Phonon-scattering effects in CNT-FETs with different dimensions and dielectric materials

详细信息    查看全文

• 作者：Roberto Grassi ; Stefano Poli ; Susanna Reggiani ; Elena Gnani ; Antonio Gnudi ; Giorgio Baccarani
• 关键词：Quantum transport ; Carbon nanotube ; Non-equilibrium Green’ ; s function formalism ; Phonon scattering ; Band-to-band tunneling
• 刊名：Solid-State Electronics
• 出版年：2008
• 出版时间：September 2008
• 年：2008
• 卷：52
• 期：9
• 页码：1329-1335
• 全文大小：464 K

文摘

The impact of acoustic and optical phonon scattering on the performance of CNT-FETs is investigated using a full-quantum transport model within the NEGF formalism. Different gate lengths, dielectric materials and chiralities are considered. It is shown that the use of a high-κ dielectric lowers the off-current dominated by phonon-assisted band-to-band tunneling. The device scalability is demonstrated: with the oxide thickness fixed to 1.5 nm, good performance is obtained with 15 nm and 10 nm gate lengths with SiO₂ and HfO₂ gate dielectrics, respectively. The role of phonon scattering in CNT-FETs of different chiralities is investigated for the HfO₂ devices. A similar analysis has also been carried out for source/drain underlap geometries. The results confirm that the calculation of the off-currents and delay times is strongly influenced by phonon scattering.