Vertical GaN MISFET for chip-on-chip high speed laser driving applications
Electron. Lett., vol. 56, no. 20, pp. 1084-1086 (2020).
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In this work, the authors developed vertical gallium nitride metal-insulator-semiconductor field-effect transistors (GaN MISFETs) for direct chip-on-chip assembly with gallium arsenide-based broad area distributed Bragg reflector diode laser. The intention of this work had been to provide a high-speed driver solution having extremely small parasitic inductive loops. It is shown that devices manufactured on ammonothermal substrates have large conduction current density above 1.7 kA/cm2, specific on-state resistance as low as 2.1 mΩ·cm2 and on-state sheet resistance of 18.6 Ω·mm. It is further shown that scaling these devices to large gate periphery chips is possible. Finally, a low inductance vertical GaN MISFET on laser diode integration assembly is realised on an AlN ceramic board using a transistor chip with 142 mm gate width and 305 mΩ on-state resistance. The arrangement enables 3.6 ns laser pulses at an emission wavelength at 904 nm and a peak optical power of 4 W.
Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, 12489 Berlin, Germany