Novel Al_0.75Ga_0.25N/Al_xGa_1−xN/Al_0.75Ga_0.25N/AlN metal-oxide-semiconductor heterostructure field-effect transistors (MOS-HFETs) with symmetrically-graded widegap Al_xGa_1−xN channel (x $=\,\,0.75 \to 0.25 \to 0.75$ ) grown on a SiC substrate are investigated. Al₂O₃ was devised as the gate dielectric by using a non-vacuum ultrasonic spray pyrolysis deposition (USPD) technique. Device characteristics with respect to different etch depths of the source/drain recesses were studied. For a 2- $\mu \text{m}$ gate length ( $L_{G}$ ), the present widegap V-shape-channel MOS-HFET has shown improved maximum drain-source current density ( $I_{DS, max}$ ) of 299.3 A/mm at ${V_{DS}} = 20$ V, $I_{DS}$ density at $V_{GS} = 0$ V ( $I_{DSS0}$ ) of 153.9 mA/mm, on/off-current ratio ( $I_{on}$ / $I_{off}$ ) of 1.4 $\times 10^{7}$ , extrinsic transconductance ( $g_{m, max}$ ) of 16.7 mS/mm, two-terminal off-state gate-drain breakdown voltage ( $BV_{GD}$ ) of −379 V, and three-terminal on-state drain-source breakdown voltage ( $BV_{DS}$ ) of 339 V. Besides, superior deep-UV sensing performance with high spectral responsivity (SR) of 1780 (810.2) A/W at wavelength ${\boldsymbol{\lambda }} = 250$ (300) nm are also achieved.

中文翻译：

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具有对称渐变宽隙沟道的 Al0.75Ga0.25N/AlxGa1-xN/Al0.75Ga0.25N/AlN/SiC 金属氧化物半导体异质结构场效应晶体管

新型 Al _0.75 Ga _0.25 N/Al _x Ga _1-x N/Al _0.75 Ga _0.25 N/AlN 金属-氧化物-半导体异质结构场效应晶体管 (MOS-HFET)，具有对称渐变宽间隙 Al _x Ga _1-x N 通道（X $=\,\,0.75 \to 0.25 \to 0.75$ ) 生长在 SiC 衬底上进行了研究。通过使用非真空超声喷雾热解沉积 (USPD) 技术，将Al ₂ O ₃设计为栅极电介质。研究了关于源极/漏极凹槽的不同蚀刻深度的器件特性。对于 2- $\mu \text{m}$ 栅极长度 ( $L_{G}$ )，目前的宽隙 V 形沟道 MOS-HFET 已显示出改进的最大漏源电流密度 ( $I_{DS，最大}$ ) 299.3 A/mm 在 ${V_{DS}} = 20$ Ⅴ、 $I_{DS}$ 密度在 $V_{GS} = 0$ V ( $I_{DSS0}$ ) 的 153.9 mA/mm，开/关电流比 ( $I_{on}$ / $I_{off}$ ) 的 1.4 $\times 10^{7}$ , 外在跨导 ( $g_{m, max}$ ) 为 16.7 mS/mm，两端关态栅漏击穿电压 ( $BV_{GD}$ ) 的 −379 V，以及三端导通漏源击穿电压 ( $BV_{DS}$ ) 的 339 V。此外，卓越的深紫外传感性能，在波长处具有 1780 (810.2) A/W 的高光谱响应率 (SR) ${\boldsymbol{\lambda }} = 250$ (300)nm也实现了。