导模法生长大尺寸高质量β-Ga2O3单晶

High-Quality and Large-Size β-Ga2O3 Single Crystals Grown by Edge-Defined Film-Fed Growth Method

以高纯Ga2O3为原料,使用自主设计的单晶生长炉,采用导模（EFG）法生长了2英寸（1英寸=2.54 cm）未掺杂的高质量β-Ga2O3单晶。研究了保护气氛对抑制Ga2O3原料高温分解速率的影响,对制备的β-Ga2O3单晶的晶体质量、位错和光学性能进行了测试和表征。结果表明,CO2保护气氛能够极大地抑制Ga2O3材料的高温分解,当CO2生长气压为1.5×105Pa时,Ga2O3的平均分解速率低于1 g/h。（100）面β-Ga2O3单晶的X射线衍射（XRD）摇摆曲线测试结果表明,其半高宽低至29 arcsec,表明晶体具有较高的质量;对晶体（100）面进行了位错腐蚀,结果显示其位错密度较低,约为4.9×10^4cm^-2;傅里叶变换红外光谱仪测试结果显示,β-Ga2O3单晶在紫外、可见光透过率达到80%以上。

The 2-inch（ 1 inch = 2. 54 cm） undoped high-quality β-Ga2O3 single crystal were prepared in a self-designed single-crystal growth furnace with edge-defined film-fed growth（ EFG） method using high-purity Ga2O3 as the raw material. The effect of protective atmosphere on the decomposition rate of Ga2O3 raw material at high temperature was studied. The crystal quality,dislocation and optical properties of the prepared β-Ga2O3 single crystal were measured and characterized. The results show that the CO2 protective atmosphere can greatly inhibit the decomposition of Ga2O3 materials at high temperature.When the growth pressure of CO2 is 1. 5 × 105 Pa,the average decomposition rate of Ga2O3 is less than1 g/h. The X-ray diffraction（ XRD） rocking test results of β-Ga2O3 single crystal（ 100） crystal plane show that the full width at half maximum（ FWHM） is as lower as 29 arcsec,which indicates the high quality of the as-grown crystal. The dislocation density of the sample is lower,which is about 4. 9 ×10^4 cm^-2 by measuring the dislocation on（ 100） crystal plane. In addition,the test results of the Fourier transform infrared spectrometer indicate that the transmittances of β-Ga2O3 single crystal through both UV and visible light are above 80%.