Low switching current dual spin filter (DSF) element for STT-RAM and a method for making the same

A dual spin filter (DSF) structure in a STT-RAM device, comprising:

• (a) a stack of layers formed on a bottom electrode with a top surface, said stack of layers has a certain shape in a plane parallel to said top surface, comprising;
• (1) a seed layer on the bottom electrode;
• (2) a first anti-ferromagnetic (AFM) layer that forms in direct contact with the seed layer;
• (3) a first pinned layer disposed on the first AFM layer;
• (4) a crystalline MGO tunnel barrier'
• (5) a free layer having a FM1/NCC/FM2 configuration formed on the MgO tunnel barrier where FM1 and FM2 are ferromagnetic layers made of Fe, Co, Ni, FeB, or crystalline CoFeB, and NCC is nano-current channel layer made of FeSiO, FeSiN, MSiO, MSiN, or MSiON where M is a metal and M and MSiO, MSiN, and MSiON are composites in which conductive M(Si) grains are magnetically coupled with the adjacent FM1 and FM2 layers and are formed in an oxide, nitride, or oxynitride insulator matrix, the FM1 layer contacts the tunnel barrier and the FM2 layer forms in direct contact with an overlying non-magnetic spacer;
• (6) the non-magnetic spacer layer on the free layer;
• (7) a second pinned layer formed on the non-magnetic spacer layer;
• (8) a second AFM layer on the second pinned layer;
• and
• (9) a capping layer wherein a Ru layer contacts the second AFM layer.