High Selectivity in Dry Etching of Silicon Nitride over Si Using a Novel Hydrofluorocarbon Etch Gas in a Microwave Excited Plasma for FinFET
High Selectivity in Dry Etching of Silicon Nitride over Si Using a Novel Hydrofluorocarbon Etch Gas in a Microwave Excited Plasma for FinFET
复制标题
在微波激发等离子体中使用新型氢氟碳蚀刻气体对 FinFET 进行高选择性干法蚀刻氮化硅
DOI：
10.1149/06103.0029ecst
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
and T. Ohmi
中科院分区：
文献类型：
--
作者：
Y. Nakao;T. Matsuo;A. Teramoto;H. Utsumi;K. Hashimoto;R. Kuroda;Y. Shirai;S. Sugawa;and T. Ohmi
在小型化MISFET中，特别是在FinFET中，需要SiNx相对于Si的增加的蚀刻选择性用于栅极间隔物的形成。在这项工作中，SiNx对Si的选择性进行评估，使用一种新的氢氟烃蚀刻气体与微波激发的高密度等离子体。通过使用这种新型的蚀刻气体，与CH 3F相比，获得了SiNx对Si的更高的选择性。Si的刻蚀速率被抑制，由于在没有O2气体的Si表面上的碳氢化合物膜的沉积。结果表明，在靠近SiNx侧壁处，SiNx对Si的选择性比远离SiNx侧壁处有所降低。通过使用大于12sccm的新型CxHyFz气体的流速，即使在SiNx被蚀刻为40nm的等效厚度之后，也形成了没有Si凹陷的栅极间隔物。
Increased etch selectivity of SiNx over Si is required for the gate spacer formation in miniaturized MISFETs, especially in the FinFET. In this work, the selectivity of SiNx over Si is evaluated using a novel hydrofluorocarbon etch gas with a microwave excited high-density plasma. By using this novel etchant gas, a higher selectivity of SiNx over Si was obtained compared to CH3F. The etch rate of Si was suppressed due to the deposition of a hydrocarbon film on Si surface without O2 gas. It was found that the selectivity of SiNx over Si near the SiNx sidewall decreased compared that far from the SiNx sidewall. By using flow rates of more than 12 sccm of the novel CxHyFz gas, the gate spacer was formed without Si recess even after the SiNx was overetched for an equivalent thickness of 40 nm.