MEDJDOUB , F

In this paper, a performance comparison between sub-micron thick AlGaN/GaN and AlN/GaN HEMT devices are reported. Various gate lengths have been employed in order to analyze the impact on DC and RF performances. Electrical characteristics of these structures for 100 nm gate length show a higher maximum drain current, extrinsic transconductance...

International audience

International audience

International audience

GaN high electron mobility transistors (HEMT) are becoming the mainstream for high frequency and power switching applications. Devices and circuits based on these emerging materials are more suited to operate at higher voltages and temperatures than Si-based devices owing to their superior physical properties. Recently, AlGaN/GaN based high...

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AlxGa1-xN heterojunction FETs (HFETs) have been an eye catcher for high voltage power electronics with its potential to outperform the predecessors by virtue of high critical breakdown field of the material, which can be tuned by varying Al mole-fraction. In this work, we demonstrate Al0.23Ga0.77N channel HFETs on bulk AlN with a maximum drain...

GaN high electron mobility transistors (HEMT) are becoming the mainstream for high frequency and power switching applications. On the other hand, Ultra-Wide Band Gap (UWBG) materials such as AlN that has a bandgap of 6.2 eV are attracting attention for pushing the limits of high voltage power devices. In this work, we report on AlGaN/GaN-on-AlN...

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MBE has several advantages for the epitaxy of GaN-based heterostructures. More specifically, by controlling the interface between the AlN buffer layer and the silicon substrate, ammonia-MBE allows to grow innovative structures on silicon. Epitaxy on silicon necessarily requires a demonstration of scaling-up on large wafers used by the...

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Despite a high lateral breakdown voltage above 10 kV for large contact distances and a breakdown field of 5 MV cm −1 for short contact distances, an Al 0.9 Ga 0.1 N/GaN heterostructure with an 8 nm strained GaN channel grown on an AlN/sapphire template suffers from a low and anisotropic mobility. This work deals with a material study to...

High power electronics using wide bandgap materials are maturing rapidly, and significantmarket growth is expected in a near future. Ultra wide bandgap materials, which have an even largerbandgap than GaN (3.4 eV), represent an attractive choice of materials to further push the performancelimits of power devices. In this work, we report on the...

GaN and SiC materials and their device technology have matured and become commerciallyavailable. Fundamental material properties will soon limit the performance. Consequently, a novelbreakthrough in power electronics performance requires a new generation of materials. In this frame,the so-called ultra-wide-bandgap (UWBG) materials that have...

International audience

International audience

In this paper, we present the fabrication and Direct Current/high voltage characterizations of AlN-based thin and thick channel AlGaN/GaN heterostructures that are regrown by molecular beam epitaxy on AlN/sapphire. A very high lateral breakdown voltage above 10 kV was observed on the thin channel structure for large contact distances. Also, the...

The rapidly increasing power demand, downsizing of power electronics and material specific limitation of silicon has led to development of AlGaN/GaN heterostructures. Commercial GaN power devices are best available for radio frequency (RF) and high voltage switching applications. Emerging Al x Ga 1-x N channel based heterostructures are...

In this paper, AlN-based HEMTs on silicon are demonstrated using NH3-MBE. The spirit is to get the highest 2DEG density theoretically achievable in nitrides while keeping thin barrier thickness, which is mandatory to achieve high frequency performances. To do that, the strategy consists in growing a relaxed AlN ...

Using NH3-MBE, AlN-based HEMTs on silicon are demonstrated for the first time. Ultra-thin heterostructures typically consist of 200 nm-thick AlN buffer, followed by 20 nm-thick strained GaN channel, 3-10 nm-thick AlN barrier. 2DEG densities (Ns) are measured as a function of AlN barrier thicknesses. Value as high as 2.7x10 13 cm-2 is measured...

Using micro-Raman spectroscopy on MOCVD slightly n-doped GaN on sapphire structures (1.5 x 10$^{15}$ cm$^{-3}$ – 6.5 x 10$^{15}$ cm$^{-3}$), we report a method to dissociate biaxial stress contribution from n carrier concentration contribution in A1(LO) Raman peak position. For all characterized samples, the main Raman peaks A$_1$(LO) and...

International audience

The rapidly increasing power demand, downsizing of power electronics and material specific performance limitation of silicon has led to the development of AlGaN/GaN heterostructures for high power applications. In this frame, emerging AlxGa1-xN channel based heterostructures show promising features for next generation of power electronics. In...