Resistive ram including air gaps between word lines and between vertical bit lines

Abstract

A plurality of alternating stacks laterally spaced apart by line trenches is provided over a substrate. Each alternating stack includes respective word lines and respective dielectric material layers. An alternating sequence of vertical bit lines and inter-bit-line cavities is formed within each of the line trenches. Resistive memory material layers including resistive memory elements are provided at intersection regions between the word lines and the vertical bit lines. Air gaps are formed by removing at least a predominant portion of each of the dielectric material layers selective to the word lines, the vertical bit lines, and the resistive memory material layers, thereby forming a plurality of alternating stacks of the word lines and air gaps. A dielectric isolation layer including vertically-extending voids can be formed over the plurality of alternating stacks in the inter-bit-line cavities.