Solid-state amorphization at tetragonal-Ta/Cu interfaces
Solid-state amorphization at tetragonal-Ta/Cu interfaces
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DOI：
10.1063/1.124559
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发表时间：
1999-08
影响因子：
4
通讯作者：
Kee-Won Kwon;Hoo-Jeong Lee;R. Sinclair
中科院分区：
文献类型：
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作者：
Kee-Won Kwon;Hoo-Jeong Lee;R. Sinclair
本文描述了在微电子器件的铜金属化结构中出现的四方形Ta/Cu界面处形成的薄非晶层。当在400和600 °C之间退火时，无序层生长至4 nm。由于Ta和Cu根据热力学数据是不混溶的，这是一个不寻常的观察。非晶相形成的机制，提出了使用物理和化学的考虑。当在600 °C下退火时，在距离界面高达5 nm的Ta层中检测到高含量的Cu。虽然界面反应促进了粘附，但建议使用足够厚的Ta底层以有效阻止Cu扩散。在bcc-Ta/Cu界面处既没有观察到固态非晶化，也没有观察到Cu扩散到Ta中。
This letter describes the formation of a thin amorphous layer at the tetragonal-Ta/Cu interfaces, which appear in copper metallization structures of microelectronic devices. The disordered layer grows up to 4 nm when annealed at between 400 and 600 °C. Since Ta and Cu are immiscible according to thermodynamic data, this is an unusual observation. A mechanism for the amorphous phase formation is proposed using both physical and chemical considerations. A high content of Cu is detected in the Ta layer up to 5 nm from the interface when annealed at 600 °C. Although the adhesion is promoted by the interface reaction, a sufficiently thick Ta underlayer is recommended for efficient blocking of Cu diffusion. Neither solid-state amorphization nor Cu diffusion into Ta is observed at bcc-Ta/Cu interfaces.