Investigation of Metal Peeling Failure of Ti/Ni/Ag Metal Thin Films on Silicon Wafers

In this paper, failure analysis was conducted to investigate the root cause of Ti/Ni/Ag film peeling from silicon wafer surface. SEM and Edax analysis revealed that peeling was found at Ti/Si interface, and no contamination elements, such as C, H, O, were existed. VK Analyzer was used to measure the surface roughness, and the results revealed that the peeling failure was due to the low surface roughness resulted from excessive polishing after wafer back grinding process. Experiments for changing rabbling polishing method for bubbling polishing one were done expecting to realize high uniformity of surface roughness, and the results showed that roughness uniformity was greatly improved, and no peeling metal was left on the blue tape.