论文标题
N-和P型MOS2场效应晶体管的界面状态密度的全能谱
Full energy spectra of interface state densities for n- and p-type MoS2 field-effect transistors
论文作者
论文摘要
二维（2D）分层材料有望取代SI，以克服最近〜5 nm长的金属氧化物 - 氧化物 - 氧化物 - 氧化型野外晶体管（MOSFET）的缩放极限。但是，绝缘体/2D通道接口严重降低了2D基MOSFET的性能，并且降解的起源在很大程度上尚未探索。在这里，我们基于全面和系统的研究，即厚度范围从单层到散装，以及包括H-BN的2D异质结构以及典型的高k顶部结构，以及各种栅极堆栈结构。对于N-MOS2，对于H-BN，H-BN从5*10^12 cm-2ev-1的异质结构FET大幅度降低至5*10^11 cm-2ev-1，对于高k顶部的MOS2 FET。另一方面，即使对于P-MOS2的异质结构FET，DIT仍然保持〜10^13 cm-2ev-1。该系统的研究阐明了通过底物表面粗糙度和高K沉积过程向外部诱导的应变是导谱带侧界面降解的起源，而硫酸化诱导的缺陷量则占据了价值带侧的界面降解。目前对接口属性的理解为进一步改善2D FET的性能提供了关键。
Two-dimensional (2D) layered materials are promising for replacing Si to overcome the scaling limit of recent ~5 nm-length metal-oxide-semiconductor field-effect transistors (MOSFETs). However, the insulator/2D channel interface severely degrades the performance of 2D-based MOSFETs, and the origin of the degradation remains largely unexplored. Here, we present the full energy spectra of the interface state densities (Dit) for both n- and p- MoS2 FETs, based on the comprehensive and systematic studies, i.e., thickness range from monolayer to bulk and various gate stack structures including 2D heterostructure with h-BN as well as typical high-k top-gate structure. For n-MoS2, Dit around the mid gap is drastically reduced to 5*10^11 cm-2eV-1 for the heterostructure FET with h-BN from 5*10^12 cm-2eV-1 for the high-k top-gate MoS2 FET. On the other hand, Dit remains high, ~10^13 cm-2eV-1, even for the heterostructure FET for p-MoS2. The systematic study elucidates that the strain induced externally through the substrate surface roughness and high-k deposition process is the origin for the interface degradation on the conduction band side, while sulfur-vacancy-induced defect-states dominate the interface degradation on the valance band side. The present understanding on the interface properties provides the key to further improving the performance of 2D FETs.
