Manufacturing techniques and devices for magnetic tunnel junction devices

A method for forming a semiconductor device, the method comprising:

• providing a semiconductor substrate;
• forming a bottom electrode layer over the semiconductor substrate;
• forming a magnetic tunneling junction (MTJ) layer over the bottom electrode layer;
• forming a top electrode layer over the MTJ layer;
• and
• performing an etch operation to etch the bottom electrode layer, the MTJ layer, and the top electrode layer to form a first bottom electrode and a second bottom electrode corresponding to the bottom electrode layer, a first MTJ and a second MTJ corresponding to the MTJ layer, and a first top electrode and a second top electrode corresponding to the top electrode layer, wherein the first bottom electrode and the second bottom electrode are electrically insulated from each other and the etch operation exposes an etch stop layer laterally located between the first and second bottom electrodes.

A method for forming a semiconductor device, the method comprising:

• forming a pair of memory cells over a substrate, wherein forming the pair of memory cells includes:
• forming a bottom electrode layer over an interconnect structure;
• forming a cap layer over the pair of memory cells;
• and
• prior to forming the cap layer, performing an etch operation on the bottom electrode layer to form a pair of bottom electrodes, wherein a residue of the etch operation is between the cap layer and a sidewall of at least one of the bottom electrodes.