Corrugated tier support structure and replacement source interior channel poly metalized lateral contact flow

A semiconductor device, comprising:

• a support on a substrate, wherein the support comprises a substantially planar first surface and a second surface opposite the first surface, wherein the second surface comprises an array of flutes separated by voids, and wherein the flutes extend along a first direction;
• tiers on the first surface of the support, the tiers comprising a stack of alternating dielectric layers and nitride layers, wherein the dielectric layers and nitride layers are arranged in planes substantially parallel to a plane of the first surface of the support;
• and
• a plurality of openings extending through the tiers and terminating in apertures extending through the support, wherein the openings extend along a second direction normal to the first direction, and wherein the apertures are arranged such that each opening overlies a void between two adjacent flutes in the support.

A method for making a semiconductor device, the method comprising:

• forming a substrate comprising an arrangement of conductive source lines;
• forming a support on the substrate, wherein the support has a first major surface and an opposed second major surface on the substrate, and wherein the second major surface of the support comprises a cavity;
• forming an arrangement of vias extending from the first major surface to the second major surface of the support, wherein the vias terminate in the cavity;
• depositing tiers comprising alternating dielectric layers and nitride layers on the first major surface of the support;
• forming openings in the tiers, wherein the openings extend in a first direction normal to a plane of the support, and wherein each of the openings terminates in an aperture in the support;
• depositing a channel poly material in the openings to form a first channel poly layer on walls thereof and a second channel poly layer on walls of the cavity, wherein the first channel poly layer forms a plug in a region of the opening adjacent to the cavity;
• etching an arrangement of slits in the tiers, wherein the slits are aligned with the source lines in the substrate;
• forming second openings in the slits, wherein the second openings in the slits form access regions to the cavity;
• etching to remove the first channel poly layer and the second channel poly layer;
• forming passages through the substrate to the source lines;
• and
• depositing a conductive material in the cavity and the passages to form an ohmic contact between the first channel poly layer and the source lines in the substrate.