MULTI-LEVEL CONTACT TO A 3D MEMORY ARRAY AND METHOD OF MAKING

摘要

A method of making multi-level contacts. The method includes providing an in-process multilevel device including at least one device region and at least one contact region. The contact region includes a plurality of electrically conductive layers configured in a step pattern. The method also includes forming a conformal etch stop layer (122) over the plurality of electrically conductive layers, forming a first electrically insulating layer (124) over the etch stop layer, forming a conformal sacrificial layer (126) over the first electrically insulating layer and forming a second electrically insulating layer (128) over the sacrificial layer. The method also includes etching a plurality of contact openings (130A-E) through the etch stop layer, the first electrically insulating layer, the sacrificial layer and the second electrically insulating layer in the contact region to the plurality of electrically conductive layers.