A semiconductor package including a plurality of stacked semiconductor die, and methods of forming the semiconductor package, are disclosed. In order to ease wirebonding requirements on the controller die, the controller die may be mounted directly to the substrate in a flip chip arrangement requiring no wire bonds or footprint outside of the controller die. Thereafter, a spacer layer may be affixed to the substrate around the controller die to provide a level surface on which to mount one or more flash memory die. The spacer layer may be provided in a variety of different configurations.