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Last name: RENNESSON
First name: Stephanie
International audience
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...
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...
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...
This letter reports on the demonstration of microwave power performance at 40 GHz on AlGaN/GaN high-electron mobility transistor grown on silicon (111) substrate by molecular beam epitaxy. A maximum dc current density of 1.1 A.mm(-1) and a peak extrinsic transconductance of 374 mS.mm(-1) are obtained for 75-nm gate length device. At V-DS = 25...
The performance of gallium nitride transistors is still limited by technological problems often related to defects and traps. In this work, virgin AlGaN/AlN/GaN HEMTs exhibiting an anomalous DC behavior accompanied by frequency dispersion in the microwave range, both in the transconductance and output conductance, are analyzed. This anomalous...
Ultra-violet semiconductor lasers have numerous applications for optical storage, biochemistry, sterilization or optical interconnects. However the usual design of deep UV-emitting ridge lasers relies on complex buffer layers or expensive substrates for the growth of the nitride heterostructures [1]. Moreover microlaser and nanophotonic devices...
The slab waveguide geometry is attracting more and more interest in the field of polaritonics. Waveguide polaritons are obtained when an excitonic transition and a slab guided mode are brought in the strong coupling regime, in strong analogy with cavity polaritons in Fabry-Perot resonators. Waveguide polaritons have been first demonstrated in...
The performance of GaN transistors is still limited by physical and fabrication problems, mainly related to different kinds of traps. In this work, virgin transistors reveals strong low frequency dispersion both in the transconductance and output conductance, that we attribute to the presence of traps in the GaN channel and the ohmic contacts....
III-nitride-on-silicon L3 and H2 photonic crystal cavities with resonances down to 315 nm and quality factors up to 1085 at 337 nm have been demonstrated. The reduction of quality factor (Q) with decreasing wavelength is investigated. Besides the QW absorption below 340 nm a noteworthy contribution is attributed to the residual absorption...
On-chip microlaser sources in the blue constitute an important building block for complex integrated photonic circuits on silicon. We have developed photonic circuits operating in the blue spectral range based on microdisks and bus waveguides in III-nitride on silicon. We report on the interplay between microdisk-waveguide coupling and its...
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The polariton emission in a microcavity is usually measured from the surface, and little is known about the actual role of guided modes below the light cone in air; these can couple to the exciton transition and give rise to additional polaritons branches, creating thereby a polaritons leak channel, and can further collect part of the...
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The main interest of group-III-nitride nanophotonic circuits is the integration of active structures and laser sources. A photonic platform of group-III-nitride microdisk lasers integrated on silicon and emitting in the blue spectral range is demonstrated. The active microdisks are side-coupled to suspended bus waveguides, and the coupled...
International audience
From the characterization of structure equivalent loss tangent under different conditions (bias and temperature) obtained through propagation constant and characteristic impedance extraction of CPW line, we propose a coherent analysis of the properties of an AlN/Si interface featured with a GaN on Si HEMT technology.
International audience
International audience
International audience
Here, we experimentally and theoretically clarify III-V/Si crystal growth processes. Atomically resolved microscopy shows that monodomain three-dimensional islands are observed at the early stages of AlSb, AlN, and GaP epitaxy on Si, independently of misfit. It is also shown that complete III-V/Si wetting cannot be achieved in most III-V/Si...
In this work, we experimentally and theoretically clarify the III-V/Si crystal growth processes. Atomically-resolved microscopy shows that mono-domain 3D islands are observed at theearly stages of AlSb, AlN and GaP molecular beam epitaxy on Si, independently of strain. It is also shown that complete III-V/Si wetting cannot be achieved in most...