Effects of Electroplating at Lower Leveler and Suppressor Contents on the Formation of Very Low Resistivity Narrow Cu Interconnects
Effects of Electroplating at Lower Leveler and Suppressor Contents on the Formation of Very Low Resistivity Narrow Cu Interconnects
复制标题
较低整平剂和抑制剂含量的电镀对极低电阻率窄铜互连形成的影响
DOI：
10.1149/2.0991904jes
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发表时间：
2019
影响因子：
3.9
通讯作者：
Onuki Jin
中科院分区：
文献类型：
--
作者：
Miyamoto Ryo;Tamahashi Kunihiro;Inami Takashi;Sasajima Yasushi;Onuki Jin
我们研究了整平剂和抑制剂含量对窄 50 nm 宽铜互连晶体结构的影响。与仅降低抑制剂或整平剂含量时相比，降低抑制剂和整平剂含量导致刚镀覆后晶粒尺寸更大的减小和退火后晶粒尺寸更大的增加。据报道，晶粒尺寸越细，晶界能越大。我们认为电镀后晶粒尺寸的减小是由于抑制剂或整平剂含量减少以及抑制剂和整平剂含量减少而导致的 Cu 成核增强所致。此外，通过将高纯度电解液（9N）与优化的抑制剂和整平剂含量相结合，退火后的平均晶粒尺寸比传统电镀条件增加了约25%，从而实现了低电阻率的窄铜线。这些结果被认为是由于使用具有优化的添加剂含量的9N电解液进行电镀获得的非常小的晶界和杂质含量少得多，从而大大增强了退火过程中的晶粒生长。根据拟合的实验曲线，可以预期电阻率低于3 μΩ·cm。
We investigated the effects of leveler and suppressor contents together on crystal structures of narrow 50 nm width Cu interconnects. Lowering both suppressor and leveler contents led to a bigger decrease in grain size just after plating and bigger increase in grain size after annealing than when just suppressor or leveler content was decreased. It is reported that the finer the grain size is, the larger the grain boundary energy is. We considered that grain size decrease after electroplating was due to nucleation enhancement of Cu by the decreased suppressor or leveler content, and by both decreased suppressor and leveler contents. Furthermore, by the combination of high purity electrolyte (9N) with optimized suppressor and leveler contents, the mean grain size after annealing was increased by about 25% over that of the conventional electroplating conditions, leading to realization of narrow Cu wires with low resistivity. These results were considered to be due to the fact that the very small grain boundaries with much smaller amounts of impurities, obtained by plating using 9N electrolyte with optimized additive contents, enhanced grain growth substantially during annealing. Electric resistivity under 3 μΩ· cm can be expected based on the fitted experimental curve.