Kim Seong-In, Jeong Gi-Ppeum, Lee Seung-Jae, Lee Jong-Chan, Lee Jun-Myeong, Park Jin-Hyung, Bae Jae-Young, Park Jea-Gun
Department of Nanoscale Semiconductor Engineering, Hanyang University, Seoul 04763, Korea.
Department of Electronic Engineering, Hanyang University, Seoul 04763, Korea.
Nanomaterials (Basel). 2021 Dec 4;11(12):3296. doi: 10.3390/nano11123296.
For scaling-down advanced nanoscale semiconductor devices, tungsten (W)-film surface chemical mechanical planarization (CMP) has rapidly evolved to increase the W-film surface polishing rate via Fenton-reaction acceleration and enhance nanoscale-abrasive (i.e., ZrO) dispersant stability in the CMP slurry by adding a scavenger to suppress the Fenton reaction. To enhance the ZrO abrasive dispersant stability, a scavenger with protonate-phosphite ions was designed to suppress the time-dependent Fenton reaction. The ZrO abrasive dispersant stability (i.e., lower HO decomposition rate and longer HO pot lifetime) linearly and significantly increased with scavenger concentration. However, the corrosion magnitude on the W-film surface during CMP increased significantly with scavenger concentration. By adding a scavenger to the CMP slurry, the radical amount reduction via Fenton-reaction suppression in the CMP slurry and the corrosion enhancement on the W-film surface during CMP performed that the W-film surface polishing rate decreased linearly and notably with increasing scavenger concentration via a chemical-dominant CMP mechanism. Otherwise, the SiO-film surface polishing rate peaked at a specific scavenger concentration via a chemical and mechanical-dominant CMP mechanism. The addition of a corrosion inhibitor with a protonate-amine functional group to the W-film surface CMP slurry completely suppressed the corrosion generation on the W-film surface during CMP without a decrease in the W- and SiO-film surface polishing rate.
对于缩小先进的纳米级半导体器件，钨（W）膜表面化学机械平面化（CMP）已迅速发展，通过加速芬顿反应提高W膜表面抛光速率，并通过添加清除剂抑制芬顿反应来增强纳米级磨料（即ZrO）在CMP浆料中的分散剂稳定性。为了提高ZrO磨料分散剂的稳定性，设计了一种含质子化亚磷酸根离子的清除剂来抑制随时间变化的芬顿反应。ZrO磨料分散剂的稳定性（即较低的HO分解速率和较长的HO罐寿命）随清除剂浓度呈线性且显著增加。然而，CMP过程中W膜表面的腐蚀程度随清除剂浓度显著增加。通过向CMP浆料中添加清除剂，CMP浆料中通过抑制芬顿反应导致的自由基量减少以及CMP过程中W膜表面的腐蚀增强，使得W膜表面抛光速率通过化学主导的CMP机制随清除剂浓度增加而线性且显著降低。否则，SiO膜表面抛光速率通过化学和机械主导的CMP机制在特定清除剂浓度下达到峰值。向W膜表面CMP浆料中添加具有质子化胺官能团的腐蚀抑制剂，完全抑制了CMP过程中W膜表面的腐蚀产生，且W膜和SiO膜表面抛光速率没有降低。
