標題: A study on the plating and wetting ability of ruthenium-tungsten multi-layers for advanced Cu metallization
作者: Kuo, Tai-Chen
Su, Yin-Hsien
Lee, Wen-Hsi
Liao, Wei-Hsiang
Wang, Yu-Sheng
Hung, Chi-Cheng
Wang, Ying-Lang
光電工程學系
Department of Photonics
關鍵字: Ru;RuW alloy;Wetting ability;Plating ability
公開日期: 16-八月-2016
摘要: In this study, the plating and wetting ability of Cu/Ruthenium-Tungsten (RuW)/silicon oxide (SiO2) multi-layer stacks were investigated. RuW alloy films were prepared on a SiO2 layer by sputtering, followed by a deposition of a Cu thin film by electro-plating. Scanning electron microscopy (SEM) top view images shows that Cu films can be electroplated on RuW, with smaller Cu nuclei size but in a more highly concentrated and uniform distribution than Cu films electroplated on Ta or TaN. The rate of Cu nucleation decreases and larger Cu clusters were formed on the RuW alloy films with increasing W content. Cu/RuW/SiO2 samples were annealed at 400 degrees C for 30 min and then characterized using SEM. There were fewer pin holes on the surface of a pure Cu/Ru stack compared to Cu/RuW multilayers. Cu/RuW/SiO2 multi -layers had fewer pin holes than Cu/Ta/SiO2 structures processed under similar conditions. The wetting angle, measured by SEM, of Cu on a RuW substrate (43) was still lower than that of Cu on a Ta substrate (123 degrees), which suggests that the adhesion strength of Cu onto RuW alloy is better than that onto Ta. Preliminary studies of Cu diffusion through 25 nm RuW layers at 650 degrees C showed no Cu penetration into the underlying Si in a Cu/RuW/Si multi-layer test structure. (C) 2016 Elsevier B.V. All rights reserved.
URI: http://dx.doi.org/10.1016/j.mee.2016.04.025
http://hdl.handle.net/11536/136166
ISSN: 0167-9317
DOI: 10.1016/j.mee.2016.04.025
期刊: MICROELECTRONIC ENGINEERING
Volume: 162
起始頁: 27
結束頁: 33
顯示於類別:會議論文