Method of forming an on-pitch self-aligned hard mask for contact to a tunnel junction using ion beam etching

A method of forming a memory device, the method comprising:

• forming a magnetic tunnel junction on a first electrode using an electrically conductive mask and subtractive etch method;
• forming at least one dielectric layer to encapsulate the magnetic tunnel junction;
• removing said portion of the at least one dielectric layer that is present on the electrically conductive mask by ion beam etching to form a top contact for the magnetic tunnel junction, said ion beam etching comprising a collimated beam of argon focused onto the portion of the dielectric layer while the portion of the at least one dielectric layer being milled by the collimated beam is rotated simultaneously uniformly removing said portion of the dielectric layer;
• and
• forming a second electrode in contact with the electrically conductive mask.

A method of forming a memory device, the method comprising:

• forming a magnetic tunnel junction on a first electrode using an electrically conductive mask and subtractive etch method, the first electrode formed within a trench of a substrate;
• forming at least one dielectric layer to encapsulate the magnetic tunnel junction;
• forming a photoresist etch mask exposing a portion of the at least one dielectric layer that is present on the electrically conductive mask;
• and
• removing said portion of the at least one dielectric layer that is present on the electrically conductive mask by ion beam etching to form a top contact for the magnetic tunnel junction, said ion beam etching comprising a collimated beam of argon focused onto the photoresist etch mask and said portion of the dielectric layer while the portion of the at least one dielectric layer and the photoresist mask being milled by the collimated beam is rotated simultaneously uniformly removing said photoresist etch mask and said portion of the dielectric layer exposed by the photoresist etch mask.