Study on thermal stability of all copper interconnect structures under thermal shock

Copper nanoparticles have become a new generation of chip interconnection materials with considerable application prospects due to their excellent electrical and thermal properties, good electromigration resistance, and low economic cost. Different all copper interconnects were prepared by air sintering and vacuum sintering respectively, and the thermal shock test was carried out. The mechanical and electrical properties of the interconnects after thermal shock cycle were tested. Combined with microstructure characterization and theoretical analysis, the influence of thermal shock conditions on the thermal stability of all-copper interconnects was studied. The experimental results indicated that the bonding strength of the all-copper interconnection structure decreased first and then increased slightly with the number of thermal shock cycles. After 1000 cycles, the interconnection structures prepared by air sintering and vacuum sintering still maintain good bonding strength, and the average shear strength is respectively 23.24 MPa and 25.01 MPa.