薄膜双栅MOSFET体反型现象的研究

A Study on the Volume Inversion in Thin Si-Film Double-Gate MOSFET's

通过对QM模型的介绍,说明了薄膜双栅MOSFET体反型现象是量子效应的结果,并对QM模型中提出的反型层质心概念进行了剖析,阐述了其重要的物理意义和应用价值。利用反型层质心概念,提出了一组形式非常简单,且与体硅单沟道MOSFET表达式十分相似的薄膜双栅MOSFET亚阈值区反型层载流子浓度和亚阈值电流的表达式,与MEDICI模拟结果的比较证明了其精确性。应用反型层质心及所提出的亚阈值区模型,对薄膜双栅MOSFET体反型现象进行了深入的分析,提出了一个能够较好体现体反型作用的硅膜厚度范围。

In the paper, it is clarified that volume inversion in thin Si-film double-gate (DG) MOSFET's is the result of quantum mechanism. The physical significance and practical value of the inversion-layer centroid, which is obtained in the QM model, are demonstrated and analyzed. Based on the inversion-layer centroid, expression of inversion-carrier density in the sub-threshold region and expression of the sub-threshold current are developed, which have very simple form and are similar to those of bulk-silicon single-gate (SG) MOSFET's. The accuracy of these expressions has been verified by MEDICI. Using the inversion-layer centroid and the sub-threshold model developed in the paper, an insight analysis of volume inversion in thin Si-film DG MOSFET's is made, and a range of Si-film thickness is proposed,which can effectively embody the effect of volume inversion.