We present a model based on k · p theory which is able to capture the subband structure effects present in ultra-thin strained silicon nanowires. For electrons, the effective mass and valley minima are calculated for different crystal orientations, thicknesses, and strains. The actual enhancement of the transport properties depends highly on the crystal orientation of the nanowire axis; for certain orientations strain and confinement can play together to give a significant increase of the electron mobility. We also show that the effects of both strain and confinement on mobility are generally more pronounced in nanowires than in thin films. We show that optimal transport properties can be expected to be achieved through a mix of confinement and strain. Our results are in good agreement with recent experimental findings.

我们提出了一个基于k  ·  p的模型该理论能够捕捉超薄应变硅纳米线中存在的子带结构效应。对于电子，计算不同晶体取向、厚度和应变的有效质量和谷值最小值。传输特性的实际增强很大程度上取决于纳米线轴的晶体取向；对于某些方向，应变和限制可以共同作用以显着增加电子迁移率。我们还表明，应变和限制对迁移率的影响通常在纳米线中比在薄膜中更明显。我们表明，可以通过限制和应变的混合来实现最佳的传输特性。我们的结果与最近的实验结果非常吻合。