The interdiffusion of Sn from AuSn solder with the barrier metal deposited on diamond

The metallization of diamond by ion beam assisted deposition (IBAD) and subsequent sputter deposition was investigated. IBAD was adopted to prepare three metallization schemes for diamond substrates, i.e., Ti/Ni, Ti/Cr and Ti/W. A AuSn solder layer was deposited onto these systems using a sputtering technique. Metallization samples were subsequently furnace annealed. Characterization of the multi-layered films was performed using Rutherford backscattering spectrometry. The results showed that the diamond/Ti/Ni/AuSn and diamond/Ti/W/AuSn systems exhibit poorer thermal stability owing to Sn from AuSn solder reacting with the barrier metal during annealing. However, the diamond/Ti/Cr/AuSn structure appeared to be stable during annealing.