Effect of Al Doping on the Optical Properties of β-Ga2O3 Thin Films
In recent years,semiconductor devices are developing towards high heat dissipation,high breakdown field strength and low energy consumption,so the ultra-wide band semiconductor material β-Ga2O3 has a broad application prospect.However,effective doping is the basis for realizing β-Ga2O3 devices.In this paper,Ga2O3/Al/Ga2O3/Al/Ga2O3 composite structure is experimentally prepared by magnetron sputtering,and the Al atoms are thermally diffused into the film by high-temperature annealing at the same time,so as to form Al-doped β-Ga2O3 thin film.Then,the laser zone melting method was used to melt and recrystallize the film area to further enhance the doping quality.The Al-doped β-Ga2O3 thin films were tested and characterized in terms of crystal properties,impurity content and optical properties.The experimental results show that:Al doping basically does not change the crystal structure of β-Ga2O3 thin films;the impurity content is gradually enhanced as the sputtering time of the Al layer becomes longer;in terms of the optical properties,the ultraviolet(UV)absorptivity of the films is 40％and 50％when the Al sputtering time is 5 and 10 s,and the UV absorption of the Al-doped β-Ga2O3 thin films is gradually enhanced with the increase of Al sputtering time;the light absorption of β-Ga2O3 thin film is close to 90％when the Al sputtering time is 300 s;and the low concentration of Al doping leads to the narrowing of the band gap width ofβ-Ga2O3 thin film.
β-Ga2O3 thin filmAl dopingmagnetron sputteringGa2O3/Al/Ga2O3/Al/Ga2O3 composite structurelight absorptionoptical band gap
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