As the IC technology is evolving very rapidly, the feature size of the device has been migrating to sub-nanometre regime for achieving the high packing density. To continue with further scaling of ICs, some novel devices such as multiple-gate silicon-on-insulator (SOI) devices, Gate-All-Around (GAA) nanowire and Nanotube MOSFETs have been proposed by researchers in recent years. The short channel transistor below 10 nm needs to have ultra-sharp junctions at source and drain ends with the channel region. The creation of such a sharp junction is quite challenging process from fabrication point of view. Therefore, junctionless transistors (JLT) were proposed to eradicate junction’s related issues, exhibit full CMOS functionality. The multigate junctionless transistors have been proposed, designed and fabricated. This paper illustrated basic working mechanism and behaviour of the various single and multi-gate junctionless MOSFETs. Junctionless nanowires transistor with single circular gate and gate material engineered techniques has also been explained. From simulation results, it has been observed that junctionless Nanotube GAA MOSFET has shown superior electrical behaviour over the Nanowire GAA MOSFET. Junctionless GaAs-Nanotube MOSFET has shown tremendous response over Junctionless Si-Nanotube MOSFET in terms of leakage and ON current. Junctionless GaAs-Nanotube MOSFET may be observed as alternate candidate for future CMOS applications.

随着IC技术的发展日新月异，该器件的功能尺寸已迁移至亚纳米级，以实现高封装密度。为了进一步扩大IC规模，近年来，研究人员提出了一些新颖的器件，例如多栅极绝缘体上硅（SOI）器件，全能栅极（GAA）纳米线和纳米管MOSFET。低于10 nm的短沟道晶体管需要在源极和漏极端具有沟道区域的超尖结。从制造的角度来看，这种尖锐的结的创建是非常具有挑战性的过程。因此，提出了无结晶体管（JLT）来消除结的相关问题，展现出完整的CMOS功能。已经提出，设计和制造了多栅极无结晶体管。本文阐述了各种单栅极和多栅极无结MOSFET的基本工作机制和性能。还已经解释了具有单圆形栅极和栅极材料工程技术的无结纳米线晶体管。从仿真结果可以看出，无结Nanotube GAA MOSFET表现出比Nanowire GAA MOSFET更好的电性能。在无结Si-纳米管MOSFET方面，无结GaAs-纳米管MOSFET在漏电流和导通电流方面显示出巨大的响应。无结GaAs纳米管MOSFET可能会被视为未来CMOS应用的替代选择。从仿真结果可以看出，无结Nanotube GAA MOSFET表现出比Nanowire GAA MOSFET更好的电性能。在无结Si-纳米管MOSFET方面，无结GaAs-纳米管MOSFET在漏电流和导通电流方面显示出巨大的响应。无结GaAs纳米管MOSFET可能会被视为未来CMOS应用的替代选择。从仿真结果可以看出，无结Nanotube GAA MOSFET表现出比Nanowire GAA MOSFET更好的电性能。在无结Si-纳米管MOSFET方面，无结GaAs-纳米管MOSFET在漏电流和导通电流方面显示出巨大的响应。无结GaAs纳米管MOSFET可能会被视为未来CMOS应用的替代选择。