straight step-and-terrace structure is obtained. In the absence of UV light, owing to the low step edge density, the removal rate is quite slow, approximately 1 nm/h. In contrast, under UV light, etch pits are formed on the terraces by photo-electrochemical etching causing an increase in the step edge density. We achieved surface planarization with a removal rate of 9.6 nm/h assisted by irradiation with UV light.
Tojiro Aoyama, Hideki Aoyama, Atsushi Matsubara, Hayato Yoshioka and Libo Zhou
H. Asano et al., "Rapid Planarization Method by Ultraviolet Light Irradiation for Gallium Nitride Using Platinum Catalyst", Key Engineering Materials, Vols. 523-524, pp. 46-49, 2012