Slit oxide and via formation techniques

Abstract

Methods and apparatuses for slit oxide and via formation techniques are described, for example, for fabricating three dimensional memory devices that may include multiple decks of memory cells that each include memory cell stacks and associated access lines. The techniques may create an interconnect region without removing a portion of the memory cell stacks. The interconnect region may include one or more conductive vias extending through the decks of memory cells to couple the access lines with logic circuitry that may be located underneath the decks of memory cells. Further, the techniques may divide an array of memory cells into multiple subarrays of memory cells by forming trenches, which may sever the access lines. In some cases, each subarray of memory cells may be electrically isolated from other subarrays of memory cells. The techniques may reduce a total number of fabrication process steps.