Real time stress monitoring in reflow solder: Cu thin films in Si(111)

Substrate curvature method (SCM) is a versatile optical stress measuring method which owns a lot of merits: realtime, rapid, nondestructive, easily operating. A film stress measuring apparatus by SCM was developed, and stresses in Ag/Cu multilayer thin films and reflow solder on Cu thin films in Si(111) prepared by RF magnetron sputtering were detected. The stress-temperature behavior was studied. The stresses in Ag/Cu multilayer thin films were different due to different temperature. The stresses in reflow solder on Cu thin films in Si(111) were different due to the generation of excessive amounts of intermetallic compound. The results identify that the interfacial reaction kinetics has effect on wetting dynamics in evidence.