Adhesion studies of CVD copper metallization

The adhesion of chemical vapor deposition (CVD) Cu thin films to various barriers was observed to improve with a post-deposition anneal or a physical vapor deposition (PVD) Cu flash layer on the barrier before depositing CVD Cu. The ambient exposure of the barrier before the deposition of CVD Cu has been observed to lead to degradation of adhesion in both CVD Cu seed and CVD/PVD Cu high vacuum integrated metallization schemes. The integrated CVD and PVD Cu deposition scheme exhibits better adhesion due to the inherent annealing provided during the PVD deposition which is carried out at temperatures between 300 and 400 degrees C. We have evaluated both qualitative and quantitative tests - tape test, Stud pull test and 4-point bend test - in understanding adhesion and observed that each of these tests give different details of interface breakdown. (C) 2000 Elsevier Science B.V. All rights reserved.