Exploration of Physics and Integration of Nano-Scale MOSEFET with Suppressed Fluctuations

这项研究的目的是研究抑制尺寸波动的纳米级MOSEFET的物理特性，并将新现象应用于集成电路器件。利用电子束光刻和刻蚀技术，研制出了尺寸小于10 nm的纳米器件。制备的器件在室温下出现量子效应和单电子荷电效应。在极窄沟道小于10 nm的MOSFET中，由于窄沟道中电子基态能量的升高，阈值电压升高。我们提出了一种利用这一效应来控制纳米MOSFET阈值电压的新方法。模拟还表明，超窄沟道MOSFET的电子迁移率和空穴迁移率都有所增加。另一方面，在点接触MOSFET中，在室温下观察到了由单电子充电效应引起的库仑阻塞振荡。硅点是在源极和漏极之间自形成的，该器件充当单电子或单孔晶体管。我们制作了直径为2 nm的点接触MOSFET。在室温下，库仑阻塞振荡的峰谷电流比大于40。还观察到了共振隧穿引起的负差分电导。首次使用单孔晶体管演示了使用单个器件的双输入逻辑操作。

The purpose of this research is to investigate the physics in nano-scale MOSEFET with suppressed size fluctuations and to apply new phenomena to integrated circuit devices. We have developed the fabrication process of nano-devices with dimensions less than 10nm by means of electron beam lithography and etching. Quantum effects and single-electron charging effect appear at room temperature in the fabricated devices. In the MOSFET with extremely narrow channel less than 10nm, the increase in threshold voltage is observed due to the rise of ground energy of electrons in narrow channel. We have proposed a new method to control threshold voltage in nano-scale MOSFET using this effect. It is also shown by simulation that electron and hole mobility increases in ultra-narrow channel MOSFET. On the other hand, Coulomb blockade oscillations due to single-electron charging effect is observed at room temperature in point-contact MOSFETs. A silicon dot is self-formed between source and drain and the device acts as a single-electron or single-hole transistor. We fabricated a point-contact MOSFET with a dot of 2nm diameter. The peak-to-valley current ratio of the Coulomb blockade oscillations is over 40 at room temperature. Negative differential conductance due to resonant tunneling is also observed. The two-input logic operation using a single device is demonstrated for the first time using a single-hole transistor.