Surface patterning of wide-gap semiconducting β-Ga₂O₃ thin films by area selective crystallization via room-temperature excimer laser annealing and low-toxic wet etching processes

Abstract In the present study, we have developed a fully room-temperature and low-toxic surface patterning method for β -Ga 2 O 3 , which consists of the area selective laser-induced crystallization of amorphous Ga 2 O 3 thin films and acid solution etching processes. Highly ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mn>2</mml:mn> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> 01)-oriented crystalline β -Ga 2 O 3 thin films with ∼70 nm thickness on α -Al 2 O 3 (0001) substrates were obtained through 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 through ultrasonic wet etching with 40% H 3 PO 4 aqueous solution to remove amorphous regions.