Method for fabricating MRAM bits on a tight pitch

摘要

A method for fabricating magnetoresistive random access memory (MRAM) devices on a tight pitch is provided. The method generally includes etching a pattern of columns into a hardmask layer disposed on a magnetic tunnel junction (MTJ) disposed on a substrate having electrically conductive contacts, the MTJ comprising a tunnel barrier layer between first and second ferromagnetic layers, the pattern of columns aligned to the electrically conductive contacts; etching the first ferromagnetic layer to expose the tunnel barrier layer and to form columns comprising the hardmask layer and the first ferromagnetic layer; forming a passivation layer on the exposed tunnel barrier layer and on top side surfaces of the columns; and etching the passivation layer on the exposed tunnel barrier layer, the exposed tunnel barrier layer, and the second ferromagnetic layer to form columns comprising the hardmask layer, the first ferromagnetic layer, the tunnel barrier layer, and the second ferromagnetic layer.

主权项

1. A method for fabricating a magnetoresistive random access memory (MRAM) device, comprising:
etching a pattern of first columns into a hardmask layer disposed on a magnetic tunnel junction (MTJ) stack that is disposed on a substrate having one or more electrically conductive contacts, wherein the MTJ stack comprises a tunnel barrier layer between first and second ferromagnetic layers, and wherein the pattern of first columns is aligned to the one or more electrically conductive contacts, wherein the hardmask layer is disposed on and in contact with the first ferromagnetic layer; etching the first ferromagnetic layer to expose the tunnel barrier layer and to form second columns comprising the hardmask layer and the first ferromagnetic layer; forming a passivation layer on the exposed tunnel barrier layer and on top surfaces and side surfaces of the second columns; and etching the passivation layer on the exposed tunnel barrier layer, the exposed tunnel barrier layer, and the second ferromagnetic layer to form third columns comprising the hardmask layer, the first ferromagnetic layer, the tunnel barrier layer, and the second ferromagnetic layer, wherein etching the second ferromagnetic layer exposes the one or more electrically conductive contacts and the substrate.