AlGaN/GaN high electron mobility transistor grown on GaN template substrate by molecule beam epitaxy system
POSTER
Abstract
In this study, AlGaN/GaN high electron mobility transistor (HEMT) structure was grow on GaN template substrate radio frequency plasma assisted molecular beam epitaxy (MBE) equipped with an EPI UNI-Bulb nitrogen plasma source. The undoped GaN template substrate was grown on c-sapphire substrate by metal organic vapor phase epitaxy system (MOPVD). After growth of MOVPE and MBE, the samples are characterized by double crystal X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (SEM), atomic force microscopy (AFM), and Hall effect measurements. We found that the RMS roughness of template substrate play the major role in got the high value of mobility on AlGaN/GaN HEMT. When the roughness was lower than 0.77 nm in a 25 $\mu$m x 25 $\mu$m area, the mobility of HEMT at the temperature of 77 K was over 10000 cm$^{2}$/Vs.
*The authors would like to acknowledge Epistar corporation for supply GaN template substrates and financial support from the National Science Council of Republic of China.