Surface patterning of wide-gap semiconducting β-Ga 2 O 3 thin films by area selective crystallization via room-temperature excimer laser annealing and low toxic wet-etching processes

In the present study, we have developed a fully room-temperature and low toxic surface-patterning method for β-Ga 2 O 3 , where consists of the area selective laser-induced crystallization of amorphous Ga 2 O 3 thin films and acid-solution etching processes. Highly (−201)-oriented crystalline β-Ga 2 O 3 thin films with ~70 nm thickness on α-Al 2 O 3 (0001) substrates were obtained by a combination of room-temperature deposition process and the subsequent excimer laser annealing at a deep-ultraviolet wavelength of 248 nm. In conclusion, the area selective crystallized β-Ga 2 O 3 micropatterns were obtained by ultrasonic wet etching with 40% H 3 PO 4 aqueous solution to remove amorphous regions.