Material and device issues of AlGaN/GaN HEMTs on silicon substrates
Selected material and device issues related to the performance of AlGaN/GaN HEMTs on (111) Si substrates are reported. It is shown that these devices can sustain significantly higher dc power (16W/mm) than those grown on sapphire. Consequently smaller degradation in the device performance at higher temperatures (up to 400 C) is demonstrated. Photoionisation spectroscopy reveals trap level of 1.85eV, additional to two another levels found before in GaN-based HEMTs prepared on sapphire. Thus, AlGaN/GaN HEMTs on Si substrates demonstrate the viability of this technology for commercial application of high power rf devices.
si substrates gan-based hemts iv characteristics