IBM Thomas J Watson Research Center, Yorktown Heights, New York 10598, USA.
Nano Lett. 2010 Sep 8;10(9):3572-6. doi: 10.1021/nl101832y.
We show that silicon nitride can provide uniform coverage of graphene in field-effect transistors while preserving the channel mobility. This insulator allowed us to study the maximum channel resistance at the Dirac (neutrality) point as a function of the strength of a perpendicular electric field in top-gated devices with different numbers of graphene layers. Using a simple model to account for surface potential variations (electron-hole puddles) near the Dirac point we estimate the field-induced band gap or band overlap in the different layers.
我们证明，氮化硅可以在保持沟道迁移率的同时，为场效应晶体管中的石墨烯提供均匀的覆盖。这种绝缘体使我们能够在不同层数的顶部栅极器件中，研究在垂直电场强度作用下，狄拉克（中性）点处的最大沟道电阻作为函数。我们使用一个简单的模型来解释在狄拉克点附近的表面电势变化（电子-空穴势阱），从而估计不同层中的电场诱导能带隙或能带重叠。
