Etching of magnetic tunnel junction (mtj) stack for magnetoresistive random-access memory (mram)

A method comprising:

• forming a first set of spacers on the sidewalls of a bottom electrode;
• forming a reference layer on the spacers and the bottom electrode;
• forming a second set of spacers on the sidewalls of the first set of spacers and the reference layer;
• forming a tunnel barrier on the reference layer and the second set of spacers;
• forming a free layer on the tunnel barrier, wherein a width of the free layer is greater than a width of the reference layer;
• forming a metal hardmask on the free layer;
• and
• forming a third set of spacers on the sidewalls of the metal hardmask, the free layer, the tunnel barrier, and the second set of spacers.

A semiconductor structure comprising:

• a magnetoresistive random-access memory (MRAM) cell, comprising:
• a free layer above a reference layer and separated from the reference layer by a tunnel barrier, wherein a width of the reference layer is less than a width of the free layer;
• and
• a bottom electrode under the reference layer, wherein a width of the bottom electrode is equal to the width of the reference layer.

A method comprising:

• forming a reference layer on a bottom electrode;
• forming a first set of spacers on the sidewalls of the reference layer and the bottom electrode;
• forming a tunnel barrier on the reference layer and the first set of spacers;
• forming a free layer on the tunnel barrier, wherein a width of the free layer is wider than a width of the reference layer;
• forming a metal hardmask on the free layer;
• and
• forming a second set of spacers on the sidewalls of the metal hardmask, the free layer, the tunnel barrier, and the first set of spacers.