Integrated word line contact structures in three-dimensional (3d) memory array

A memory array comprising:

• a plurality of word lines (WLs) in a vertical stack, including at least a first WL, a second WL, and a third WL;
• a first WL insulating layer between the first WL and the second WL to electrically isolate the first WL from the second WL;
• a second WL insulating layer between the second WL and the third WL to isolate the second WL from the third WL;
• a first WL contact, a second WL contact, and a third WL contact in physical contact with the first WL, the second WL, and the third WL, respectively, wherein the second WL contact extends through the first WL contact and the third WL contact extends vertically through the first WL contact and through the second WL contact;
• a first isolation structure to isolate the second WL contact from the first WL contact, extend through the first WL, and end where a bottom section of the first WL meets a top section of the first WL insulating layer;
• and
• a second isolation structure to isolate the third WL contact from the second WL contact, extend through the second WL, and end where a bottom section of the second WL meets a top section of the second WL insulating layer.

A computing system comprising:

• a processor;
• and
• a memory array including:
• a plurality of word lines (WLs) in a vertical stack, including at least three WLs:
• a first WL, a second WL, and a third WL;
• a first WL insulating layer between the first WL and the second WL to electrically isolate the first WL from the second WL;
• a second WL insulating layer between the second WL and the third WL to isolate the second WL from the third WL;
• a first WL contact, a second WL contact, and a third WL contact in physical contact with the first WL, the second WL, and the third WL, respectively, wherein the second WL contact extends through the first WL contact and the third WL contact extends through the first WL contact and the second WL contact;
• a first isolation structure to isolate the second WL contact from the first WL contact, extend through the first WL, and end where a bottom section of the first WL meets a top section of the first WL insulating layer;
• and
• a second isolation structure to isolate the third WL contact from the second WL contact, extend through the second WL, and end where a bottom section of the second WL meets a top section of the second WL insulating layer.