A simple metallic bonding structure, has been developed consisting of a pure metal Nb and an alloy containing Sn, which can be employed to bond a semiconducting laser device and/or a silicon integrated circuit die to a submount with Au–Sn solder. Differential scanning calorimetry, transmission electron microscopy, and scanning electron microscopy reveal that the Nb layer acts effectively both as an adhesion layer to SiO2and diamond submounts and as a perfect diffusion barrier against Au–Sn solder. The metallization structure shows no indication of dewetting of the Au–Sn solder. The excellent bonding characters have been attributed to the unique metallurgical properties of Nb. ©1995 American Institute of Physics.