Three-dimensional memory device with self-aligned vertical conductive strips having a gate-all-around configuration and method of making the same

Abstract

A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, memory stack structures extending through the alternating stack, drain-select-level trenches that vertically extend through at least one drain-select-level electrically conductive layer and laterally extend along a first horizontal direction and divide each drain-select-level electrically conductive layer into multiple drain-select-level electrically conductive strips, and pairs of vertical conductive strips located within a respective one of the drain-select-level trenches. Each of the vertical conductive strips has a pair of vertical straight sidewalls that laterally extends along the first horizontal direction. Each drain-select-level electrode may have at least one drain-select-level electrically conductive layer and at least one vertical conductive strip.