The self-heating effects in vacuum gate dielectric gate-all-around field effect transistors (GAA FETs) with vertically stacked 4-nm silicon nanowire (SiNW) channels are investigated by 3-D TCAD simulation. The cross-sectional dimension-dependent thermal conductivity model of the SiNW is proposed for the precise numerical simulation of self-heating effects based on the temperature-dependent thermal conductivity of the bulk silicon. The thermal conductivity model which was verified by published data indicates that thermal conductivity of 4-nm SiNW is greatly reduced to below 10 W/mK due to the pronounced phonon boundary scattering. Simulation results shows that the vacuum gate dielectric devices undergo more severe self-heating effects than the solid gate dielectric GAA SiNW FETs, resulting in more serious performance degradation. Multiple heat sources generated by the three-stacked SiNWs make heat generation and diffusion more difficult. An effective method is proposed to suppress the self-heating effects by increasing the spacing of the gas gap within in a certain range and the around ambient gas pressure.

中文翻译：

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真空栅介质栅环绕垂直堆叠硅纳米线场效应晶体管的自热效应研究

通过 3-D TCAD 模拟研究了具有垂直堆叠 4-nm 硅纳米线 (SiNW) 通道的真空栅介质环栅场效应晶体管 (GAA FET) 中的自热效应。提出了 SiNW 的横截面尺寸相关热导率模型，用于基于体硅的温度相关热导率的自热效应的精确数值模拟。已公布数据验证的热导率模型表明，由于明显的声子边界散射，4-nm SiNW 的热导率大大降低到 10 W/mK 以下。仿真结果表明，真空栅介质器件比固体栅介质 GAA SiNW FET 经历更严重的自热效应，导致更严重的性能下降。由三层堆叠的 SiNW 产生的多个热源使热量的产生和扩散更加困难。提出了一种通过在一定范围内增加气隙间距和周围环境气压来抑制自热效应的有效方法。