Ion implantation effects on the characteristics of β-Ga2O3 epilayers grown on sapphire by MOCVD

Abstract

In this study, the Si-ions implantation technique with different doses from 1 × 1014 to 1 × 1015 cm−2 and dose energy 30, 40 and 50 keV was used to tune the electrical properties in unintentionally doped (UID) β-Ga2O3 epilayers grown on the sapphire substrates by metalorganic chemical vapor deposition (MOCVD). A high quality UID β-Ga2O3 epilayers were fabricated using the optimized growth parameters of MOCVD. The UID and Si-ions implanted β-Ga2O3 epilayers were examined and results were compared with the help of X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. Si-ions implantation parameters were also simulated by stopping and range of ions in matter software (SRIM) and actual Si-ions concentration was measured by secondary ions mass spectroscopy. The electrical properties of the implanted β-Ga2O3 epilayers were measured by transmission length method and Hall measurements. The sheet resistivity for the β-Ga2O3epilayers with Si-ion dose of 1 × 1014, 6 × 1014 and 1 × 1015 cm−2 were found as 2.047, 0.158 and 0.144 Ω cm, respectively measured by Hall measurements and the electron carrier concentrations for the above doses were 4.39 × 1018, 6.86 × 1018 and 7.98 × 1019 cm−3. From the above results, the ion implantation was demonstrated to effectively reduce the resistivity with the high carrier concentrations.