Chakraborty Gargi, Sarkar C K, Lu X B, Dai J Y
Department of Electronics and Telecommunication Engineering, Jadavpur University, Kolkata, India.
Nanotechnology. 2008 Jun 25;19(25):255401. doi: 10.1088/0957-4484/19/25/255401. Epub 2008 May 14.
The tunnelling currents through the gate dielectric partly embedded with semiconducting single-wall carbon nanotubes in a silicon metal-oxide-semiconductor (MOS) structure have been investigated. The application of the gate voltage to such an MOS device results in the band bending at the interface of the partly embedded oxide dielectric and the surface of the silicon, initiating tunnelling through the gate oxide responsible for the gate leakage current whenever the thickness of the oxide is scaled. A model for silicon MOS structures, where carbon nanotubes are confined in a narrow layer embedded in the gate dielectric, is proposed to investigate the direct and the Fowler-Nordheim (FN) tunnelling currents of such systems. The idea of embedding such elements in the gate oxide is to assess the possibility for charge storage for memory device applications. Comparing the FN tunnelling onset voltage between the pure gate oxide and the gate oxide embedded with carbon nanotubes, it is found that the onset voltage decreases with the introduction of the nanotubes. The direct tunnelling current has also been studied at very low gate bias, for the thin oxide MOS structure which plays an important role in scaling down the MOS transistors. The FN tunnelling current has also been studied with varying nanotube diameter.
研究了在硅金属氧化物半导体（MOS）结构中，通过部分嵌入半导体单壁碳纳米管的栅极电介质的隧穿电流。向这种MOS器件施加栅极电压会导致在部分嵌入的氧化物电介质与硅表面的界面处发生能带弯曲，每当氧化物厚度缩小时，就会引发通过负责栅极泄漏电流的栅极氧化物的隧穿。提出了一种硅MOS结构模型，其中碳纳米管被限制在嵌入栅极电介质的窄层中，以研究此类系统的直接隧穿电流和福勒-诺德海姆（FN）隧穿电流。将此类元素嵌入栅极氧化物中的想法是评估用于存储器件应用的电荷存储可能性。比较纯栅极氧化物和嵌入碳纳米管的栅极氧化物之间的FN隧穿起始电压，发现随着纳米管的引入，起始电压降低。对于在缩小MOS晶体管尺寸方面起重要作用的薄氧化物MOS结构，还研究了在非常低的栅极偏置下的直接隧穿电流。还研究了不同纳米管直径下的FN隧穿电流。
