Tung Nguyen Hoang, Lee Heesoo, Dinh Duy Khoe, Kim Dae-Woong, Lee Jin Young, Eom Geon Woong, Kim Hyeong-U, Kang Woo Seok
Mechanical Engineering, KIMM Campus, University of Science and Technology (UST), Daejeon 34113, Republic of Korea.
Semiconductor Manufacturing Research Center, Korea Institute of Machinery and Materials (KIMM), Daejeon 34103, Republic of Korea.
Sensors (Basel). 2024 May 13;24(10):3089. doi: 10.3390/s24103089.
Highly selective etching of silicon nitride (SiN) and silicon dioxide (SiO) has received considerable attention from the semiconductor community owing to its precise patterning and cost efficiency. We investigated the etching selectivity of SiN and SiO in an NF/O radio-frequency glow discharge. The etch rate linearly depended on the source and bias powers, whereas the etch selectivity was affected by the power and ratio of the gas mixture. We found that the selectivity can be controlled by lowering the power with a suitable gas ratio, which affects the surface reaction during the etching process. X-ray photoelectron spectroscopy of the SiN and QMS measurements support the effect of surface reaction on the selectivity change by surface oxidation and nitrogen reduction with the increasing flow of O. We suggest that the creation of SiON bonds on the surface by NO oxidation is the key mechanism to change the etch selectivity of SiN over SiO.
由于其精确的图案化和成本效益，氮化硅（SiN）和二氧化硅（SiO）的高选择性蚀刻受到了半导体领域的广泛关注。我们研究了在NF/O射频辉光放电中SiN和SiO的蚀刻选择性。蚀刻速率与源功率和偏置功率呈线性关系，而蚀刻选择性则受气体混合物的功率和比例影响。我们发现，通过在合适的气体比例下降低功率可以控制选择性，这会影响蚀刻过程中的表面反应。SiN的X射线光电子能谱和四极质谱测量结果支持了随着O流量增加，表面氧化和氮还原导致表面反应对选择性变化产生影响的观点。我们认为，通过NO氧化在表面形成SiON键是改变SiN相对于SiO蚀刻选择性的关键机制。
