Semiconductor memory structure and manufacturing method thereof

Abstract

Methods and apparatus for fabricating memory devices are provided. In one aspect, an intermediate stack of dielectric layers are formed on a first stack of dielectric layers in a first tier. The intermediate stack of dielectric layers is then partially or fully etched and have a landing pad layer deposited thereon. In response to planarizing the landing pad layer to expose a top surface of the intermediate stack of dielectric layers, a second stack of dielectric layers are deposited above the planarized landing pad layer. A staircase is formed by etching through the second stack, the intermediate stack, and the first stack of dielectric layers in the staircase region of the memory device. The staircase is located adjacent to one end of the center landing pad, where steps of the staircase are formed within the thickness of the center landing pad.