| abstract |
A semiconductor device with an improved solder joint system is described. The solder system includes two copper contact pads connected by a body of solder (120) and the solder is an alloy including tin, silver, and at least one metal from the transition groups IIIA, IVA, VA, VIA, VIIA, and VIIIA of the Periodic Table of the Elements. The solder joint system also includes, between the pads and the solder, layers of intermetallic compounds, which include grains of copper and tin compounds and copper, silver, and tin compounds. The compounds contain the transition metals. The inclusion of the transition metals in the compound grains reduce the compound grains size and prevent grain size increases after the solder joint undergoes repeated solid/liquid/solid cycles. |