IEEE Electron Device Letters · 2006 · 100 citations · 15 references
SemiconductorsDevice ModelingElectrical EngineeringElectronic DevicesMetal GateEngineeringPhysicsSemiconductor TechnologyNanoelectronicsElectronic EngineeringAlgan SurfaceApplied PhysicsThreshold VoltageMicroelectronicsSemiconductor Device
Enhancement-mode <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$hboxSi_3hboxN_4/hboxAlGaN/GaN$</tex> metal–insulator–semiconductor HFETs (MISHFETs) with a 1- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$muhboxm$</tex> gate footprint are demonstrated by combining <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$hboxCF_4$</tex> plasma treatment technique and a two-step <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$hboxSi_3hboxN_4$</tex> deposition process. The threshold voltage has been shifted from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$-$</tex> 4 [for depletion-mode HFET] to 2 V using the techniques. A 15-nm <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$hboxSi_3hboxN_4$</tex> layer is inserted under the metal gate to provide additional isolation between the gate Schottky contact and AlGaN surface, which can lead to reduced gate leakage current and higher gate turn-on voltage. The two-step <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$hboxSi_3hboxN_4$</tex> deposition process is developed to reduce the gate coupling capacitances in the source and drain access region, while assuring the plasma-treated gate region being fully covered by the gate electrode. The forward turn-on gate bias of the MISHFETs is as large as 7 V, at which a maximum current density of 420 mA/mm is obtained. The small-signal RF measurements show that the current gain cutoff frequency <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(f_T)$</tex> and power gain cutoff frequency <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(f_max)$</tex> are 13.3 and 23.3 GHz, respectively.
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30-W/mm GaN HEMTs by Field Plate Optimization
Yifeng Wu, A. Saxler, M. Moore et al. · IEEE Electron Device Letters · 2004 · 1.1K citations
Wide-bandgap Semiconductor, Electrical Engineering, Engineering +13