Multi-channel tri-gate normally-on/off AlGaN/GaN MOSHEMTs on Si substrate with high breakdown voltage and low ON-resistance

Abstract

In this work, we present multi-channel tri-gate AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOSHEMTs) for high-voltage applications. A heterostructure with multiple AlGaN/GaN layers was used to form five parallel two-dimensional-electron-gas (2DEG) channels to reduce the ON-resistance (R ON ), simultaneously modulated by the 3-dimensional trigate electrodes. The tri-gate is a unique technology to control the multi-channels, providing enhanced electrostatics and device performance, and, in turn, the multi-channels are exceptionally suited to address the degradation in drain current (I D,max ) caused by the tri-gate. With a tri-gate width (w) of 100 nm, normally-on multi-channel tri-gate transistors presented 3Â-higher maximum drain current (I D,max ), 47%-smaller R ON , as well as 79%-higher maximum transconductance (g m,max ), as compared to counterpart single-channel devices. Using the channel depletion through the tri-gate sidewalls, normally-off operation was also achieved by reducing w below the sidewall depletion width (w dep ), resulting in a positive threshold voltage (V TH ) of 0.82 V at 1 lA/mm. The devices presented a high breakdown voltage (V BR ) of 715 V, which reveals a promising future platform for high-voltage low-R ON GaN transistors. Published by AIP Publishing.

Multi-Channel Tri-Gate GaN Power Schottky Diodes With Low ON-Resistance

“…Firstly, it can lead to novel lateral power devices with much smaller RON and much higher current ratings for a given device area, thanks to its ultra-low Rs, down to 37 Ω/sq [19], combined with the superior voltageblocking capabilities of tri-gates and slanted tri-gates [1], [27]. Secondly, this approach can be easily extended for high-voltage normally-on/off multi-channel tri-gate GaN transistors [34], nanoscale in-plane-gate transistors, and many other devices and applications, yielding a promising platform for future efficient electronic devices. To unleash the full potential of multichannel tri-gate technology, an intensive and coupled material research and device engineering are required, which opens tremendous opportunities for future studies in novel epitaxy structures and device designs.…”

Efficient Microchannel Cooling of Multiple Power Devices With Compact Flow Distribution for High Power-Density Converters

“…The increasingly tight constraints on size and weight for these power electronics systems has pushed a broad range of innovations, spanning from wide band-gap (WBG) semiconductor devices [2] to new converter topologies [3]. WBG devices, employing gallium nitride (GaN) and silicon carbide (SiC), have a small footprint and high power density owing to their low specific onresistance and high breakdown electric field [4], [5], enabling a compact converter design. Additionally, GaN high electron mobility transistors (HEMTs) can operate at higher frequencies, enabling the use of smaller passive components which further reduces the converter volume.…”

“…However, due to the high thermal conductivity of silicon, the conduction component is negligibly small (<0.01 K/W). For this reason, the thermal resistance of the cold-plate is modeled as only a convective thermal resistance, Rconv, as expressed in (5). h is the heat transfer coefficient and A is the total surface area of the microchannels.…”

“…h is the heat transfer coefficient and A is the total surface area of the microchannels. Using the fin model, previously described in [20], [28]- [30], an expression was derived for the convective thermal resistance, as shown in (5). The geometry of a microchannel is described by the channel width and fin width.…”

Embedded Microchannel Cooling for High Power-Density GaN-on-Si Power Integrated Circuits

“…Ongoing developments in lateral GaN power devices, such as improved epi-layers, field plates and tri-gates, are resulting in reduced specific onresistance for a given voltage rating [2], [3]. Especially with the introduction of new power transistors and diodes based on GaN superlattice heterostructures, recently proposed in the literature [4], [5], major improvements in the Vbr/Ron figure of merit has been realized. The subsequent reduction in device size in combination with the lateral nature of GaN power HEMTs enable monolithic integration of multiple components into compact power ICs with considerably lower parasitic inductance [6], thus allowing much higher frequency operation as well as high power density.…”