Patent ID: 9524901
Filing Date: 2016-12-20
CPC Classification: H01L

Claim Text:
1. A method of making multi-level contacts, comprising: providing an in-process multilevel device comprising a device region and a contact region comprising a stack of plurality of alternating sacrificial layers and insulating layers located over a major surface of a substrate; providing a contact mask with a plurality of contact mask openings over the stack; providing a first over mask with a plurality of first over mask openings over the contact mask, wherein a first subset of the plurality of contact mask openings is substantially aligned with the plurality of first over mask openings; forming a plurality of contact openings, wherein each of the plurality of contact openings extends substantially perpendicular to the major surface of the substrate through the stack to a respective one of the sacrificial layers; depositing a plurality of electrically conductive via contacts in the plurality of the contact openings; forming an insulating liner on a sidewall of each of the plurality of contact openings prior to depositing the plurality of electrically conductive via contacts; forming a trench through the stack; selectively removing the sacrificial layers from the stack through the plurality of contact openings and through the trench to form a plurality of recesses, wherein the plurality of recesses comprise a first recess in the first device level located over the major surface of the substrate and a second recess in the second device level located lower than the first device level over the major surface of the substrate; and depositing a plurality of electrically conductive electrodes in the plurality of recesses through the trench; wherein: