An Intel blog post details the manufacturing process behind Lakefield, an upcoming Core processor featuring "hybrid" technology-- specifically a means to mix power-efficient Tremont cores with a performance-scalable Sunny Cove core.
Dubbed Foveros, the process stacks components in three dimensions, making something of a silicon layer cake (if one just 1mm thick). Such packaging technology allows Chipzilla to "mix and match" technology IP blocks with various memory and I/O elements in a small physical package, allowing for "significantly reduced" board size.