We have investigated the impact of relative gate position between source and drain on the DC and RF characteristics for AlGaN/GaN high electron mobility transistors. Devices with fixed source drain separation (LSD) of 5 μm, width (W) of 2×50 μm and gate length (LG) of 200 nm are fabricated and characterized. The relative position of the gate is varied with constant LSD. The value of saturation drain current (IDS,sat) and maximum transconductance (gm,max) change from 740 mA/mm and 168 mS/mm for gate to source separation (LGS) of 3.8 μm to 1071 mA/mm and 245 mS/mm for LGS = 0.25 μm, respectively. The corresponding breakdown voltage (Vbr) significantly improves from 65 V (for LGS = 3.8 μm) to 189 V (for LGS = 0.25 μm). The unity current gain frequency (fT) is observed to remain constant at 55GHz for all positions of the gate. However, output power density is found to increase from 3.8 to 5.1 W/mm for the same relative change in the gate position.

中文翻译：

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相对栅极位置对高性能 AlGaN/GaN HEMT 直流和射频特性的影响


我们研究了源极和漏极之间的相对栅极位置对 AlGaN/GaN 高电子迁移率晶体管的 DC 和 RF 特性的影响。制造并表征了源漏间距 (LSD) 固定为 5 μm、宽度 (W) 为 2×50 μm、栅极长度 (LG) 为 200 nm 的器件。门的相对位置随 LSD 恒定而变化。对于 3.8 μm 的栅源分离 (LGS)，饱和漏极电流 (IDS,sat) 和最大跨导 (gm,max) 值从 740 mA/mm 和 168 mS/mm 变为 1071 mA/mm 和 245 mS/mm。 LGS = 0.25 μm 时分别为 mm。相应的击穿电压 (Vbr) 从 65 V（LGS = 3.8 μm）显着提高至 189 V（LGS = 0.25 μm）。据观察，对于栅极的所有位置，单位电流增益频率 (fT) 均保持恒定在 55GHz。然而，对于栅极位置的相同相对变化，输出功率密度从 3.8 W/mm 增加到 5.1 W/mm。