Composite target sputtering for forming doped phase change materials

A method for forming a memory cell, comprising:

• forming a bottom electrode structure on a substrate;
• forming a layer of phase change memory material having a silicon or silicon based additive on the bottom electrode by sputtering, using a sputter target including at least 30 at % silicon, and a phase change material including two or more elements;
• and
• forming a top electrode on the layer of memory material.

A method for forming a layer of phase change material with a dielectric additive formed by reaction of an additive element with oxygen or nitrogen, comprising:

• mounting a sputter target in a chamber, the sputter target including more than five times greater concentration of the additive element in the sputter target than specified for the layer, and a phase change material including two or more elements;
• mounting a substrate in the chamber;
• applying conditions in the chamber to induce sputtering;
• and
• adding one or both of oxygen and nitrogen to the chamber while applying said conditions to induce sputtering.