Investigation On Ga₂O₃ And Mg Doped Thin Films Fabricated By Rf Magnetron Sputtering Method

Because of the features of wide direct bandgap of 5.0eV,?-Ga₂O₃ is viewed as a kind of promising semiconductor material.As transparent conductive oxide?TCO?materials,Ga₂O₃ thin films have attracted intensive investigations due to its wide applications in ultraviolet?UV?photodetectors,gas sensors,photoluminescence,and etc.There are many methods to fabricate Ga₂O₃ thin films,e.g.,Pulsed laser deposition?PLD?,chemical vapor deposition?CVD?,metal organic chemical vapor deposition?MOCVD?,molecular beam epitaxy?MBE?and magnetron sputtering method?MS?.As is well known,films fabricated by MS method has a series of advantages such as good compactness,good adhesion,low substrate temperature,high deposition speeding,suitable for large area deposition and manufacture on a large scale.So radio frequency?RF?magnetron sputtering method is used in this article,and the detailed study is shown as following:Using the purity of 99.999%Ga₂O₃ as the target material,Ga₂O₃ thin films are deposited on high-resistivity silicon and sapphire by RF magnetron sputtering technology.In order to study the effects of growth conditions such as sputtering power,deposition pressure,substrate temperature,substrate materials and deposition time,the Ga₂O₃ thin films are characterized by Stylus Profiler,XRD,uv-vis,SEM and AFM.The study shows that,with the growth conditions of the sputtering power is 100or 150W,deposition pressure is 0.5Pa,the substrate temperature is 300?and deposition time is more than 2 hours,the large granular Ga₂O₃ thin films can be obtained both on the high-resistivity silicon and sapphire substrate.With the deposition growth conditions above,Ga₂O₃ thin films were deposited on high-resistivity silicon and sapphire by RF magnetron sputtering technology,and then annealed at O₂ atmosphere for 2 hours.In order to study the effects of annealing temperature,the Ga₂O₃ thin films are characterized by Stylus Profiler,XRD,AFM and UV-vis.The result shows that the ideal annealing temperature is 1000?.With the purity of 99.99%Ga₂O₃ and MgO as the target material,the MgO doped Ga₂O₃ thin films are deposited on high-resistivity silicon and sapphire by RF magnetron sputtering technology,during which,alternative sputtering method is used.And then the thin films are annealed at O₂ atmosphere for 2 hours.In order to study the effects of Mg concentration and the effects of annealing temperature,the MgO doped Ga₂O₃ thin films are characterized by Stylus Profiler,XRD,UV-vis and PL.The result shows that,both the structure and the optical properties are influenced by the Mg concentration,and the ideal Mg doped Ga₂O₃ can be obtained when annealing temperature is 1000?.