Multilevel contact to a 3D memory array and method of making thereof

摘要

A multi-level device includes at least one device region and at least one contact region. The contact region has a stack of alternating plurality of electrically conductive layers and plurality of electrically insulating layers located over a substrate. The plurality of electrically conductive layers form a stepped pattern in the contact region, where each respective electrically insulating layer includes a sidewall and a respective underlying electrically conductive layer in the stack extends laterally beyond the sidewall. Optionally, a plurality of electrically conductive via connections can be formed, which have top surfaces within a same horizontal plane, have bottom surfaces contacting a respective electrically conductive layer located at different levels, and are isolated from one another by at least one trench isolation structure.

主权项

1. A method of fabricating a multilevel structure, comprising:
forming a stack including an alternating plurality of electrically conductive layers and electrically insulating layers over a substrate; forming a recessed region through the stack, wherein top surfaces of a first set of electrically conductive layers located at different levels are physically exposed within the recessed region; forming a first electrically conductive spacer directly on the top surfaces of the first set of electrically conductive layers within the recessed region; and forming at least one trench isolation structure extending through the stack, wherein the at least one trench isolation structure divides the first electrically conductive spacer into a plurality of electrically conductive via connections.