Three-dimensional memory device with separated contact regions and methods for forming the same

A method of forming a memory die, comprising:

• forming an alternating stack of insulating layers and spacer material layers over a substrate, wherein the spacer material layers are formed as, or are subsequently replaced with, electrically conductive layers, wherein the alternating stack laterally extends through a series of regions that comprises, in a spatial order along a first horizontal direction, a first contact region, a first memory array region, an auxiliary contact region, a second memory array region, and a second contact region;
• forming arrays of memory openings located in the first memory array region and the second memory array region;
• forming arrays of memory opening fill structures within the arrays of memory openings, wherein each of the memory opening fill structures comprises a respective vertical stack of memory elements, wherein the alternating stack comprises a lower layer stack including a first subset of the insulating layers and a first subset of the electrically conductive layers located underneath a horizontal plane, and an upper layer stack including a second subset of the insulating layers and a second subset of the electrically conductive layers located above the horizontal plane;
• forming first contact via structures contacting a respective electrically conductive layer of the first subset of the electrically conductive layers in the first contact region and the second contact region;
• and
• forming second contact via structures contacting a respective electrically conductive layer of the second subset of the electrically conductive layers in the auxiliary contact region.