Journal Article

Investigation on the formation technique of SiGe Fin for the high mobility channel FinFET device

Yang, Hong, Xu, Gaobo, Cheng, Xiaohong, Wang, Guilei, Li, Junjie, Luo, Jun, Liu, Haoyan, Xu, Jing, Wang, Wenwu, Zan, Ying, Zhang, Qingzhu, Wang, Xiaolei, Du, Anyan, Zhao, Zhiqian, Li, JunFeng, Yin, Huaxiang, Li, Yongliang, Ma, Xueli

2020

Overview

In this work, SiGe Fin formation technique using shallow trench isolation (STI) first or STI last strategy for the high mobility channel FinFET device is systematically investigated. A 20 nm width and 35 nm height high crystalline quality of the Si 0.7 Ge 0.3 Fin formation for STI first scheme is demonstrated by utilizing a new developed Si Fin etching, Si Fin recess and SiGe selective epitaxial growth process. For the STI last strategy, a novel chemical mechanical planarization (CMP) treated three-layer SiGe strain relaxed buffer (SRB) is successfully fabricated and a 50 nm high crystal quality and atomically smooth surface Si 0.5 Ge 0.5 layer on this SRB is attained. Moreover, a spike annealing is employed to avoid the Si 0.5 Ge 0.5 Fin oxidation during STI densification with an acceptable STI etching rate. However, both a spike annealing and a lower temperature of traditional furnace at 850 °C or 750 °C suffer micro-trench issue during the Fin reveal process. Therefore, a new developed process, named as STI recess first, is developed to resolve both thermal instability and micro-trench issue at the same time. A minor Si 0.5 Ge 0.5 Fin loss with a sharp Si 0.7 Ge 0.3 SRB/Si 0.5 Ge 0.5 interfaces for STI last scheme is realized by utilizing this new developed STI recess first process.

• Publisher: Springer US,Springer Nature B.V
• Subject: Annealing / Annealing furnaces / Characterization and Evaluation of Materials / Chemical-mechanical polishing / Chemistry and Materials Science / Densification / Epitaxial growth / Etching / Investigations / Materials Science / Nanowires / Optical and Electronic Materials / Optimization / Oxidation / Silicon germanides / Spikes / Strain / Thermal instability