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Last name: MAHER
First name: Hassan
International audience
This paper reports on the fabrication of an enhancement-mode AlGaN/GaN metal-insulator-semiconductor-high electron mobility transistor with a new barrier epi-layer design based on double Al 0.2 Ga 0.8 N barrier layers separated by a thin GaN layer. Normally-off transistors are achieved with good performances by using digital etching (DE)...
Fluorine ion migration in normally-off AlN/GaN HEMTs fabricated by fluorine ion plasma implantation technology is evidenced. Devices under test are co-integrated into the OMMIC commercial D006GH/D01GH MMIC process, providing fluorine-free normally-on HEMTs. Gate reverse bias step-stress experiment at a drain fixed voltage of 0 V, carried out as...
This paper proposes a new technique to engineer the Fin channel in vertical GaN FinFET toward a straight and smooth channel sidewall. Consequently, the GaN wet etching in the TMAH solution is detailed; we found that the m-GaN plane has lower surface roughness than crystallographic planes with other orientations, including the a-GaN plane. The...
The paper explores the Deep Level Transient Fourier Spectroscopy (DLTFS) capabilities in characterizing electrically active traps in vertical GaN-on-GaN Schottky barrier diodes (SBDs). The capacitance-DLTFS (C-DLTFS) experiments reveal a prominent electron trap T2 at EC-0.56 eV with a density (NT2) of 8×10 14 cm-3 and a weak presence of another...
In this work, the physical and the electrical properties of vertical GaN Schottky diodes were investigated. Cathodo-luminescence (CL), micro-Raman spectroscopy, SIMS, and current-voltage (I-V) measurements were performed to better understand the effects of physical parameters, for example structural defects and doping level inhomogeneity, on...
We report on the fabrication of an enhancement mode p-GaN/AlN/GaN high electron mobility transistor with selective area sublimation under vacuum of the p-GaN cap layer. The GaN evaporation selectivity is demonstrated on the thin 2 nm AlN barrier layer. Furthermore, the regrowth of AlGaN is a major key to increase the maximum drain current in...
International audience
This work presents an innovative technology where GaN-based vertical and lateral devices are monolithically integrated. Indeed, this technology will enable to drive high-power switching devices (vertical GaN power FinFETs) using lateral GaN HEMTs with minimum losses and high stability. The main challenge of this technology is the electrical...
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International audience
In this paper, we report on the fabrication of a normally-off Al(Ga)N/GaN high electron mobility transistor with selective area sublimation under vacuum of the p type doped GaN cap layer. This soft method makes it possible to avoid damages otherwise induced by post processing with reactive ion etching techniques. The GaN evaporation selectivity...
N-doped homo-epitaxial GaN samples grown on freestanding GaN substrates have been investigated by micro-Raman spectroscopy. Quantitative analysis of the Eh2 and the A1(LO) modes' behavior has been performed while intentionally increasing the carrier density using silicon doping. We noticed that as the carrier concentration increases up to 1.8 ×...
In the present study, the selective sublimation of the p-GaN cap layer of Al(Ga)N/GaN HEMTs is developed to replace the commonly used dry etching with no risk of damage in the barrier layer in order to fabricate enhanced mode transistors. Thanks to this approach, enhancement-mode transistors are fabricated with a threshold voltage between 0 V...
In this work, measurements from cathodo-luminescence (CL), micro-Raman spectroscopy and currentvoltage I(V) have been coupled to assess the effects of physical parameters such as threading dislocations and effective doping level homogeneity on the electrical performances of vertical GaN Schottky diodes.
This paper reports comprehensive characterization of vertical GaN-on-GaN Schottky barrier diodes (SBDs) fabricated on free-standing GaN substrates. The GaN active layer properties are evaluated by atomic force microscopy (AFM), secondary-ion mass spectrometry (SIMS), micro-Raman spectroscopy, cathodoluminescence (CL), and deep-level transient...
The forward and reverse current transport mechanisms, temperature dependence of Schottky barrier height (SBH) and ideality factor, barrier inhomogeneity analysis, and trap parameters for Schottky barrier diodes (SBDs) fabricated on 4H-SiC, GaN-on-GaN and AlGaN/GaN epitaxial substrates are reported. High SBH is identified for Ni/4H-SiC (1.31 eV)...