Etch characteristics of nanoscale ultra low-k dielectric using C3H2F6
Etch characteristics of nanoscale ultra low-k dielectric using C3H2F6
复制标题
使用 C3H2F6 的纳米级超低 k 电介质的蚀刻特性
DOI：
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
G. Yeom
中科院分区：
文献类型：
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作者：
H. Tak;Junyoung Jang;D. Sung;D. Kim;Dongwoo Kim;G. Yeom
下一代半导体器件要求在线路结构的后端采用多孔SiCOH等超低介电常数(ULK)材料，以降低电阻和电容(RC)时延，但这些ULK材料在运行过程中容易受到等离子体的破坏
蚀刻。本研究采用双频电容耦合技术研究了纳米TiN掩蔽多孔SiCOH的刻蚀特性，如刻蚀速率、刻蚀轮廓、表面损伤等，以及采用C_3H_2F_6为基气体的等离子体特性
并与使用传统的C4F8基气体进行低k介电腐蚀的结果进行了比较。结果表明，对于相同的刻蚀速率和刻蚀轮廓，观察到了较低的侧壁损伤。
用C3H_2F_6与C_4F_8进行比较。分析表明，与C4F8相比，C3H2F6的UV(小于400 nm)发射更少，血浆中的氟自由基更少，
这使得C3H2F6中的氢对氟的清除作用减少了氟向刻蚀后的多孔SiCOH侧壁表面的扩散。
Next generation semiconductor devices require ultra low dielectric constant (ULK) materials such as porous SiCOH on the back end of line structure for lower resistance and capacitance (RC) time delay, however, these ULK materials are easily damaged by the exposure to plasmas during
the etching. In this study, etch characteristics of nanoscale TiN masked porous SiCOH such as etch rate, etch profile, surface damage, etc. and plasma characteristics by using C3H2F6 based gases have been investigated with a dual-frequency capacitively coupled
plasma system (DF-CCP) and the results were compared with those by using conventional C4F8 based gases used for low-k dielectric etching. The results showed that, for the similar etch rates and etch profiles of porous SiCOH, lower sidewall damage was observed for the
etching with the C3H2F6 compared to the C4F8. The analysis showed that it was related to less UV (less than 400 nm) emission and less fluorine radicals in the plasma for C3 H2F6 compared to C4F8,
which leads to less fluorine diffusion to the sidewall surface of the etched porous SiCOH by the fluorine scavenging by hydrogen in C3H2F6.