Methods of making magnetoresistive memory devices

A method of forming a magnetoresistive device, comprising:

• forming a stack comprising a first magnetic layer, a second magnetic layer, and a non-magnetic layer between the first and second magnetic layers;
• the second magnetic layer having an uppermost surface;
• forming a patterned mask over the second magnetic layer, the patterned mask defining a first pattern;
• extending the first pattern into the second magnetic layer, but not entirely through the second magnetic layer, with a first etching process;
• utilizing a second etching process, different than the first etching process, to extend the first pattern entirely through the second magnetic layer and to the non-magnetic layer, the second etching process being selective for material of the second magnetic layer relative to material of the non-magnetic layer;
• forming a dielectric material over the patterned second magnetic layer;
• the dielectric material extending over the uppermost surface of the second magnetic layer;
• and
• while the dielectric material remains over the uppermost surface of the second magnetic layer, utilizing a third etching process to extend a second pattern through the dielectric material, non-magnetic layer and first magnetic layer.

A method of forming a magnetoresistive device, comprising:

• forming a stack comprising a first magnetic layer, a second magnetic layer, and a non-magnetic layer between the first and second magnetic layers;
• forming a patterned mask over the second magnetic layer, the patterned mask defining a first pattern;
• extending the first pattern into the second magnetic layer, but not entirely through the second magnetic layer, with a first etching process;
• utilizing a second etching process, different than the first etching process, to extend the first Pattern entirely through the second magnetic layer and to the non-magnetic layer, the second etching process being selective for material of the second magnetic layer relative to material of the non-magnetic layer;
• forming a dielectric material over the Patterned second magnetic layer;
• forming an insulative material over the dielectric material;
• planarizing a surface of the insulative material;
• forming a patterned masking block over the planarized surface;
• the patterned masking block defining a second pattern;
• and
• utilizing a third etching process to extend the second Pattern through the insulative material, dielectric material, non-magnetic layer and first magnetic layer.

A method of forming a magnetoresistive device, comprising:

• forming a construction which includes a first tantalum-containing layer, a first magnetic layer over the first tantalum-containing layer, a non-magnetic layer over the first magnetic layer, a second magnetic layer over the non-magnetic layer, and a second tantalum-containing layer over the second magnetic layer;
• forming a first patterned masking block over the second tantalum-containing layer, the first patterned masking block defining a first pattern having a first peripheral shape;
• etching the second tantalum-containing layer and a portion of the second magnetic layer with a primarily physical etch to transfer the first peripheral shape to the second tantalum-containing layer and the portion of the second magnetic layer;
• after the etching with primarily physical etch, extending the first peripheral shape entirely through the second magnetic layer with a wet etch selective for the second magnetic layer relative to the non-magnetic layer;
• the wet etch exposing portions of the non-magnetic layer;
• forming a dielectric material over the etched second tantalum-containing layer, etched second magnetic layer, and exposed portions of the non-magnetic layer;
• after forming the dielectric material, forming a mass over the dielectric material and planarizing an upper surface of the mass;
• forming a second patterned masking block over the mass, the second patterned masking block defining a second pattern having a second peripheral shape, the second peripheral shape being different than the first peripheral shape;
• and
• utilizing a third etching process to extend the second pattern through the non-magnetic layer, first magnetic layer and first tantalum-containing layer.