Comparison of Hydrogen-Induced Oxide Charges Among GaN Metal-Oxide-Semiconductor Capacitors with Al2O3, HfO2, or Hf0.57Si0.43Ox Gate Dielectrics
Comparison of Hydrogen-Induced Oxide Charges Among GaN Metal-Oxide-Semiconductor Capacitors with Al2O3, HfO2, or Hf0.57Si0.43Ox Gate Dielectrics
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DOI：
10.1149/2162-8777/ac8a70
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发表时间：
2022-08
影响因子：
2.2
通讯作者：
Y. Irokawa;M. Inoue;T. Nabatame;Y. Koide
中科院分区：
文献类型：
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作者：
Y. Irokawa;M. Inoue;T. Nabatame;Y. Koide
用电容-电压(C-V)法研究了氢气对Al_2O_3、HfO_2、Hf_(0.57)Si_(0.43)O_x栅介质GaN金属氧化物半导体(MOS)电容器的影响。氢暴露使所有的C-V曲线向负偏压方向移动，并且器件的氢响应是可逆的。当含氢气氛改成氮气时，C-V特性逐渐恢复到氮气中的初始值。与无偏压时相比，施加反向栅压加速了反转，表明氢以正的移动电荷的形式被吸收到介质(Hf0.57Si0.43Ox)中。这一结果与C-V曲线的移动方向是一致的，带正电的氢吸收到介质中会引起平带电压漂移。氢致C-V曲线的位移随介质的不同而不同。研究发现，使用HfO2基高k电介质的MOS器件的合并电荷大约是使用Al_2O_3的器件的两到四倍。在氧空位(Vos)捕获氢气的假设下，结果表明HfO2基高k介质中的Vos数目远远多于Al_2O_3基介质中的VOS数目。
The effect of hydrogen on GaN metal-oxide-semiconductor (MOS) capacitors with Al2O3, HfO2, or Hf0.57Si0.43O x gate dielectrics was studied using capacitance–voltage (C–V) measurements. Hydrogen exposure shifted all the C–V curves toward the negative bias direction, and the hydrogen response of the devices was reversible. When the hydrogen-containing ambient atmosphere was changed to N2, the C–V characteristics were found to gradually revert to the initial values in N2. Application of a reverse gate bias accelerated the reversion compared with that in the absence of a bias, indicating that hydrogen was absorbed into the dielectric (Hf0.57Si0.43O x ) as positive mobile charges. This result is consistent with the direction of the shift of the C–V curves; positively charged hydrogen absorbed into a dielectric can cause a flatband voltage shift. The hydrogen-induced shift of the C–V curves varied depending on the dielectric. MOS devices with HfO2-based high-k dielectrics were found to have approximately two to four times more incorporated charges than devices with Al2O3. Under the hypothesis that oxygen vacancies (VOs) trap hydrogen, the obtained results imply that the number of VOs in HfO2-based high-k dielectrics is much larger than that in Al2O3-based dielectrics.