MULTI-LAYER MEMORY ARRAY AND MANUFACTURING METHOD OF THE SAME

摘要

A memory array includes a plurality of ridge-shaped multi-layer stacks extending along a first direction, and a hard mask layer formed on top of the plurality of ridge-shaped multi-layer stacks. The hard mask layer includes a plurality of stripes vertically aligned with the plurality of ridge-shaped multi-layer stacks, respectively, a plurality of bridges connecting adjacent ones of the stripes along a second direction orthogonal to the first direction, and a plurality of hard mask through holes between the plurality of bridges and the plurality of stripes.

主权项

1. A method for manufacturing a memory array, comprising:
forming a multi-layer stack on a surface of a substrate; forming a plurality of first through holes through the multi-layer stack along a vertical direction of the multi-layer stack from a top surface of the multi-layer stack to the surface of the substrate, the first through holes being arranged in equally spaced rows along a first direction along the surface of the substrate, and equally spaced columns along a second direction orthogonal to the first direction; forming a plurality of sacrificial pillars to fill in the first through holes; forming a hard mask layer over the multi-layer stack with the sacrificial pillars, the hard mask layer including a plurality of hard mask through holes exposing regions of the multi-layer stack between neighboring sacrificial pillars in each column of sacrificial pillars; forming a plurality of second through holes through the multi-layer stack along the vertical direction of the multi-layer stack from the top surface of the multi-layer stack to the surface of the substrate, the second through holes being vertically aligned with the hard mask through holes; and removing the sacrificial pillars filling in the first through holes, wherein the second through holes are connected with the first through holes to form a plurality of trenches extending along the second direction, and the trenches divide the multi-layer stack into a plurality of ridge-shaped stacks extending along the second direction.