隧穿场效应晶体管中齐纳隧穿的理论研究

项目名称： 隧穿场效应晶体管中齐纳隧穿的理论研究

项目编号： No.11464032

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 宫箭

作者单位： 内蒙古大学

项目金额： 50万元

中文摘要： 由于隧穿场效应晶体管在降低能耗、突破亚阈值摆幅限制等方面的优势，受到广泛关注。然而，对于理解器件的物理本质和提高器件性能方面的研究尚不充分。本项目拟从密度泛函理论出发，采用非局域平面波赝势方法，探讨隧穿场效应晶体管器件中Zener隧穿的物理本质，通过分析散射态，正确理解电子从价带性质向导带性质的转化，获得电子波矢在带隙中的转变途径，利用所得结论，对传统基于有效质量近似的WKB方法和k.p方法作合理修正，利用修正后模型对隧穿场效应晶体管进行模拟。通过ab initio计算，细致讨论沟道区杂质和缺陷的物理性质，获得陷阱态辅助隧穿的机理，讨论杂质与缺陷位置和浓度对器件开启电流和亚阈值幅摆的影响。深入分析材料声子模特性，对合金半导体材料获得较准确的电子-声子相互作用，结合传统处理电子跃迁的方法研究声子辅助带间隧穿。以期解释和预言新物理现象，推动隧穿场效应晶体的优化设计，指导新型半导体器件的研制。

中文关键词： 齐纳隧穿；第一性原理；声子；缺陷；隧穿场效应晶体管

英文摘要： The tunneling field-effect transistor has received tremendous attentions due to its potential to reduce the power consumption by decreasing the supply voltage and to overcome the subthreshold swings limitation of 60 mV/decade at room temperature for traditional Metal-Oxide-Semiconductor transistors. However, it is still insufficient about the research of the working principle of tunneling field-effect transistor and how to improve the performance of the device. Based on density fuctional theory, we will investigate the physical mechanism of Zener tunneling in the tunneling field-effect transistor by using the plane-wave non-local pseudopotential method. By analyzing the scattering state of electron, we also hope to understand how a electron transforms from the valence band-like properties to the conduction band-like properties. The process of the electrons from the valence band tunnel through the band gap to the conduction band will be described clearly. According to the results obtained, we will develop a general formalism for band-to-band tunneling by combining the traditional effective mass and K.P method. Then the tunnel field-effect transistors will be simulated accurately by using this corrected method. Trap assisted tunneling is an important aspect of experimental tunnel field-effect transistors, which are today the most promising devices for next-generation low-power transistors. A fundamental understanding of the mechanism of trap assisted tunneling is need. We will disscuss the physical properties of the impurities and defects in the channel region by the detailed ab initio calculation. The effect of trap location, trap energy and trap density on on-current and subthreshold swings (SS) will be studied in detail. An accurate electron-phonon interaction for semiconductor compound material will be obtained to discuss phonon-assisted band to band tunneling. We will find a framework to calculate the current due to phonon-assisted tunneling in indirect semiconductors. We believe that our results will be helpful to optimize the tunneling field-effect transistors design and develop the new devices.

英文关键词： Zener tunneling;first principle calculation;phonon;defect;tunnel field-effect transistors