Investigation on the Interface Thermal Resistance of Copper-Titanium

The heat interface thermal resistance between the dielectric layer (Cu) and the barrier layer (Ti) in the Through-silicon via (TSV) are studied with molecular dynamics (MD) methods. The Cu/Ti interface thermal resistance is temperature dependent. Within the temperature from 293 K to 693 K, the resistance increases as the temperature rises. The increase in temperature causes an increase in atomic vacancy defects at the interface, and the interfacial voids degrade the heat transfer performance. However, when the temperature is higher than 693 K, the vacancies transfer from the interface to the second nearest or further neighbor on the adjacent atomic layers, which reduces the lattice mismatches at high temperatures. Besides, the single Ti atoms cross through the interface to match the Cu lattice vacancy when the temperature is higher than 693 K. As a result, interface thermal resistance decreases as temperature rises from 693 K to 1093 K.