US Patent 11005036 Magnetoresistance structure including two hard masks

A magnetoresistance structure includes a base that includes a conductive layer and a first active element on and in direct contact with the conductive layer. The magnetoresistance structure also includes a pillar structure connected to the base. The pillar structure includes a first hard mask, a capping material, a second active element and a tunnel layer. The magnetoresistance structure also further includes an etching barrier deposited on the pillar and the base; a second hard mask deposited on the etching barrier; and a capping barrier deposited on the second hard mask and covering side walls of the base.