Temperature mapping of Al0.85In0.15N/AlN/GaN high electron mobility transistors through micro-photoluminescence studies

Jean-François Carlin, Eric Feltin, Marcus Gonschorek, Nicolas Grandjean, Marcel Py, Dobri Simeonov
2009
Article

Résumé

Crack-free lattice-matched Al0.85In0.15N/GaN heterostructures were grown on sapphire substrates with barrier thicknesses up to 100 nm which exhibit very high polarization-induced electron sheet density (>2.5 x 10(13) cm(-2)) located at the heterointerface. These layers have been further processed as high electron mobility transistors (HEMTs). Optical characterization of these structures was carried out by photoluminescence and microphotoluminescence (mu PL) for different biased voltages. The insertion of an InGaN back-barrier unambiguously reveals that spatially direct optical recombinations occur within the AlInN alloy. Since the GaN excitonic bandgap is very sensitive to local temperature changes, the mu PL technique allows mapping very precisely the actual local temperature distribution in biased HEMT devices. For a gate length of 1.5 mu m temperatures up to 1130 K were found at a drain-source voltage of 20 V thus indicating the presence of a hot phonon bath.

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https://infoscience.epfl.ch/record/152848?ln=fr

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Temperature mapping of Al0.85In0.15/AlN/Gan high electron mobility transistors through micro-photoluminescence studies

Jean-François Carlin, Eric Feltin, Marcus Gonschorek, Nicolas Grandjean, Marcel Py, Dobri Simeonov

EDP Sciences2009

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Evaluation of AllnN/GaN HEMTs on sapphire substrate in microwave, time and temperature domains

Jean-François Carlin, Eric Feltin, Marcus Gonschorek, Nicolas Grandjean, Marcel Py

AllnN/GaN high electron mobility transistors (HEMTs) on sapphire substrate have yielded a maximum drain current density of 1.26 A/mm with a current gain cutoff and maximum oscillation frequencies about 26 and 40 GHz, respectively, for a 0.25 mu m gate length device. Pulsed characterisations indicate absence of the virtual gate effect and reveal that the drain current dispersion is mainly due to thermal effects. Temperature stress experiments up to 800 degrees C indicate that surface and hetero-interface are inherently stable. The reasons for the behaviour are discussed.

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Chargement

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Chargement

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