Broadband dielectric response of AlN ceramic composites

Aluminium nitride (AlN) is considered as a substrate material for microelectronic applications. AlN ceramic composites with different amount of TiO2 (up to 4 vol.%) were obtained using hot pressing at different sintering temperature from 1700 to 1900 degrees C. It was shown that milling of the raw AlN powder has strongly influence on sintering and improves densification. Broadband dielectric spectroscopy was used as a nondestructive method for monitoring of the ceramic microstructures. TiO2 additive affects the key properties of AlN ceramics. Thus, porosity of 0.1 %, dielectric permeability of sigma = 9.7 and dielectric loss tangent of tan ffi = 1.3.10(-3) can be achieved if up to 2 vol.% TiO2 is added.