The GaN-based materials have successfully developed on short-wavelength laser diodes (LDs), light-emitting diodes (LEDs) and ultraviolet photodetector. Indium-tin-oxide (ITO) thin films have been studied extensively in the optoelectronic industry because they combine unique transparent and conducting properties. ITO thin film is a highly degenerate n-type semiconductor which has a low electrical resistivity of 2-4¡Ñ10-4 £[cm. The low resistivity value of ITO films is due to a high carrier concentration because the Fermi level (EF) is located above the conduction level (EC). The degeneracy is caused by both oxygen vacancies and substitutional tin dopants created during film deposition. Furthermore, ITO is a wide band gap semiconductor visible and near-IR region of the electromagnetic spectrum. Due to these unique properties, ITO has been used in a wide range of applications. In this study, we deposited InSnO film on n-type and p-type GaN by thermal evaporator to overcome the confrontation between brightness and current spreading in optoelectronic devices. According to the experimental results, we study the mechanisms and characteristics of InSnO on GaN. Photoenhanced wet etching of GaN has recently been identified as a means of greatly improving the chemical reactivity of GaN at room temperature. Ultraviolet illumination is used to generate electron-hole pairs at the semiconductor surface, which enhance the oxidation and reduction reactions within an electrochemical cell. We have previously studied a photocnhanced wet etching process n-type GaN using HeCd laser illumination and KOH solution. In this study, etch rates of approximately 300nm/min were obtained.