1. A method of manufacturing a magnetoresistive-based device having magnetic material layers formed over a first electrically conductive layer, the magnetic materials layers including a tunnel barrier layer formed between a first magnetic materials layer and a second magnetic materials layer, comprising: patterning a first hard mask over the second magnetic materials layer; removing the second magnetic materials layer unprotected by the first hard mask, to form a second magnetic materials; patterning a second hard mask over the tunnel barrier layer, the first hard mask, and sides of the second magnetic materials; and removing the tunnel barrier layer and the first magnetic materials layer unprotected by the second hard mask to form a tunnel barrier and first magnetic materials.