CMOS-compatible RF/microwave devices, such as filters and amplifiers, have been widely used in wireless communication systems. However, secondary-electron emission phenomena often occur in RF/microwave devices based on silicon (Si) wafers, especially in the high-frequency range. In this paper, we have studied the major factors that influence the secondary-electron yield (SEY) in commercial Si wafers with different doping concentrations. We show that the SEY is suppressed as the doping concentration increases, corresponding to a relatively short effective escape depth λ. Meanwhile, the reduced narrow band gap is beneficial in suppressing the SEY, in which the absence of a shallow energy band below the conduction band will easily capture electrons, as revealed by first-principles calculations. Thus, the new physical mechanism combined with the effective escape depth and band gap can provide useful guidance for the design of integrated RF/microwave devices based on Si wafers.

中文翻译：

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硅片二次电子发射的物理机制

CMOS兼容的射频/微波器件，例如滤波器和放大器，已广泛应用于无线通信系统中。然而，二次电子发射现象经常发生在基于硅（Si）晶片的射频/微波器件中，特别是在高频范围内。在本文中，我们研究了影响不同掺杂浓度的商用硅片二次电子产率（SEY）的主要因素。我们发现，随着掺杂浓度的增加，SEY 受到抑制，对应于相对较短的有效逃逸深度λ。同时，减小的窄带隙有利于抑制SEY，其中导带下方不存在浅能带，因此很容易捕获电子，正如第一原理计算所揭示的那样。因此，新的物理机制与有效逃逸深度和带隙相结合可以为基于硅片的集成射频/微波器件的设计提供有用的指导。