Improvement of thermal management capability of AlN coatings via adjusting nitrogen pressure

The dielectric loss of Cu with high thermal conductivity is large at high frequency, which cannot meet the performance requirements in high-integrated circuits. There is an urgent need for materials to reduce its dielectric loss. In this paper, the thermal conductivity and dielectric properties of the AlN coating-Cu substrate system were controlled by changing the N 2 pressure. The results showed that the crystallinity of hcp-AlN in AlN coating increased significantly when the proportion of N 2 pressure was increased. With the increase of the N 2 pressure, the particle size on the surface and the roughness of the coating improved. The AlN coating prepared at high N 2 pressure had high dielectric constant and low dielectric loss at high frequency compared to those of the coatings prepared at low N 2 pressure. At the same time, the AlN coating prepared under high N 2 pressure on the Cu substrate did not decrease the thermal conductivity of Cu substrate. The AlN-Cu system prepared in this paper had high thermal conductivity and good dielectric properties, providing theoretical guidance for integrated circuit packaging and capacitor applications.