Multilayer Connection Structure and Making Method

A three-dimensional stacked IC device comprising:

• a stack of at least first, second, third and fourth contact levels;
• each contact level comprising a conductive layer and an insulation layer;
• first, second, third and fourth electrical conductors being within contact openings, the contact openings passing through portions of the stack of contact levels;
• the first, second, third and fourth electrical conductors extending to and in electrical contact with the first, second, third and fourth conductive layers, respectively;
• a dielectric liner circumferentially surrounding the second, third and fourth electrical conductors so that the second electrical conductor is electrically isolated from the first conductive layer, the third electrical conductor is electrically isolated from the first and second conductive layers, and the fourth electrical conductor is electrically isolated from the first, second and third conductive layers;
• and
• portions of the conductive layers at the conductive openings being recessed relative to the adjacent insulation layers with portions of the dielectric liners extending between said adjacent insulation layers to create dielectric liner portions electrically isolating, and providing enhanced electrical insulation between opposed conductive layers and electrical conductors.

A method for creating electrical conductors for an IC device, the IC device comprising a stack of contact levels, each contact level comprising a conductive layer and an insulation layer, the method comprising:

• forming a contact opening passing through a portion of the stack of contact levels thereby creating an exposed conductive layer edge and insulation layer edges;
• creating a recessed region in the conductive layer at the exposed conductive layer edge to create a recessed conductive layer edge;
• forming a dielectric liner within the contact opening covering the insulation layer edges and the recessed conductor layer edge with electrically insulating material deposited within the recessed region, the dielectric liner creating a lined contact opening;
• creating an electrical conductor within the lined contact opening using an electrically conductive material, the electrically insulating material within the recessed region electrically isolating the electrical conductor from the recessed conductor layer edge thereby providing enhanced electrical insulation between the electrical conductor and the surrounding conductive layer;
• and
• electrically connecting the electrical conductor to an underlying conductive layer.

A method for creating electrical conductors for a three-dimensional stacked IC device, the IC device comprising a stack of at least first, second, third and fourth contact levels, each contact level comprising a conductive layer and an insulation layer, the method comprising:

• forming contact openings passing through portions of the stack of contact levels thereby creating exposed conductive layer edges and insulation layer edges;
• creating recessed regions in the conductive layers at the exposed conductive layer edges between adjacent insulation layers at the contact openings to create recessed conductive layer edges;
• forming dielectric liners within the contact openings covering the insulation layer edges and the recessed conductor layer edges with electrically insulating material deposited within the recessed region, the dielectric liner defining lined contact openings;
• creating first, second, third and fourth electrical conductors within the lined contact openings using an electrically conductive material, the electrically insulating material within the recessed regions electrically isolating the second, third and fourth electrical conductors from the conductive layers at the first contact level, the first and second contact levels, and the first, second and third contact levels, respectively, thereby providing enhanced electrical insulation between the electrical conductors and the surrounding conductive layers;
• and
• the electrical conductors creating step comprising extending the first, second, third and fourth electrical conductors to, and electrically connecting the first, second, third and fourth electrical conductors with, the conductive layers of the first, second, third and fourth contact levels, respectively.