Multilayered wiring substrate of aluminum nitride having a high

Abstract

An aluminum nitride multilayered wiring substrate and a method of manufacturing the wiring substrate are provided. The wiring substrate is provided with the high dielectric layer. Although the wiring substrate has no excessively multilayered structure, high capacitance can be easily obtained. The multilayered wiring substrate is a laminated body of an upper substrate layer, a capacitor layer and a lower substrate layer. Three aluminum nitride layers composing the upper substrate layer have interior peripheries arranged in a step fashion stepping down toward the center of the multilayered wiring substrate. The central part of the upper substrate layer is thinner than the periphery. The surfaces and inside of the upper substrate layer are provided with conductive layers. The capacitor layer is a laminated body of two high dielectric layers formed of aluminum nitride with titanium nitride added thereto for raising the specific dielectric constant. Conductive layers are also formed on both surfaces of the capacitor layer and on the interface between the high dielectric layers. The lower substrate layer is also a laminated body of two aluminum nitride layers.