Yang Jingwen, Chen Kun, Wang Dawei, Liu Tao, Sun Xin, Wang Qiang, Huang Ziqiang, Pan Zhecheng, Xu Saisheng, Wang Chen, Wu Chunlei, Xu Min, Zhang David Wei
School of Microelectronics, Fudan University, Shanghai 200433, China.
Shanghai Integrated Circuit Manufacturing Innovation Center Co., Ltd., Shanghai 201203, China.
Micromachines (Basel). 2023 Mar 7;14(3):611. doi: 10.3390/mi14030611.
In this paper, nanosheet deformation during channel release has been investigated and discussed in Gate-All-Around (GAA) transistors. Structures with different source/drain size and stacked Si nanosheet lengths were designed and fabricated. The experiment of channel release showed that the stress caused serious deformation to suspended nanosheets. With the guidance of the experiment result, based on simulation studies using the COMSOL Multiphysics and Sentaurus tools, it is confirmed that the stress applied on the channel from source/drain plays an important role in nanosheet deformation during the fabrication process. The deformation of Si nanosheets would cause a serious degradation of the device performance due to an inability to control the work function of the metal gate. This study proposed that the uniformly stacked GAA nanosheets structure could be successfully demonstrated with suitable channel stress engineering provided by fitting S/D size and an appropriate channel length. The conclusions provide useful guidelines for future stacked GAA transistors' design and fabrication.
本文对全栅（GAA）晶体管沟道释放过程中的纳米片变形进行了研究和讨论。设计并制造了具有不同源极/漏极尺寸和堆叠硅纳米片长度的结构。沟道释放实验表明，应力会使悬浮的纳米片产生严重变形。在实验结果的指导下，基于使用COMSOL Multiphysics和Sentaurus工具的模拟研究，证实了在制造过程中，源极/漏极施加在沟道上的应力在纳米片变形中起着重要作用。由于无法控制金属栅极的功函数，硅纳米片的变形会导致器件性能严重下降。该研究提出，通过拟合源极/漏极尺寸和合适的沟道长度提供适当的沟道应力工程，可以成功展示均匀堆叠的GAA纳米片结构。这些结论为未来堆叠GAA晶体管的设计和制造提供了有用的指导。
