Explorations on Long-Range Coulomb Interactions in Bulk Silicon
|關鍵字:||電漿子;電位擾動;能隙窄化;遷移率;plasmons;potential fluctuations;bandgap narrowing;mobility|
Driven by Moore’s law, the channel length of silicon MOSFETs has been aggressively scaled to nanometer region in the past decades, and will enter 5-nm technology node in the next years. In this situation, the generated potential fluctuations in the highly-doped source and drain regions will penetrate into channel and deteriorate the device performance. To make the physical picture clear, figuring out the underlying mechanisms at the semiconductor level is fundamental and crucial. Thus we focus on two well-known experimental points for the bulk silicon. One is the apparent bandgap narrowing, and another is the electron mobility in n-type silicon. In this thesis, we first extract the magnitudes of potential fluctuations in the heavily doped region via the experimental data of enhanced minority-carrier injection which has been explained by the apparent bandgap narrowing in the past. Through the theoretical calculations, the plasmon is verified as the main origin of potential fluctuations. Then we further conduct the microscopic mobility calculations with the extracted potential fluctuations taken into account. The calculated results can reproduce the experimental data well. For the regions with potential fluctuations, electron-plasmon interactions are important and need to be taken seriously. The scattering formalism has been published in the literature, which is quite complicated and not easy to understand. In the end, we also propose physical based model as the alternative way to deal with such problem. The model is much simple, making the extension flexible.
|Appears in Collections:||Thesis|