Crystallization Behaviour of Electroless Ni-P UBM with Medium Phosphorous Induced by Single and Step Heat Treatment

This study examined the crystallization behavior of electroless Ni P UBM with an medium phosphorous content (similar to 15 at%) induced by a single and step heat treatment using in situ transmission electron microscopy (TEM) Different heat treatment processes affected the crystallization behavior of electroless Ni P UBM After single heat treatment at 300 degrees C for 60 min the electroless Ni P UBM contained Ni and Ni3P In addition to Ni and Ni3P more complex Ni P compounds such as Ni12P5 and Ni5P2 formed in the electroless Ni P UBM resulting from a step heat treatment at 150 C for 60 min followed by 300 C for 60 min [doi 10 2320/matertrans M2010178]