Investigation of CuMn alloy in copper metallization process

• Main Authors: Hsiu-AnYen, 顏秀安
• Other Authors: Wen-Hsi Lee
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/47635966121957920535

碩士 === 國立成功大學 === 電機工程學系碩博士班 === 100 === In this study, the characteristics of CuMn alloy films and their applications as the diffusion barrier/Cu seed layer for interconnect in IC are explored. Using CuMn as the barrier layer could reduce the thickness, because it could act as the barrier layer and seed layer at the same time. It is mainly divided into three parts. Part I is investigation of barrier ability when changing manganese concentration. First, we deposited pure copper and CuMn alloy film (Mn 1 at.%, Mn 5 at.%, Mn 10 at.%) on SiO2 substrate to produce alloy films (150nm) / SiO2 structure. Then the microstructures of the CuMn films were analyzed after annealing by TEM and SIMS. Part II is the integration of CuMn films and low-k substrates, using five different substrates for comparison. And the behavior between the barriers and the substrates were investigated. First, we deposited CuMn film on the different substrates to produce alloy films (150nm) / substrate structure. Then in-situ resistance of the samples was measured to preliminarily judge diffusion situation. After annealing, the binding energy of Mn at the interface was analyzed by ESCA. Finally the microstructures and the depth profiles of the CuMn films after annealing were examined by TEM and SIMS. The results showed that the best barrier was formed in the integration between CuMn 5 at.% and FSG substrate. Part III is that Cu was electrodeposited on CuMn alloy film to investigate the properties of these CuMn films. After Cu was deposited on CuMn, the surface morphology were observed by SEM, and we used electrochemical impedance analysis to investigate the effect of Mn concentration on the plated copper. The results showed that CuMn 5 at.% alloy thin film could form good barrier after annealing and had the best property as the seed layer during electrodeposition. We concluded that the addition of Mn had benefit to electrodeposition.