A method for fabricating three dimensional integrated circuits comprises providing a wafer stack wherein a plurality of semiconductor dies are mounted on a first semiconductor die, forming a molding compound layer on the first side of the first semiconductor die, wherein the plurality of semiconductor dies are embedded in the molding compound layer. The method further comprises grinding a second side of the first semiconductor die until a plurality of through vias become exposed, attaching the wafer stack to a tape frame and dicing the wafer stack to separate the wafer stack into a plurality of individual packages.