Three-dimensional memory device having double-width staircase regions and methods of manufacturing the same

Abstract

A three-dimensional memory device includes alternating stacks of insulating layers and electrically conductive layers located over a substrate. Each alternating stack within the plurality of alternating stacks is laterally spaced apart from one another by a network of interconnected trenches that extend through each level of the insulating layers and the electrically conductive layers. Groups of memory stack structures extend through a respective one of the alternating stacks. The network of interconnected trenches includes first lengthwise trenches laterally extending along a first horizontal direction by a first lateral trench extension distance, second lengthwise trenches laterally extending along the first horizontal direction and interlaced with the first lengthwise trenches to provide a laterally alternating sequence, and widthwise trenches connecting an end of a respective one of the second lengthwise trenches to a portion of a sidewall of a first lengthwise trench. The staircase regions provide a compact layout.