Unexpected equivalent-oxide-thickness dependence of the subthreshold swing in tunnel field-effect transistors
Unexpected equivalent-oxide-thickness dependence of the subthreshold swing in tunnel field-effect transistors
复制标题
隧道场效应晶体管中亚阈值摆幅的意外等效氧化物厚度依赖性
DOI：
10.7567/apex.7.024201
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发表时间：
2014
影响因子：
2.3
通讯作者：
H. Ota
中科院分区：
文献类型：
--
作者：
T. Mori;T. Yasuda;K. Fukuda;Y. Morita;S. Migita;A. Tanabe;T. Maeda;W. Mizubayashi;S. O'Uchi;Yongxun Liu;M. Masahara;N. Miyata;H. Ota
采用传统的平面HfO2/Si栅堆叠结构成功地制作出亚阈值摆幅最小为27 mV/ten的隧道场效应晶体管(TFET)。然而，与理想带间隧穿假设下的模拟结果相比，随着等效氧化层厚度(EOT)的增加，SS发生了意外的退化。我们发现，较差的亚阈值操作是由热激活过程控制的，这表明陷阱辅助隧道效应发生在冶金pn结附近。此外，我们还讨论了观察到的EOT敏感SS降解对器件生产的影响。
Tunnel field-effect transistors (TFETs) exhibiting a minimum subthreshold swing (SS) of 27 mV/decade were successfully fabricated using conventional planar HfO2/Si-gate-stack structures. However, an unexpected SS degradation with increasing equivalent oxide thickness (EOT) was observed compared with the simulated results obtained under the assumption of ideal band-to-band tunneling. We found that the poor subthreshold operation was governed by a thermally activated process, suggesting trap-assisted tunneling that occurs with traps near the metallurgical pn junction. Furthermore, we discuss the effect of the observed EOT-sensitive SS degradation on device production.