Wide-range-adjusted threshold voltages for E-mode AlGaN/GaN HEMT with a p-SnO cap gate

Abstract

p-GaN cap layer has been recognized as a commercial technology to manufacture enhanced-mode (E-mode) AlGaN/GaN high electron mobility transistor (HEMT); however, the difficult activation of Mg doping and etching damage of p-GaN limit the further improvement of device performance. Thus, the more cost-effective cap layer has attracted wide attention in GaN-based HEMT. In this paper, p-type tin monoxide (p-SnO) was firstly investigated as a gate cap to realize E-mode AlGaN/GaN HEMT by both Silvaco simulation and experiment. Simulation results show that by simply adjusting the thickness (50 to 200 nm) or the doping concentration (3 × 10 17 to 3 × 10 18 cm −3 ) of p-SnO, the threshold voltage (V th ) of HEMT can be continuously adjusted in the range from zero to 10 V. Simultaneously, the device demonstrated a drain current density above 120 mA mm −1 , a gate breakdown voltage (V BG ) of 7.5 V and a device breakdown voltage (V B ) of 2470 V. What is more, the etching-free AlGaN/ GaN HEMT with sputtered p-SnO gate cap were fabricated, and achieved a positive V th of 1 V, V BG of 4.2 V and V B of 420 V, which confirms the application potential of the p-SnO film as a gate cap layer for E-mode GaN-based HEMT. This work is instructive to the design and manufacture of p-oxide gate cap E-mode AlGaN/GaN HEMT with low cost.

Research Progress and Development Prospects of Enhanced GaN HEMTs

“…Lukens et al reported a "first gate" selfaligning process using Mo as both the etched mask layer and the gate metal and found that the barrier degradation of the device did not occur after high-temperature annealing [45]. In view of the generally low breakdown voltage of p-GaN grid HEMTs, domestic and foreign researchers have continuously optimized and innovated the process or structure in recent years [46][47][48]. At present, the breakdown voltage is mainly improved by designing various field plate structures.…”

Effects of preparation parameters on growth and properties of β-Ga2O3 film

“…With the excellent physicochemical properties, the wide bandgap semiconductor materials (such as SiC, GaN, AlGaN) are very suitable for high-temperature, high-frequency, and high-power semiconductor devices including diodes, detectors, and high-power electronic devices. [1][2][3] However, these devices are rarely able to go out of the laboratory and enter into industrialization because of the high cost of fabrication. Therefore, to reduce the cost of wide bandgap semiconductor devices is necessary for their practical application.…”