Spectroscopic Studies Of Defects In 200keV Electron Irradiated ?-Ga₂O₃ Wafers

?-Ga₂O₃is a new type of oxide semiconductor material with wide band gap,good optical properties,high breakdown voltage and radiation resistance,making it has great advantages in high-power,low-loss semiconductor devices.Electron irradiation can form oxygen vacancy(V_O)and oxygen interstitial(O_i)defects in?-Ga₂O₃crystals.However,the current research on?-Ga₂O₃defects mainly focuses on the defects formed during the growth process,while there are few studies on?-Ga₂O₃electron irradiation defects.This severely restricts the development of radiation control technology for?-Ga₂O₃device performance,and further affects the research and development of?-Ga₂O₃high power electronic devices.In this work,the?-Ga₂O₃wafers are irradiated by 200keV electrons,and then Raman spectroscopy and photoluminescence(PL)spectroscopy are used for characterization.By studying the temperature dependence and the laser power dependence of the Raman peak and the zero phonon line(ZPL)in the spectrum,and its distribution along the depth of the crystal,combined with the effect of annealing on the intensity of the Raman peak and ZPL.Reveal the defect structure corresponding to the ZPL,determine the structure and distribution of?-Ga₂O₃crystal irradiation defects,and provide theoretical guidance and technical support for the application of?-Ga₂O₃materials in the field of high-power electronic devices.The results are as follows:After 200keV electron irradiation,the Raman peak intensity enhance,position shift and FWHM broadening of?-Ga₂O₃crystals.This is because the radiation introduces intrinsic defects in the crystal.As the measurement temperature rises,the Raman peak shows red shift and FWHM broadening,and it has the greatest impact on the Raman peak in the high frequency region.Which shows that the temperature change is accompanied by intense[Ga O₄]tetrahedral bending and symmetrical tensile vibration,and shows that it has a greater impact on oxygen atoms.Along the depth of the crystal,the Raman spectrum began to return to the Raman spectrum of the unirradiated wafer,indicating that the damage to the crystal due to electron irradiation began to weaken.After annealing at 300??1000?,the Raman spectrum gradually returned to the Raman spectrum of the unirradiated wafer,indicating that annealing caused defects in the crystal to recombine.The?-Ga₂O₃wafer is irradiated with 200keV electrons,the 684nm,690nm and 697nm ZPL become strong and sharp.As the measurement temperature increases,the ZPL intensity is quenched,the peak position shifts,and the FWHM broadens.By comparing the Huang-Rhys factor,thermal quenching activation energy,thermal softening coefficient and other physical quantities,it is shown that the atomic structure of 697nm ZPL is more"hardness"than that of690nm.In the laser excitation process,684nm,690nm and 697nm ZPL are affected by both radiation recombination and Auger recombination.The ZPL intensity decreases along the depth of the crystal,and the attenuation coefficients of each ZPL are different.After annealing at 300??1000?,the690nm and 697nm ZPL began to weaken,indicating that O_idefects can move freely in the wafer during the annealing process and recombine with V_O.