Solid state interracial reactions in electrodeposited Cu/Sn couples

• Published in: Transactions of Nonferrous Metals Society of China no. 1; pp. 90 - 96
• Main Author: 汤文明 HE An-qiang LIU Qi D. G IVEY
• Format: Journal Article
• Language: English
• Published: 2010
• Subjects: 固态反应; 微结构; 生长动力学; 电镀铜; 退火温度; 金属硅
• ISSN: 1003-6326

Cu/Sn couples, prepared by sequentially electroplating Cu and Sn layers on metallized Si wafers, were employed to study the microstructures, phases and the growth kinetics of Cu-Sn intermediate phases, when electroplated Cu/Sn couples were aged at room temperature or annealed at temperatures from 373 K to 498 K for various time. Only Cu6Sn5 formed in aged couples or couples annealed at temperature below 398 K. The Cu6Sn5 layer was continuous, but not uniform, with protrusions extending into the Sn matrix. When Cu/Sn couples were annealed at temperatures from 423 K to 498 K, two continuous and uniform Cn6Sn5/Cu3Sn layers formed within the reaction region between Sn and Cu. There were many voids near the Cu3Sn/Cu interface and within the Cu3Sn layer. Cu6Sn5 and Cu3Sn formations both follow parabolic growth kinetics with activation energies of 41.4 kJ/mol for Cu6Sn5 and 90.4 kJ/mol for Cu3Sn, respectively.