Fabrication and characterization of transparent conductive Sn-doped β-Ga_2O_3 single crystal

摘要

Transparent conductive Sn-doped β-Ga_2O_3 single crystal with high crystallinity was successfully fabricated as a substrate for the growth of GaN-based compounds. Sn-doped β-Ga_2O_3 single crystals were grown using a floating zone (FZ) method, and the properties of electrical conductivity, optical transmit-tance, and crystallinity were characterized to optimize the growth condition. It was found that these properties are controlled by the Sn doping concentration, and the specimen for 32 ppm Sn-doped β-Ga_2O_3 single crystal was optimized to satisfy these properties simultaneously, i.e. the substrate with the internal optical transmittance of above ～85 % in the visible region, the electrical resistivity of 4.27x10~(-2) Ωcm, the carrier density of 2.26x10~(18) cm~(-3), and the FWHM of X-ray rocking curve of 43 arcsec was obtained.