This letter reports on the improvement of the large-signal W-band power performance of nitrogen-polar gallium nitride deep recess high electron mobility transistors with the addition of a 40-nm-thick ex-situ silicon nitride passivation layer deposited by plasma enhanced chemical vapor deposition. The additional passivation improves the dispersion control allowing the device to be operated at higher voltages. Continuous-wave load pull measurements performed at 94 GHz on a $2\times 37.5\,\,\mu \text{m}$ transistor demonstrated an improvement in the peak power-added efficiency (PAE) to 30.2% with an associated output power density of 7.2 W/mm at 20 V drain bias. Furthermore, at 23 V, a new record-high W-band power density of 8.84 W/mm (663 mW) was achieved with an associated PAE of 27.0%.

中文翻译：

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SiN 钝化 N 极 GaN 深凹槽 HEMT 的 W 波段功率性能

这封信报告了氮极性氮化镓深凹高电子迁移率晶体管的大信号 W 波段功率性能的改进，增加了 40 nm 厚的异位氮化硅钝化层，该钝化层通过等离子体增强化学沉积气相沉积。额外的钝化改善了色散控制，允许器件在更高的电压下运行。在 94 GHz 频率下对 $2\times 37.5\,\,\mu \text{m}$ 晶体管进行的连续波负载牵引测量表明，峰值功率附加效率 (PAE) 提高至 30.2%，并具有相关的输出功率在 20 V 漏极偏压下的密度为 7.2 W/mm。此外，在 23 V 时，实现了 8.84 W/mm (663 mW) 的新的创纪录的 W 波段功率密度，相关的 PAE 为 27.0%。