Electrical reliability and interfacial adhesion of Cu(Mg) thin films for interconnect process adaptability

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• 作者：Seol-Min Yi ; Jung-Uk An ; Sang-Soo Hwang ; Jung Ryoul Yim ; Yong-Hak Huh ; Young-Bae Park ; Young-Chang Joo
• 关键词：Cu(Mg) alloy ; Reliability ; Adhesion ; Interconnect
• 刊名：Thin Solid Films
• 出版年：2008
• 出版时间：29 February 2008
• 年：2008
• 卷：516
• 期：8
• 页码：2325-2330
• 全文大小：716 K

文摘

The process adaptability of Cu(0.7–1.2 at. % Mg) alloy films for microelectronics interconnects was investigated by comparing their electrical properties, interfacial adhesion strength, time dependent dielectric breakdown (TDDB) reliabilities, and interfacial microstructure with those of pure Cu. The resistivity of the Cu(Mg) films decreased to 2.0 μΩ cm after annealing them in a vacuum at 350 °C for 10 min. The interfacial debonding energy measured by the four-point bending method was approximately 20.1 J/m² for Cu(Mg)/SiO₂ which is a factor of 2.3 larger than that of Cu/SiO₂ interfaces. The median time to failure of Cu(Mg)/SiO₂ in the TDDB test was much larger than that of pure Cu/SiO₂. The diffusion of Cu into the dielectric was found to be inhibited by the continuous very thin Mg–O layer formed at the Cu(Mg)/SiO₂ interface, which improves the interfacial adhesion, and ultimately leads to better electrical reliabilities.