A novel high breakdown voltage and high switching speed GaN HEMT with p-GaN gate and hybrid AlGaN buffer layer for power electronics applications*

Abstract

A novel p-GaN gate GaN high-electron-mobility transistor (HEMT) with an AlGaN buffer layer and hybrid dielectric zone (H-HEMT) is proposed. The hybrid dielectric zone is located in the buffer and composed of horizontal arranged HfO2 zone and SiN x zone. The proposed H-HEMT is numerically simulated and optimized by the Silvaco TCAD tools (ATLAS), and the DC, breakdown, C–V and switching properties of the proposed device are characterized. The breakdown voltage of the proposed HEMT is significantly improved with the introduction of the hybrid dielectric zone, which can effectively modulate the electric field distribution in the GaN channel and the buffer. High breakdown voltage of 1490 V, low specific on-state resistance of 0.45 mΩ⋅cm2 and high Baliga’s figure of merit (FOM) of 5.3 GW/cm2, small R on Q oss of 212 mΩ⋅nC, high turn-on speed 627 V/ns and high turn-off speed 87 V/ns are obtained at the same time with the gate-to-drain distance L gd of 6 μm.

Enhancing the Self-Heating Capability of AlGaN/GaN HEMT Gadgets with Fourth-Generation Semiconductor Components

“…GaN HEMT devices are simulated with Silvaco TCAD software, and Figure 1 displays conventional HEMT devices [6] . The base material is a 2.45 ȝm SiC layer, and it has a 50 nm AIN nucleation layer on the substrate, which serves to buffer lattice misalignment and thermal stress between the substrate and buffer, thereby creating a good separation and buffering effect [7][8][9][10][11] .…”

Improving Performance and Breakdown Voltage in Normally-Off GaN Recessed Gate MIS-HEMTs Using Atomic Layer Etching and Gate Field Plate for High-Power Device Applications

“…The fabricated normally-off AlGaN/GaN MIS-HEMT with a recessed gate structure was grown on a 6 in commercial Si substrate by MOCVD, which consisted of the 1 nm GaN cap layer, a 25 nm Al 0.25 Ga 0.75 N barrier layer, a 1 nm AlN interlayer, a 300 nm undoped GaN channel layer, and a 4 µm AlGaN buffer layer [ 35 , 36 ], as shown in Figure 1 a. The normally-off MIS-HEMT with a recessed gate process started with mesa isolation, which was performed by the ICP-RIE to etch a specific region.…”

Enhancement of Breakdown Voltage in p-GaN Gate AlGaN/GaN HEMTs With a Stepped Hybrid GaN/AlN Buffer Layer

“…Duan et al proposed a depletion-mode AlGaN/GaN HEMTs with a partial GaN cap, which applied the electric field modulation effect to reshape the surface electric field and two dimensional electronic gas (2DEG) distributions [19]. A novel p-GaN HEMT with a hybrid AlGaN buffer is proposed to improve the BV and decrease the Ron,sp, which can effectively modulate the electric field distribution in the channel and the buffer [20]. Recently, the AlN buffer layers is routinely employed to improve the confinement of 2DEG and make the electric field redistribution, which would further improve the BV because of its large bandgap energy of 6.2 eV and high polarization field [21][22][23][24].…”