A semiconductor die comprises: a first semiconductor device and a second semiconductor device. The first semiconductor device comprises a first device portion comprising a first sub-array of memory devices, and a first interface portion located adjacent to the first device portion in a first direction. The first interface portion has a staircase profile in a vertical direction. The second semiconductor device comprises a second device portion adjacent to the first device portion in the first direction opposite the first interface portion. The second device portion comprises a second sub-array of memory devices, and a second interface portion located adjacent to the first device portion in the first direction opposite the first interface portion. The second interface portion also has a staircase profile in the vertical direction. The first semiconductor device is electrically isolated from the second semiconductor device.