A semiconductor die comprises: a device portion comprising an array of semiconductor devices extending in a first direction; and at least one interface portion located adjacent to an axial end of the device portion in the first direction. The at least one interface portion has a staircase profile in a vertical direction. The interface portion comprises: a stack comprising a plurality of gate layers and a plurality of insulating layers alternatively stacked on top of one another, and memory layers interposed between each of the plurality of gate layers and the plurality of insulating layers.