Aluminum Doped Hafnium Dioxide as Ferroelectric Material in MOS Structure

• Main Authors: Chu, Ka-lip, 朱家立
• Other Authors: Wu, Yung-Hsien
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/03177908406549474330

碩士 === 國立清華大學 === 工程與系統科學系 === 103 === Ferroelectric material and its fabrication have been researched for decades, but it still suffers from many drawbacks which makes it cannot be commercialized. Recently these problems seem to be possible to be solved because ferroelectricity in Hf-based material has been induced successfully. On the other hand, negative capacitance in ferroelectric material which is a plan to overcome limit of 60mV/dec subthreshold swing also attracts many engineers’ interest. In this thesis, how to induce ferroelectricity of Hf0.95Al0.05OX in MFIS sturcure will be discussed. It will be useful to someone who wants to fabricate FEMFET or FeFET. Comparing with MFM symmetric structure, the authors successfully prove that it is feasible to induce ferroelectricity of Hf0.95Al0.05OX without bottom electrode in appropriate annealing condition. Ferroelectricity is confirmed by P-E curve, clockwise C-V curve. It is suit for low voltage operation for a large C-V hysteresis window. Besides, bi-stable current direction is observed in device, which has potential to develop novel memory device. In our incipient research, it not only demonstrates good endurance and retention but also be verified appropriate P/E pulse time.