1/ $f$ Noise Characteristics of Surface-Treated Normally-Off Al2O3/GaN MOSFETs
1/ $f$ Noise Characteristics of Surface-Treated Normally-Off Al2O3/GaN MOSFETs
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DOI：
10.1109/led.2015.2394373
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发表时间：
2015-01
影响因子：
4.9
通讯作者：
S. Sakong;Sanghyun Lee;T. Rim;Y. Jo;Jung-Hee Lee;Y. Jeong
中科院分区：
文献类型：
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作者：
S. Sakong;Sanghyun Lee;T. Rim;Y. Jo;Jung-Hee Lee;Y. Jeong
通常关闭Al2O3/GaN mosfet是用四甲基氢氧化铵（TMAH）处理作为栅极凹槽蚀刻制备的。利用低频（1/f）噪声和电容电压（C-V）测量研究了表面处理对蚀刻GaN表面的影响。为了与传统器件进行定量比较，使用统一的1/f噪声模型提取氧化物陷阱密度（Not），而使用高低频C-V方法提取界面陷阱密度（Dit）。经TMAH处理后，与传统器件相比，Not从5.40 × 1019 eV-1cm-3降低到2.50 × 1019 eV-1cm-3，而Dit从2.8 × 1012降低到1.1 × 1011 eV-1cm-2。因此，表面处理可以通过平滑表面和抑制凹槽GaN表面的等离子体损伤来降低Al2O3/GaN mosfet中的陷阱密度。
Normally off Al2O3/GaN MOSFETs are fabricated with a tetramethylammonium hydroxide (TMAH) treatment as a postgate recess etch. The effects of the surface treatment on the etched GaN surface are investigated using low-frequency (1/f ) noise and capacitance-voltage (C-V) measurements. For a quantitative comparison with conventional devices, the oxide trap density (Not) is extracted using the unified 1/f noise model, whereas the interface trap density (Dit) is extracted using the high-low-frequency C-V method. After the TMAH treatment, Not is found to have decreased from 5.40 × 1019 to 2.50 × 1019 eV-1cm-3, whereas Dit is decreased from 2.8 × 1012 to 1.1 × 1011 eV-1cm-2, as compared with conventional devices. The surface treatment is thus shown to lower trap density in the Al2O3/GaN MOSFETs by smoothing the surface and suppressing plasma damage in the recessed GaN surfaces.