FRAYSSINET , Éric

Les travaux portent sur la réalisation technologique d'un HEMT AlGaN/GaN normally-off avec une grille à barrière P-GaN. Des résultats de simulation ont montré que la tension de seuil de cette structure peut atteindre une valeur supérieure à 2 V et qu'elle est liée à la profondeur de gravure de la couche d'AlGaN. Nous avons développé une recette...

A new normally-off AlGaN/GaN HEMT structure is proposed. The regrowth of a P-GaN layer on the AlGaN/GaN heterostructure after the gate recess allows the achievement of the enhancement mode. A shift in the threshold voltage to positive values has been proved through simulation results. A precise control of the etch depth for the gate recess is detailed.

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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...

Blue (Ga,In)N-based light-emitting diodes (LEDs) grown on a Si(111) substrate by metal-organic vapor phase epitaxy are transferred on a flexible tape after the Si substrate removal. Their optical and thermal behaviors are measured and compared to those of regular LEDs on Si. The light output power of the flexible LEDs is increased due to a...

This paper reports on the kink effect observed in InAlN/GaN high electron mobility transistors. Electrical characterizations were carried out to point out the influence of this phenomenon on transistor behaviour. It is demonstrated that the kink effect is directly correlated to shallow traps located under the conduction band. A model is...

We report on the fabrication and characterization of flexible blue thin-film micro-LED grown by MOVPE.Two approaches are explored to replace laser lift-off for the micro-LED device liberation from the growth substrate:the release of the micro-LED structures assisted by quasi-van der Waals epitaxy using an interfacial h-Bn layer; andthe...

In this work, we describe the main features of selective area growth (SAG) of GaN by molecular beam epitaxy (MBE) using ammonia. Different schemes such as growth into micrometer and nanometer size windows in Si3N4 dielectric masks and mesa structures etched on GaN or Silicon substrate are studied.

Un nouveau concept d'interrupteur de puissance HEMT en GaN présentant la fonctionnalité « normally-off » est expérimentalement validé. L'introduction d'une couche P-GaN suffisamment dopée (autour de 2 x 10 18 cm-3) au sein de la couche buffer GaN NID, en-dessous de l'électrode de grille et sous l'interface AlGaN / GaN, permet d'obtenir une...

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In the present paper, we describe the development of new AlN seed layers obtained by combining molecular beam epitaxy and low temperature physical vapour deposition (magnetron sputtering). It is shown that it is possible to grow thick AlN seed layers with a good in-plane crystal ordering. GaN based structures on silicon can then be regrown with...

In the present paper, we describe the development of new AlN seed layers obtained by combining molecular beam epitaxy and low temperature physical vapour deposition (magnetron sputtering). It is shown that it is possible to grow thick AlN seed layers with a good in-plane crystal ordering. GaN based structures on silicon can then be regrown with...