Some embodiments include apparatuses and methods of forming the apparatuses. One of the apparatuses includes levels of conductive materials interleaved with levels of dielectric materials; memory cell strings including respective pillars extending through the levels of conductive materials and the levels of dielectric materials; a first dielectric structure formed in a first slit through the levels of conductive materials and the levels of dielectric materials; a second dielectric structure formed in a second slit through the levels of conductive materials and the levels of dielectric materials; the first dielectric structure and the second dielectric structure separating the levels of conductive materials, the levels of dielectric materials, and the pillars into separate portions, and the first and second dielectric structures including different widths.