| Ga2O3,as a new type of ultra-wide band gap semiconductor material,has attracted people’s attention,andβ-Ga2O3 has been widely studied.However,in the existing reports,high-qualityβ-Ga2O3 single crystal epitaxial films are mostly prepared on sapphire,magnesium oxide,magnesium aluminate and other substrates.However,because the above substrates are insulators,the preparation process is relatively complicated,the cost is high,and the thermal conductivity is poor,which is not conducive to the preparation of power electronic devices.Si substrate can solve the above problems.First of all,the Si substrate itself is conductive and has good thermal conductivity.Secondly,the large-size single crystal Si wafer is easier to obtain and the crystal quality is higher,which will be beneficial to the preparation and market promotion ofβ-Ga2O3 high-power devices.In this paper,gallium oxide films were deposited on different substrates by RF magnetron sputtering.In order to improve the crystalline quality of thin films,the effects of seed layer and post-annealing process on the properties of gallium oxide thin films were studied,and finally the preparation and growth of high-qualityβ-Ga2O3 thin films on single crystal Si substrate was realized.The main contents are as follows:（1）Gallium oxide thin film was grown on sapphire substrate with matching crystal lattice.The effect of annealing temperature on the crystal quality of the films was studied.It was found that 800℃was the best annealing temperature for gallium oxide thin film.Then,in order to further improve the crystal quality,before growing gallium oxide thin films,we deposited a gallium oxide seed layer and annealed it at high temperature.The effects of seed layer thickness and annealing temperature on the thin films were studied.Finally,it was found that adding a 9 nm seed layer and annealing it at 700℃could obtain gallium oxide thin films with the best crystal quality,which laid a foundation for the preparation of Si-based gallium oxide thin films.（2）Gallium oxide films were grown on Si substrates with large lattice mismatch.Through previous research,we found that gallium oxide films with high crystalline quality can be obtained by seed layer and annealing process on sapphire substrate.Therefore,we also studied the effects of seed layer and annealing process on gallium oxide thin films on Si substrate.XRD,SEM,XPS,TEM and other characterization methods were used for analysis.Finally,we found that when the seed layer thickness is 9 nm,annealed at 700℃in air,the crystalline layer thickness is 160 nm,and annealed at 800℃in air,gallium oxide films with high crystalline quality can be obtained on Si substrate.On this basis,we successfully prepared a Si-based gallium oxide ultraviolet detector. |
