Analysis and Design of 2D Negative Capacitance FETs

• Main Authors: Lu, Po-Sheng, 呂勃陞
• Other Authors: Su, Pin
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/4t9xdb

碩士 === 國立交通大學 === 電子研究所 === 107 === In this thesis, we first investigate the remnant polarization (Pr) dependence of subthreshold and ON-state characteristics for the intrinsic and extrinsic 2D Negative-Capacitance FETs (2D NCFETs) with the aid of TCAD numerical simulation. For the intrinsic 2D NCFETs, the results show that the low-Pr ferroelectric may lead to better subthreshold swing but worse ON-current. We report a feedback mechanism for the 2D NCFETs with a low-Pr ferroelectric that can be utilized to mitigate the current degradation due to the presence of significant contact resistance. Moreover, we compare the Metal-Ferroelectric-Metal-Insulator-Semiconductor (MFMIS) and Metal-Ferroelectric-Insulator-Semiconductor (MFIS) types of 2D NCFETs regarding both near-threshold and ON-state characteristics with the aid of the segmented SPICE simulation. Our study indicates that the MFIS possesses better minimum swing, whereas the negative differential resistance (NDR) in the MFMIS can be utilized for analog applications. The distributed charge effect enhances the lateral electric field in the channel for the low-Pr MFIS, leading to higher ON-current than the MFMIS, but decreases the lateral electric field in the channel for the high-Pr MFIS, leading to lower ON-current than the MFMIS. Our study also shows that the multi-domain interaction of the ferroelectric boosts the distributed charge effect for the low-Pr MFIS, but diminishes it for the high-Pr MFIS, which both results in higher ON-current. The multi-domain interaction also increases the VD,sat for the MFIS.