Dielectric properties of silicon-doped α-alumina derived from sol–gel process

In this study, silicon-doped alumina (Al₂O₃) was synthesized using the sol–gel method. The composition and structure of silicon-doped alumina were analyzed using thermogravimetric-differential thermal analysis, X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. As a result, it was found that the particle size of the silicon-doped alumina was uniform, and the silicon doped in the α-Al₂O₃ lattice occupied the space of the oxygen octahedron to form a structure based on the Al–O–Si bond. Also, because of measuring the change in dielectric constant according to the amount of doped silicon, a value of the dielectric constant of 3.1 at 1 GHz frequency when the silicon doping amount was 2%. Therefore, it is thought to be applicable to the fields of microelectronics, electronic packaging and interconnection, small antenna arrays, and capacitors that require low-k materials.